Passiflora caerulea ou passiflore bleue est une plante grimpante de la famille des Passifloraceae, originaire d'Amérique du Sud. C'est la passiflore ornementale la plus cultivée dans les pays tempérés.

Il existe plusieurs variétés cultivées1 de Passiflora caerulea :

Constance Eliot est résistante à des gelées de -15 °C, très florifère et très parfumée

China Blue a une couronne bleu clair

Clear sky est un cultivar tétraploïde

Beaucoup d'espèces du genre Passiflora peuvent s'hybrider entre elles. Dès le début du XIXe siècle, le premier croisement réussi fut celui de Passiflora caerulea et de P. racemosa pour donner P. × violacea. De même Passiflora × belotti provient du croisement de P. alata et de P. caerulea.

Description

Feuille pentalobée, vrille et bouton floral

La passiflore bleue est une plante grimpante, très vigoureuse, développant de longues tiges de 5-6 m, souples et anguleuses, s'accrochant à l'aide de vrilles.

Deux grosses stipules réniformes2 d'environ 2 cm de long sont à la base du pétiole portant la feuille. Le limbe de 5-8 × 6-9 cm comporte généralement 5 lobes palmés, à marge entière.

Coupe de fleur de Passiflora caerulea

L'inflorescence est une cyme dont la fleur centrale avorte, une fleur latérale se développe en vrille et l'autre donne une véritable fleur. Cette fleur, d'environ 8 cm de diamètre, porte :

3 grosses bractées ovales, vertes pâle

5 sépales pétaloïdes avec un éperon sous apical vert

5 pétales blanchâtres

une couronne de filaments tricolores disposés sur 2 niveaux. Les filaments sont colorés de bleu clair, blanc et pourpre foncé au centre. Suivent 1 ou 2 cycles de filaments courts avec nectaires à la base.

au centre, une colonne, l'androgynophore, de 8-10 mm hauteur, portant l'androcée et le gynécée :

5 étamines vertes clair à anthères jaunes tournées vers le bas

au-dessus de l'ovaire verdâtre se dressent 3 styles pourpres, unis à leur base et terminés par des stigmates réniformes.

La floraison a lieu de mai-juin à septembre. Elle s'accompagne du dégagement d'un doux parfum rappelant le monoï.

Le fruit est une baie jaune orangé, ovoïde ou subglobuleuse, d'environ 6 cm de long, contenant de nombreuses graines. Bien mûr, et bien que peu charnu et peu savoureux, il semble comestible en petites doses. Cru et encore vert, il contient de l'acide cyanhydrique3(0,0118-0,013 % de HCN).

Légende

Les missionnaires espagnols firent preuve d'imagination et s'en servirent pour enseigner l'histoire du Christ, en particulier de sa Passion :

- Les vrilles symbolisent les fouets de la flagellation

- les dix pétales et sépales représentent dix des douze apôtres

- la centaine de filets disposés en cercle fait allusion à la couronne d'épines.

- Les trois stigmates et les cinq anthères rappellent les trois clous et les cinq plaies.

Pollinisation

Passiflora caerulea avec styles dressés

Abeille récoltant le nectar de Passiflora caerulea avec styles rabattus

Passiflora caerulea ouverte vue de 3/4

Fleur de grenadille (Passiflora caerulea).jpg

La fleur reste ouverte un ou deux jours. À l'ouverture de la fleur, les styles sont redressés dans la position qu'ils occupaient dans le bouton floral. Puis rapidement les styles4 se rabaissent jusqu'à ce que les stigmates jouxtent les anthères. En fin de floraison, ils se redressent dans leur position antérieure.

Le pollen est libéré avant que les stigmates ne deviennent réceptifs (protandrie). Les grains de pollen sont gros, lourds et ne peuvent pas être emportés par le vent. C'est généralement des hyménoptères qui se chargent de la pollinisation. En France, l'abeille européenne et les bourdons sont les pollinisateurs les plus fréquents. Certains plants sont autofertiles mais d'autres comme la variété Constance Eliot, ne le sont pas.

Le moment le plus propice à la pollinisation se trouve lorsque les stigmates sont au niveau des anthères. À ce moment, les insectes en allant récolter le nectar (ou le pollen) abondamment fourni par la fleur se frottent aux stigmates qui à cet instant secrètent un liquide visqueux capable de capter le pollen éventuellement transporté par l'insecte.

Écologie

Passiflora caerulea est originaire d'une zone couvrant le Brésil, l'Argentine, le Paraguay et l'Uruguay.

Elle est cultivée comme ornementale dans les régions tempérées.

Elle s'est naturalisée et est même devenue envahissante dans certaines régions du monde, comme en Espagne5, en Californie, Hawaï et Nouvelle-Zélande6.

Composition

On sait que les membres du genre Passiflora contiennent des alcaloïdes, phénols, glucosides de flavonoïdes et des composés cyanogènes7. Des alcaloïdes de type harmane n'ont pas été trouvés dans P. caerulea.

Dans la fleur de Passiflora caerulea il a été isolé une flavone8, la chrysine, connue ou du moins vendue aux sportifs comme inhibiteur de l'aromatase (bien que des études in vivo n'aient montré aucune d'activité inhibitrice de l'aromatase9,10).

La plante fraiche écrasée libère rapidement une quantité importante de cyanure (30-40 μmol/g). Il a été isolé des glucosides cyanogènes : la gynocardine, un mélange épimère de sulfate de tétraphylline B et de sulfate d'épitétraphylline B11.

Le catabolisme normal des hétérosides cyanogènes conduit à la libération d'acide cyanhydrique qui est aussitôt converti en asparagine12.

From my astronomy archives. Made this image from my backyard back in 2005. Notes:

Lens: Takahashi FSQ 106

Camera: SBIG STL-11000M

Exposures: 3.5 hours Luminance plus 2 hours RGB over two nights.

Mount: Astro-physics 900GTO

Software: Cyanogen Maxim DL

m31_LRGB-TAK106_SBIG11000-1920b.jpg

Passiflora caerulea ou passiflore bleue est une plante grimpante de la famille des Passifloraceae, originaire d'Amérique du Sud. C'est la passiflore ornementale la plus cultivée dans les pays tempérés.

Il existe plusieurs variétés cultivées1 de Passiflora caerulea :

Constance Eliot est résistante à des gelées de -15 °C, très florifère et très parfumée

China Blue a une couronne bleu clair

Clear sky est un cultivar tétraploïde

Beaucoup d'espèces du genre Passiflora peuvent s'hybrider entre elles. Dès le début du XIXe siècle, le premier croisement réussi fut celui de Passiflora caerulea et de P. racemosa pour donner P. × violacea. De même Passiflora × belotti provient du croisement de P. alata et de P. caerulea.

Description

Feuille pentalobée, vrille et bouton floral

La passiflore bleue est une plante grimpante, très vigoureuse, développant de longues tiges de 5-6 m, souples et anguleuses, s'accrochant à l'aide de vrilles.

Deux grosses stipules réniformes2 d'environ 2 cm de long sont à la base du pétiole portant la feuille. Le limbe de 5-8 × 6-9 cm comporte généralement 5 lobes palmés, à marge entière.

Coupe de fleur de Passiflora caerulea

L'inflorescence est une cyme dont la fleur centrale avorte, une fleur latérale se développe en vrille et l'autre donne une véritable fleur. Cette fleur, d'environ 8 cm de diamètre, porte :

3 grosses bractées ovales, vertes pâle

5 sépales pétaloïdes avec un éperon sous apical vert

5 pétales blanchâtres

une couronne de filaments tricolores disposés sur 2 niveaux. Les filaments sont colorés de bleu clair, blanc et pourpre foncé au centre. Suivent 1 ou 2 cycles de filaments courts avec nectaires à la base.

au centre, une colonne, l'androgynophore, de 8-10 mm hauteur, portant l'androcée et le gynécée :

5 étamines vertes clair à anthères jaunes tournées vers le bas

au-dessus de l'ovaire verdâtre se dressent 3 styles pourpres, unis à leur base et terminés par des stigmates réniformes.

La floraison a lieu de mai-juin à septembre. Elle s'accompagne du dégagement d'un doux parfum rappelant le monoï.

Le fruit est une baie jaune orangé, ovoïde ou subglobuleuse, d'environ 6 cm de long, contenant de nombreuses graines. Bien mûr, et bien que peu charnu et peu savoureux, il semble comestible en petites doses. Cru et encore vert, il contient de l'acide cyanhydrique3(0,0118-0,013 % de HCN).

Légende

Les missionnaires espagnols firent preuve d'imagination et s'en servirent pour enseigner l'histoire du Christ, en particulier de sa Passion :

- Les vrilles symbolisent les fouets de la flagellation

- les dix pétales et sépales représentent dix des douze apôtres

- la centaine de filets disposés en cercle fait allusion à la couronne d'épines.

- Les trois stigmates et les cinq anthères rappellent les trois clous et les cinq plaies.

Pollinisation

Passiflora caerulea avec styles dressés

Abeille récoltant le nectar de Passiflora caerulea avec styles rabattus

Passiflora caerulea ouverte vue de 3/4

Fleur de grenadille (Passiflora caerulea).jpg

La fleur reste ouverte un ou deux jours. À l'ouverture de la fleur, les styles sont redressés dans la position qu'ils occupaient dans le bouton floral. Puis rapidement les styles4 se rabaissent jusqu'à ce que les stigmates jouxtent les anthères. En fin de floraison, ils se redressent dans leur position antérieure.

Le pollen est libéré avant que les stigmates ne deviennent réceptifs (protandrie). Les grains de pollen sont gros, lourds et ne peuvent pas être emportés par le vent. C'est généralement des hyménoptères qui se chargent de la pollinisation. En France, l'abeille européenne et les bourdons sont les pollinisateurs les plus fréquents. Certains plants sont autofertiles mais d'autres comme la variété Constance Eliot, ne le sont pas.

Le moment le plus propice à la pollinisation se trouve lorsque les stigmates sont au niveau des anthères. À ce moment, les insectes en allant récolter le nectar (ou le pollen) abondamment fourni par la fleur se frottent aux stigmates qui à cet instant secrètent un liquide visqueux capable de capter le pollen éventuellement transporté par l'insecte.

Écologie

Passiflora caerulea est originaire d'une zone couvrant le Brésil, l'Argentine, le Paraguay et l'Uruguay.

Elle est cultivée comme ornementale dans les régions tempérées.

Elle s'est naturalisée et est même devenue envahissante dans certaines régions du monde, comme en Espagne5, en Californie, Hawaï et Nouvelle-Zélande6.

Composition

On sait que les membres du genre Passiflora contiennent des alcaloïdes, phénols, glucosides de flavonoïdes et des composés cyanogènes7. Des alcaloïdes de type harmane n'ont pas été trouvés dans P. caerulea.

Dans la fleur de Passiflora caerulea il a été isolé une flavone8, la chrysine, connue ou du moins vendue aux sportifs comme inhibiteur de l'aromatase (bien que des études in vivo n'aient montré aucune d'activité inhibitrice de l'aromatase9,10).

La plante fraiche écrasée libère rapidement une quantité importante de cyanure (30-40 μmol/g). Il a été isolé des glucosides cyanogènes : la gynocardine, un mélange épimère de sulfate de tétraphylline B et de sulfate d'épitétraphylline B11.

Le catabolisme normal des hétérosides cyanogènes conduit à la libération d'acide cyanhydrique qui est aussitôt converti en asparagine12.

...through some moderate overcast, 5 second single exposure... note the star trails! It will be closest on 7/29/20. Next visit in 6700 years. The green color is from ionized cyanogen. Little Compton, RI, USA

[Comet C/2022 E3 ZTF]

___________________________________________________________

It was very hard to find him and in the end I did it with just 70mm on my camera and lens. Quite a challenge for sure. I now not perfect but for 70mm not to bad :-)

___________________________________________________________

31/01/2023

___________________________________________________________

From Wikipedia, the free encyclopedia

C/2022 E3 (ZTF)

C2022 E3 (ZTF)- Alessandro Bianconi.png

C/2022 E3 (ZTF) on 27 January 2023.

Discovery

Discovered byZwicky Transient Facility

Discovery date2 March 2022[1]

Orbital characteristics

Observation arc456 days

Number of

observations3382

Orbit typeLong-period comet

Aphelion≈2800 AU (barycentric epoch 1950)[2]

Perihelion1.112 AU[3]

Eccentricity1.00002 (heliocentric epoch 2495)[4]

0.999992 (barycentric epoch 2050)[2]

Orbital period≈50,000 yr (inbound)[2]

Ejection or many millions of years (outbound)

Inclination109.17°

Last perihelion12 January 2023[3]

Earth MOID0.221 AU (33.1 million km)[3]

Jupiter MOID1.743 AU (260.7 million km)

Physical characteristics

Comet total

magnitude (M1)10.5±0.6[3]

C/2022 E3 (ZTF) is a long-period comet from the Oort cloud that was discovered by the Zwicky Transient Facility (ZTF) on 2 March 2022.[1] The comet has a bright green glow around its nucleus, due to the effect of sunlight on diatomic carbon and cyanogen.[6][5]

The comet's systematic designation starts with C to indicate that it is not a periodic comet, and "2022 E3" means that it was the third comet to be discovered in the first half of March 2022.[5]

The comet nucleus was estimated to be about a kilometre in size, rotating every 8.7 hours.[7][8] Its tails of dust and gas extended for millions of kilometres and, during January 2022, a third anti-tail was visible.[9]

The comet reached its perihelion on 12 January 2023, at a distance of 1.11 AU (166 million km; 103 million mi), and the closest approach to Earth was on 1 February 2023, at a distance of 0.28 AU (42 million km; 26 million mi). The comet reached magnitude 5 and is visible with the naked eye under moonless dark skies.[10][11][12][13] (Wikipedia)

___________________________________________________________

Mount: Sky Watcher “Star Adventure 2i”

Guiding: N/A

Filter: N/A

Camera: Canon EOS R7 (None modified)

Canon EF 70-200mm L USM f2.8 IS

Focal length: 70mm

228frames - ISO 1000 - f3.5 - 30 second shutter speed each photo

Darks: 15 frames

Flats: 15 frames

Bios: 15 frames

DarkFlats: N/A

Bortle 5.5

Processing: AstroPixelProcessor > Photoshop >Topaz > Photoshop

C/2022 E3 (ZTF) is a long period comet from the Oort cloud that was discovered by the Zwicky Transient Facility on 2 March 2022. The comet has a bright green glow around its nucleus which is due to the effect of sunlight on its molecules, especially diatomic carbon and cyanogen. Wikipedia

Not a naked eye comet here with dark skies, nice in binoculars as well and a really nice sight in my Meade LX-90 (8") telescope.

Single shot.

Canon5Dmark3, 3.2 sec., f/5.6, ISO 25600

C/2022 E3 (ZTF) is a long period comet from the Oort cloud that was discovered by the Zwicky Transient Facility on 2 March 2022. The comet has a bright green glow around its nucleus which is due to the effect of sunlight on its molecules, especially diatomic carbon and cyanogen.

The comet reached its perihelion on 12 January 2023, at a distance of 1.11 AU (166 million km; 103 million mi), and the closest approach to Earth will be on 1 February 2023, at a distance of 0.28 AU (42 million km; 26 million mi). The comet exceeded magnitude 6 and is dimly visible with the naked eye as a small diffuse smudge under a dark enough sky, but most viewers will need an instrument such as binoculars. A magnitude 5 star is easier to see than a magnitude 5 comet because the comet has a low surface brightness and we see the same total amount of light from the comet as we would from a star with the same magnitude. The first quarter moon occurred on 28 January and will further obscure viewing the comet without optical aid.

EQ6R Pro

William optics GT81 and reducer

2600mc cooled to 0c

ASIAIR Pro

Optolong L Pro

ZWO EAF

71 x 180s exposures plus calibration frames

[Wikipedia:]

C/2022 E3 (ZTF) est une comète à longue période qui a été découverte par le Zwicky Transient Facility le 2 mars 2022. Elle a atteint son périhélie le 12 janvier 2023, à une distance de 1,11 ua, et sera au plus près de la Terre le 1er février 2023, à une distance de 0,28 ua.

C/2022 E3 (ZTF) is a long-period comet from the Oort cloud that was discovered by the Zwicky Transient Facility on 2 March 2022.[1] The comet has a bright green glow around its nucleus, which is due to the effect of sunlight on its molecules, especially diatomic carbon and cyanogen.

Acquisition:

Rising Cam IMX571 color + Zenithstar

iOptron CEM26 + iPolar

Filtre Optolong L-Pro

ZWO ASI224MC + WO Uniguide 120mm

Astro Photography Tool (APT) & PHD2

28 x 2min -- Gain 101 -- Offset 245

Traitement/processing :

SIRIL & Gimp

Video made with the 28 images, where you can see the movment of the comet : youtu.be/LTVSyVoIvow

AstroM1

About this image:

Comet C/2021 A1 Leonard imaged on 28 December 2021 from South Africa.

I tried to capture as much detail in the structure of the tail as possible, which makes processing a challenge (as the comet is moving). The coma, tail and stars were processed individually, and each part aligned, stacked and combined.

The Comet has a green Coma (or head). The green colour is caused by Cyanogen (CN) and diatomic Carbon (C2), which glows in the green part of the Electromagnetic Spectrum of Light when illuminated by the Sun in space.

Technical Info:

Lights/Subs total integration time: 80 min.

2 Panels (40 min. per panel).

L-Pro = 16 x 90 sec. (per panel).

R = 10 x 30 sec. (per panel).

G = 10 x 30 sec. (per panel).

B = 10 x 30 sec. (per panel).

Dual Telescope Set-up:

William Optics Star 71 Imaging APO 350mm f/4.9 &

William Optics SpaceCat 51 APO 250mm f/4.9 - Limited Edition.

QHY163M Camera sensor cooled to -15°C.

Calibration frames: Bias, Darks and Flats.

SGP Mosaic and Framing Wizard.

PlaneWave PlateSolve 2 via SGP.

Pre-Processing and Linear workflow in PixInsight. Straton was used for star separation, and final processing was done in Photoshop.

Astrometry Info:

Center RA, Dec: 323.505, -34.040

Center RA, hms: 21h 34m 01.210s

Center Dec, dms: -34° 02' 24.584"

Size: 7.56 x 2.88 deg.

Radius: 4.046 deg.

Pixel scale: 16.2 arcsec/pixel.

Orientation: Up is 2.18 degrees E of N.

View an Annotated Sky Chart for this image.

Carl Sagan on Comets:

youtu.be/1hlONoWw39M

People's reaction to Comets in History:

Excerpt from Cosmos S01E04: "By 1910, Halley's comet returned once more. But this time, astronomers using a new tool, the spectroscope had discovered cyanogen gas in the tail of a comet. Now, cyanogen is a poison. The Earth was to pass through this poisonous tail. The fact that the gas was astonishingly, fabulously thin reassured almost nobody. For example, look at the headlines in the Los Angeles Examiner for May 9, 1910: "Say, Has That Comet 'Cyanogened' You Yet?" "Entire Human Race Due For Free Gaseous Bath. Expect High Jinks." Or take this from the San Francisco Chronicle, May 15, 1910: "Comet Comes And Husband Reforms." "Comet Parties Now Fad In New York." Amazing stuff! In 1910, people were holding comet parties, not so much to celebrate the end of the world as to make merry before it happened. There were entrepreneurs who were hawking comet pills. I think I'm gonna take one for later. And there were those who were selling gas masks to protect against the cyanogen. And comet nuttiness didn't stop in 1910." - Carl Sagan, Cosmos.

Flickr Explore:

2021-12-30

This image is part of the Legacy Series.

Photo usage and Copyright:

Medium-resolution photograph licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Terms (CC BY-NC-ND 4.0). For High-resolution Royalty Free (RF) licensing, contact me via my site: Contact.

Martin

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Here is my photograph of Comet C/2022 E3 (ZTF) aka “The Green Comet” which I captured on January 30, 2023—a soul-crushinginly cold night with temperatures around -25°C—in the Skull Valley desert, Utah, United States. With so many cloudy nights this winter, I thought I would miss this one. But circumstance gave me one good opportunity as long as I was willing to brave the cold. Did you know that touching metal after hours outside at these temperatures enables it to somehow “burn”?

This image was created using 175 separate 30-second exposures (longer and the comet actually streaks relative to the stars due to its movement), combining of the comet image separately from the stars, and then re-combining the two. As a bonus, you can multiple galaxies in the image.

Comet C/2022 E3 (ZTF), called the “green comet” in various news coverage, is visible in the night sky right now, although less impressive than 2020’s Comet Neowise.

ZTF will be hard to see under moonlight with heavy light pollution, but easier to see with no moon and binoculars. With little light pollution it is much easier to see. (Apparently it was quite striking to see when my mom checked it out under her crazy-dark Wyoming skies!) This comet’s “near pass”—the closest point in its orbit to the earth—was on February 2nd. While still visible, it is now traveling farther away from earth, growing fainter day-by-day. If it survives its journey, it will return again in around 50,000 years. Something for the kiddos to look forward to!

Comet C/2022 E3 (ZTF), at the time these photos were captured, featured two prominent ‘tails’:

The blue-tinted tail (extending frame right) is the ion tail, which is created by ultraviolet radiation ejecting electrons off particles in the coma (a cloud of gases surrounding the comet’s nucleus). The appearance of the ion tail can change rapidly (e.g. even between short exposures) due to interplay with and fluctuation of the solar wind (a continuous flow of charged particles ejected from the sun).

The warmer, fainter, larger “tail” is the dust tail, formed by solar radiation vaporizing volatile compounds in the comet, which stream out and carry dust with them. This reflects sunlight directly.

How do you end up with the name “Comet C/2022 E3 (ZTF)”? Breaking it down, “C” represents a non-periodic comet: it takes more than 200 years to orbit the sun. It was discovered in 2022. “E3” represents the time period of discovery, with “E” represents the fifth half-month of the year, and “3” representing the third comet discovered in that half-month. “ZTF” stands for who discovered it! In this case, the Zwicky Transient Facility, which is a wide-field sky astronomical survey running through the Samuel Oschin Telescope at the Palomar Observatory in California. What about 2020’s “NEOWISE”? In that case, it was discovered by NASA’s Near-Earth Object Wide-field Infrared Survey Explorer.

Why are articles calling this “The Green Comet”? Mainly, I expect, because very cool or very terrifying things love to have a name of some sort in media coverage, and “The Green Comet” got to stick. “ZTF” is not so catchy, to be fair. Comets typically present with a clear blue-green glow around the nucleus. It is rather prominent on this comet, relative to other signal, but not a unique characteristic of this comet. So why this color? Sources frequently cite that this color comes from Cyanogen (CN) in the comet, but this is not correct. As best I can determine, the most likely explained by a combination of “Swan Bands” of Carbon (C2) emissions—which is to say, some blending of prominent light emissions is responsible for the color we observe. This was probably discussed in early interviews and got to stick.

Edited in PixInsight and Adobe Photoshop. For full details on post-processing, reference the link at AstroBin or the processing notes in this text document:

tinyurl.com/JP2022ZTF

[Wikipedia:]

C/2022 E3 (ZTF) est une comète à longue période qui a été découverte par le Zwicky Transient Facility le 2 mars 2022. Elle a atteint son périhélie le 12 janvier 2023, à une distance de 1,11 ua, et sera au plus près de la Terre le 1er février 2023, à une distance de 0,28 ua.

C/2022 E3 (ZTF) is a long-period comet from the Oort cloud that was discovered by the Zwicky Transient Facility on 2 March 2022.[1] The comet has a bright green glow around its nucleus, which is due to the effect of sunlight on its molecules, especially diatomic carbon and cyanogen.

Acquisition:

Rising Cam IMX571 color + Zenithstar

iOptron CEM26 + iPolar

Filtre Optolong L-Pro

ZWO ASI224MC + WO Uniguide 120mm

Astro Photography Tool (APT) & PHD2

28 x 2min -- Gain 101 -- Offset 245

Traitement/processing :

DSS & Gimp

Video made with the 28 images, where you can see the movment of the comet : youtu.be/LTVSyVoIvow

youtu.be/WpzOfmu_Nqo

AstroM1

C/2022 E3 (ZTF) is a long-period comet from the Oort cloud that was discovered by the Zwicky Transient Facility (ZTF) on 2 March 2022. The comet has a bright green glow around its nucleus, due to the effect of sunlight on diatomic carbon and cyanogen. The comet won't be seen again for approximately 50,000 years.

This was a bit of an experiment and taken with equipment that I have not used before for astrophotography. The mount is a 23 year old Meade LXD55 which is of low quality, but I have had it sitting around for many years, and while good for visual, have never used it for astrophotography. I wanted to try and set this up as a portable rig, so spent a few clear nights before capturing this image ironing out all the issues. I had to go an buy a new guide scope, as I have previously sold my spare one a few years ago. (I don't like having to re-buy items which I have previously sold). After getting everything tested, and a few false starts due to getting clouded out, it was time to image. I was able to successfully polar align, arrive at the co-ordinates of the comet, and image for 38 minutes before the batteries in both the laptop, and camera (canon 600d) went flat. Once I replace the camera battery, and mains powered the laptop, the comet set behind the roof of the house and out of sight of the telescope. The main reason for using this setup, was to see that it could work. I was happy with the result

This image was taken using 76 x 30 second exposures in color with the Canon 600d, Stacking and processing was done in PixInsight.

Equipment Details:

•Skywatcher 80ED F7.5 600mm focal length

•Meade LXD55 Mount with Autostar 497 controller

•Canon 600d unmodified CMOS Camera

•ZWO EAF Automatic focuser

•Orion Mini Guide Scope

•ZWO ASI120mc Guide Camera

•Astrophotography Tool Software for full automation

Exposure Details:

73 x 30 seconds

Total Integration Time: 38 Minutes.

C/2022 E3 (ZTF) is a long-period comet from the Oort cloud that was discovered by the Zwicky Transient Facility on 2 March 2022. The object was initially identified as an asteroid, but subsequent observations revealed it had a very condensed coma, indicating it is a comet. The comet has a bright green glow around its nucleus, which is due to the effect of sunlight on its molecules, especially diatomic carbon and cyanogen. The comet's closest approach to Earth was on 1 February 2023, at a distance of 0.28 AU (42 million km; 26 million mi). The comet reached magnitude 5 and is visible with the naked eye under moonless dark skies.

An old friend of ESA, Comet 46P/Wirtanen, is crossing our skies this month.

The comet nucleus is at the core of the brightest spot at the centre of the image, and the green diffuse cloud is its coma. The green colour is caused by molecules – mainly CN (cyanogen) and C2 (diatomic carbon) – that are ionised by sunlight as the comet approaches the Sun. A hint of the comet’s tail is visible to the upper left; the diagonal stripes are star trails.

A bright comet with a period of 5.5 years, 46P had been chosen in the 1990s as the target of ESA’s Rosetta mission. However, a launch delay from 2003 to 2004 meant the spacecraft would not be able to rendezvous with that comet at its closest approach to the Sun in 2013, prompting the Rosetta team to select a new target, the now famed 67P/Churyumov-–Gerasimenko.

Comet 46P was at perihelion, the closest point to the Sun along its orbit, on 12 December, and kept moving towards our planet, reaching the closest distance to Earth on 16 December.

Astronomers across the world – professional, student and amateur alike – have been observing the comet recently, and will keep doing so in coming weeks as it moves away from the Sun along its orbit.

This image was taken by Wouter Van Reeven at ESA’s European Space Astronomy Centre (ESAC) near Madrid, Spain, on 14 December 2018. It is a composite of 132 individual images, each with a 10 second exposure, using a William Optics ZS 71 ED (71 mm refractor) telescope and a Canon EOS 700D DSLR camera (ISO: 3200). The field of view spans 2.8 degrees x 1.8 degrees.

More information: December comet brings back Rosetta memories

Credits: ESA / ESAC Astronomy Club / W. Van Reeven

Today, I rooted my phone and installed the Cyanogen modded rom (version 4.22 4.23 just came out, flashing now) on my mytouch3g (mt3g/htc magic/google ion). It's sorta like jailbreaking your apple iphone, but taking it a step further with an entirely unlocked operating system allowing you to do anything and everything with the phone. A few things I really like are the improved speeds, multi-touch enabled, rotated horizontal home screen, and wifi tethering (using the phone as an internet hotspot on the go).

The very green Comet Wirtanen (at far upper right) to the west of the rising Orion the Hunter (at far left), over a snowy winter scene. This was December 6, 2018 with the comet in Eridanus and heading north into Taurus. It was a very clear night but crisp at -15° C. But it was a dry cold!

The characteristic green colour of comets comes from glowing cyanogen and diatomic carbon molecules. The comet was easy in 45mm binoculars and was barely naked eye if you knew exactly where to look and used averted imagination!

This is a wide view with the 35mm lens Canon lens on the Canon 6D MkII, at f/2.8 and is a stack of 3 x 1-minute exposures for the sky, tracked on the Star Adventurer Mini, blended with a stack of 3 x 1-minute exposures for the ground, untracked to preserve details. However, the blurring of the trees from the tracked images is tough to mask out without introducing back the trailed stars. So I have left it in as a soft background and drop-shadow effect.

Quick go at C/2022 E3 ZTF from last night, didn't get chance to do too much on this as had to be in work early, but as it's not been here since the Stone Age thought I should give it a bash :)

C/2022 E3 (ZTF) is a long period comet from the Oort cloud that was discovered by the Zwicky Transient Facility on 2 March 2022. The comet has a bright green glow around its nucleus, which is due to the effect of sunlight on its molecules, especially diatomic carbon and cyanogen.

Aphelion: ≈2800 AU (barycentric epoch 1950)

Discovered by: Zwicky Transient Facility

Discovery date: 2 March 2022

Observation arc: 298 days

Sorbus commixta is arguably one of the very best Mountain Ash trees for autumn colour. The mid-green, pinnate foliage turns vivid red and orange in the autumn and orange-red berries are produced in large clusters. These berries are popular with birds throughout the winter and provide an additional element of seasonal interest. Corymbs of fluffy white flowers appear in May-June and are very popular with bees and other pollinating insects.

This small erect Japanese Rowan tree will grow to 6 x 4 metres in 20 years so is ideal for limited spaces. It is very tough Rowan tree that tolerates an exposed position and suits full or part sun. It will grow in most soils, although it is happiest in a slightly acidic soil.

Physical Characteristics:

Sorbus commixta is a deciduous Tree growing to 10 m (32ft) by 6 m (19ft).

See above for USDA hardiness. It is hardy to UK zone 6 and is not frost tender. It is in flower in May, and the seeds ripen in September. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects.

Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil. The plant can tolerates strong winds but not maritime exposure.

It can tolerate atmospheric pollution.

Edible Uses:

Fruit - raw or cooked. About 7.5mm across, it is produced in fairly large bunches making harvesting easy. Leaves - cooked. A famine food when all else fails. The leaves may contain cyanogens so caution is advised.

The seeds probably contain hydrogen cyanide. This is the ingredient that gives almonds their characteristic flavour. Unless the seed is very bitter it should be perfectly safe in reasonable quantities. In small quantities, hydrogen cyanide has been shown to stimulate respiration and improve digestion, it is also claimed to be of benefit in the treatment of cancer. In excess, however, it can cause respiratory failure and even death.

Imaging telescopes or lenses: Hand made 10" F/3.25

Imaging cameras: Canon 600Da

Mounts: Sky-Watcher EQ6 Pro Belt mod

Guiding telescopes or lenses: Deep Sky Instruments 180mm guider

Guiding cameras: QHYCCD QHY5II-L

Software: IRIS software IRIS 5.59, Ionov Ivan FitStacker 11, Cyanogen Maxim DL 6 Pro

Accessories: Televue Paracor Type II

RA center: 56.797 degrees

DEC center: 24.127 degrees

Pixel scale: 2.069 arcsec/pixel

Orientation: -178.520 degrees

Field radius: 0.828 degrees

Comet C/2022 E3 (ZTF)

2023-01-29

Nikon D5300

Nikkor 55-200mm (200mm)

EXIF: f/5.6 ISO8000

95x8s (12.6min)

22xdarks

Stacked/Apilado: DeepSkyStacker

Edited/Editado: Lightroom

C/2022 E3 (ZTF) is a long period comet from the Oort cloud that was discovered by the Zwicky Transient Facility on 2 March 2022. The comet has a bright green glow due to the presence of diatomic carbon and cyanogen.

The comet reached its perihelion on 12 January 2023, at a distance of 1.11 AU, and the closest approach to Earth was on 1 February 2023, at a distance of 0.28.

C/2022 E3 (ZTF) es un cometa de período largo proveniente de la nube de Oort que fue descubierto por el proyecto Zwicky Transient Facility el 2 de marzo de 2022. Este cometa tiene un brillo de color verde debido a la presencia de carbono diatómico y cianógeno.G

El cometa alcanzó su perihelio el 12 de enero de 2023, a una distancia de 1.11UA y su aproximación más cercana a la Tierra fué el 1 de febrero de 2023, a una distancia de 0.28UA.

Observatori de Pujalt, Catalunya, España

The very green Comet Wirtanen (aka 46P) appears above a snowy backyard scene – my backyard! – on December 3, 2018, as it climbs higher in the sky each night through Cetus into Eridanus in early December 2018 at this very favourable and close return.

The comet was an obvious diffuse glow in any binoculars but to the camera appeared very green or cyan, as comets often do, from glowing cyanogen and diatomic carbon molecules in its coma.

This is a stack of 6 x 30-second exposures with the 35mm Canon lens at f/2 and Canon 6D MkII at ISO 1600, with the camera on a Star Adventurer Mini tracker. A single exposure was blended in just for the ground to keep the bushes and foreground sharper.

Comet 46P/Wirtanen close to the Pleiades (M45) on 16 December 2018 (imaged from Southern Africa, after a thunder shower and in between clear gaps in partly cloudy conditions).

I kept the exposures a bit shorter than I would have liked, and rather pushed the ISO a bit higher due to the cloud cover that was increasing. Luckily it was clear towards the North for just long enough to take the series of photos required for stacking, and despite the weather, the Astronomical Seeing was actually really excellent after the rain.

The Comet's faint tail was only visible in darker skies with longer exposures. This Comet has a beautiful bright green Coma (or head). The green color is caused by Cyanogen (CN) and diatomic Carbon (C2), which glows in the green part of the Electromagnetic Spectrum of Light when illuminated by the Sun in space.

Geocentric Distance:

0.0775 AU (Astronomical Unit).

30 Lunar distances.

11.5 Million km.

7.1 Million miles.

Gear:

Nikon AF-S NIKKOR 200-500mm f/5.6E ED VR Lens.

Celestron AdvancedVX Telescope Mount.

Optolong L-Pro Clip-In Filter for Nikon.

Nikon D750 DSLR.

Lights/Subs:

46 x 60 sec. ISO 3200 exposures.

Calibration Frames:

30 x Bias

20 x Darks

Astrometry Info:

Center RA, Dec: 58.071, 22.397

Center RA, hms: 03h 52m 17.067s

Center Dec, dms: +22° 23' 47.549"

Size: 8.45 x 5.68 deg

Radius: 5.089 deg

Pixel scale: 19 arcsec/pixel

Orientation: Up is 130 degrees E of N

View an Annotated Sky Chart for this image.

View this image in the WorldWideTelescope.

Processing:

Pre-Processing and Linear workflow in PixInsight,

and finished in Photoshop.

Carl Sagan on Comets:

youtu.be/1hlONoWw39M

People's reaction to Comets, excerpt from Cosmos S01E04:

Time code: 13:18

"By 1910, Halley's comet returned once more. But this time, astronomers using a new tool, the spectroscope had discovered cyanogen gas in the tail of a comet. Now, cyanogen is a poison. The Earth was to pass through this poisonous tail. The fact that the gas was astonishingly, fabulously thin reassured almost nobody. For example, look at the headlines in the Los Angeles Examiner for May 9, 1910: "Say, Has That Comet 'Cyanogened' You Yet?" "Entire Human Race Due For Free Gaseous Bath. Expect High Jinks." Or take this from the San Francisco Chronicle, May 15, 1910: "Comet Comes And Husband Reforms." "Comet Parties Now Fad In New York." Amazing stuff! In 1910, people were holding comet parties, not so much to celebrate the end of the world as to make merry before it happened. There were entrepreneurs who were hawking comet pills. I think I'm gonna take one for later. And there were those who were selling gas masks to protect against the cyanogen. And comet nuttiness didn't stop in 1910." - Carl Sagan, Cosmos.

This image is part of the Legacy Series.

Flickr Explore:

2018-12-19

Photo usage and Copyright:

Medium-resolution photograph licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Terms (CC BY-NC-ND 4.0). For High-resolution Royalty Free (RF) licensing, contact me via my site: Contact.

Martin

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Galaxia del Escultor

Telescopio T305 mm Riccardi-Honders Astrograph.

Cámara FLI PL29050 (CCD)

Montura Equatorial Astro Physics AP 1200 GTO

Cámara guiado Starlight Express Lodestar

Software de captura MaxIm DL (Cyanogen)

Procesado con Pixinsight

5R - 6G - 5B de 360 sg a bin x1

9L de 10m a bin x1

Hacienda los Andes, Chile.

20-08-2017 y 21-08-17

Imaging telescope: TS APO80

Imaging camera: QSI 660wsg-8

Mount: Orion HDX110 EQ-G

Software: Cyanogen Maxim DL 6 Pro, Pixinsight 1.8

Astrodon Ha 5nm: 23x900"

Astrodon LRGB: 70x300"

Integration: 11.6 hours

From the city center of Tbilisi, Georgia

31x900" sec of Ha, OIII and SII narrowband, 7.8 hours total

Imaging: TS APO80 with QSI 660wsg-8 camera

Software used: Pixinsight 1.8, Cyanogen Maxim DL 6 Pro

This was taken on 16th January 2015 at my local dark spot Turf Hill

Guided on the stars for 2 min subs, i grabbed 36 mins worth, really think i should have guided on the actual comet tho to grab a more dramatic tail.

Not sure when ill try another comet, not really my cup of tea....they are buggers to process

I used my usual gear to capture this....

SW 130-pds

HEQ5

Canon 7D

Stacked in DSS and process in Pixinsight & Photoshop

Here is some info about Lovejoy...

C/2014 Q2 (Lovejoy) is a long-period comet discovered on 17 August 2014 by Terry Lovejoy using a 0.2-meter (8 in) Schmidt–Cassegrain telescope.[2] It was discovered at apparent magnitude 15 in the southern constellation of Puppis.[2] It is the fifth comet discovered by Terry Lovejoy. Its blue-green color is the result of cyanogen and diatomic carbon being burned off the comet as it passes through space.

By December 2014, the comet had brightened to roughly magnitude 7.4,[5] making it a small telescope and binoculars target. By mid-December, the comet was visible to the naked eye for experienced observers with dark skies and keen eyesight.[6] On 28−29 December 2014, the comet passed 1/3° from globular cluster Messier 79.[7] In January 2015, it brightened to roughly magnitude 4,[8] and became one of the brightest comets located high in a dark sky in years. On 7 January 2015, the comet passed 0.469 AU (70,200,000 km; 43,600,000 mi) from Earth.[9] It crossed the celestial equator on 9 January 2015 becoming better seen from the northern hemisphere.[10] The comet came to perihelion (closest approach to the Sun) on 30 January 2015 at a distance of 1.29 AU (193,000,000 km; 120,000,000 mi) from the Sun.[3]

Before entering the planetary region (epoch 1950), C/2014 Q2 had an orbital period of about 11000 years.[4] After leaving the planetary region (epoch 2050), it will have an orbital period of about 8000 years.

Canon EOS6D with Leica Elmarit-R 180

Shot on Sunday, 2020/7/19 ca. 22:20 CEDT in Darmstadt, Germany

The comet is a lot dimmer now than when I last observed it on the morning Friday, 10 July, although the sky was much darker now. The colour of the coma has clearly changed from yellow to green, which is indicative of a change in the outgassed materials dominating the coma from sodium to cyanogen (CN)2 and/or diatomic carbon C2.

On January 20, 2023, comet C/2022 E3 (ZTF) was visible, though faint (Mag: 9.44), in the night sky, and was located in the constellation of Boötes (RA 15h 33m 54s Dec +50° 47′ 12"), close to the borders of Draco and Ursa Minor, moving towards being circumpolar for many northern latitudes. Not related but this is close to the radiant point of the Quadrantids meteor shower. According to BBC Sky at Night Magazine, it was visible as a binocular object at this time. At this time it was 167.55. Gm from the Sun and 72.32 Gm from the Earth.

Comet C/2022 E3 (ZTF) also known as the "green comet", was discovered by the Zwicky Transient Facility on March 2, 2022, and it reached perihelion, its closest point to the Sun, on January 12, 2023. The comet made its closest approach to Earth on February 1, 2023, at a distance of 43.5 Gm.

C/2022 E3 (ZTF) is a non-periodic comet from the Oort cloud. The comet has a bright green glow around its nucleus, due to the effect of sunlight on diatomic carbon and cyanogen. The comet's systematic designation starts with C to indicate that it is not a periodic comet, and "2022 E3" means that it was the third comet to be discovered in the first half of March 2022.

The comet nucleus was estimated to be about a kilometre in size, rotating every 8.5 to 8.7 hours. Its tails of dust and gas extended for millions of kilometres and, during January 2023, an anti-tail was also visible.

The comet reached its perihelion on 12 January 2023, at a distance of 1.11 AU (166 million km; 103 million mi), and the closest approach to Earth was on 1 February 2023, at a distance of 0.28 AU (42 Gm). The comet reached magnitude 5 and was visible with the naked eye under moonless dark skies. None of the stars seen here can be seen with the naked eye as this is a sparsely populated area in the northern part of Boötes.

Boötes, also known as "The Herdsman," is a large northern constellation containing the bright star Arcturus, and is shaped like a kite or ice-cream cone. It's easily found by "arching" from the handle of the Plough in Ursa Major. Boötes is a Latin name, and the pronunciation is "boo-OH-tees". The Greek word it comes from means "herdsman" or "ox-driver". Boötes is located in the northern sky, near Ursa Major (the Great Bear) and is best seen in the spring and summer. It's a large constellation, extending about 51 degrees across the sky. Arcturus is the brightest star in Boötes, and the fourth brightest star in the night sky.

Jargon Buster:

Mag; Apparent magnitude is a measure of the brightness of a star.

RA; right ascension is the celestial equivalent of longitude, measuring the angular distance eastward along the celestial equator from the vernal equinox to a celestial object's hour circle, and is typically expressed in hours, minutes, and seconds.

Dec; declination is the celestial equivalent of latitude on the celestial sphere in the equatorial coordinate system.

Radiant point; The "radiant point" of a meteor shower is the celestial point in the sky from which the meteors appear to originate, and the paths of meteors in a shower appear to converge at this point.

Non-periodic comets; Also known as long-period comets, are those with orbital periods exceeding 200 years, often seen only once as they pass through the solar system on near-parabolic or hyperbolic orbits, potentially originating from the Oort cloud.

Oort cloud; A theoretical, vast, spherical shell of icy bodies, thought to be the source of long-period comets, that surrounds our solar system at distances far beyond the Kuiper Belt.

Perihelion; The point in the orbit of a planet, asteroid or comet that is nearest to the sun. It is the opposite of aphelion, which is the point farthest from the sun.

GM; A gigametre is a unit of length in the International System of Units (SI) representing a distance of 1 billion meters or 1 million kilometres.

Diatomic; Are molecules composed of only two atoms, of the same or different chemical elements.

AU; The astronomical unit is a unit of length defined to be exactly equal to 149597870700 m. Historically, the astronomical unit was conceived as the average Earth-Sun distance (the average of Earth's aphelion and perihelion), before its modern redefinition in 2012.

en.wikipedia.org/wiki/C/2022_E3_(ZTF)

en.wikipedia.org/wiki/Bo%C3%B6tes

The Green Comet .

Comet c/2022 E3 ZTF a few days after perihelion ( nearest approach to the sun on Jan 12th )and as it was heading closer to Earth at 2.967 km/s 😮. The nucleus is about a km wide and the bright green glow around it comes from diatomic carbon and cyanogen.

1 hour of 60 seconds shots LRGB from County Durham . It was amazing how much the structure in the Ion tail changed minute by minute . Skywatcher Esprit 100. Zwo 1600 mono. Baader LRGB filters Zwo mini autoguider and Asi Air pro plus . Heq5 oro mount.

2023-01-21

Nikon D5300

Nikkor 55-200mm (135mm)

EXIF: f/5 ISO1200

29x8s (3.8min)

10xdarks

Stacked/Apilado: Sequator

Edited/Editado: Lightroom

C/2022 E3 (ZTF) is a long period comet from the Oort cloud that was discovered by the Zwicky Transient Facility on 2 March 2022. The comet has a bright green glow due to the presence of diatomic carbon and cyanogen.

The comet reached its perihelion on 12 January 2023, at a distance of 1.11 AU, and the closest approach to Earth was on 1 February 2023, at a distance of 0.28.

C/2022 E3 (ZTF) es un cometa de período largo proveniente de la nube de Oort que fue descubierto por el proyecto Zwicky Transient Facility el 2 de marzo de 2022. Este cometa tiene un brillo de color verde debido a la presencia de carbono diatómico y cianógeno.G

El cometa alcanzó su perihelio el 12 de enero de 2023, a una distancia de 1.11UA y su aproximación más cercana a la Tierra fué el 1 de febrero de 2023, a una distancia de 0.28UA.

Sant Mateu de Bages,

Catalunya, España

A quick wide-field capture of something interesting that one doesn't have the opportunity to see often. Comet C/2016 M1 (PANSTARRS), passing between the constellation Norma and Ara (close to the Open Star Cluster NGC 6152) at 01:00 on 15 July 2018.

The Comet doesn't have much of a tail at the moment, but has a beautiful green coma. The green color is caused by Cyanogen (CN) and diatomic Carbon (C2), which glows green when illuminated by the Sun in space.

Click on the image to zoom in a bit LARGER.

Gear:

William Optics Star 71mm f/4.9 Imaging APO Refractor Telescope.

William Optics 50mm Finder Scope.

Celestron SkySync GPS Accessory.

Orion Mini 50mm Guide Scope.

Orion StarShoot Autoguider.

Celestron AVX Mount.

QHYCCD PoleMaster.

Celestron StarSense.

MBox USB Meteostation.

RoboFocus RF3 Focuser.

Optolong L-Pro & RGB filters.

QHYCFW2-M-US Filterwheel (7 position x 36mm).

QHY163M Cooled CMOS Monochrome Astronomy Camera.

Tech:

Guiding in Open PHD 2.6.5.

Image acquisition in Sequence Generator Pro.

Camera Settings:

QHY Sensor Sensitivity:

Gain: 120

Offset: 35

Imaged at -20°C

LRGB:

L = 10 x 30 sec.

R = 10 x 30 sec.

G = 10 x 30 sec.

B = 10 x 30 sec.

Processing:

Pre-Processing and Linear workflow in PixInsight,

and finished in Photoshop.

Astrometry info:

View an Annotated Sky Chart for this image.

Center RA, Dec: 248.960, -52.563

Center RA, hms: 16h 35m 50.336s

Center Dec, dms: -52° 33' 45.078"

Size: 2.93 x 2.22 deg

Radius: 1.837 deg

Pixel scale: 6.59 arcsec/pixel

Orientation: Up is 90.5 degrees E of N

View this image in the World Wide Telescope.

SQM-L Sky Quality Reading:

20.5

About the Milky Way, and Earth's place within it:

The Milky Way Galaxy is estimated to have over 400 billion stars. Stars are suns, and just like in our Solar System, many of the stars have planets with moons orbiting them. Our sun is a middle aged Yellow Dwarf star, located in the Orion Arm (or Orion Spur) of the Milky Way Galaxy. It’s a minor side spiral arm, located between two larger arms of the Milky Way Galaxy's spiral. The Milky Way is merely one mid-sized barred spiral Galaxy, amongst over 100 billion other Galaxies in the observable Universe. When we look up at the night sky from Earth, we see a glimpse of the Carina-Sagittarius Arm of the Milky Way Galaxy. It takes about 250 million years for the Milky Way Galaxy's spiral arms to complete one rotation.

The size, distance and age of the Universe is far beyond human comprehension. The known Universe is estimated to contain over One Billion Trillion stars.

1 000 000 000 000 000 000 000

Flickr Explore:

2018-07-16

Martin

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[Home Page] [Photography Showcase] [Flickr Profile]

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Comet NEOWISE captured on 20th July at 22.44 UT from Kent, UK. Notice that the coma of the comet is now displaying a green/cyan colour due to the stimulation of cyanide/cyanogen and diatomic carbon. Sony A7RII, cropped FE 24-105 (@105mm), 15x 30sec (7.5 minutes in total), ISO1600.

The Comet Leonard was discovered in January 2021 by Gregory Leonard of the University of Arizona’s Mount Lemmon Sky Center’s Santa Catalina Infrared Observatory near Tucson, AZ using its 1.5 meter (60 inch) diameter telescope. Comet Leonard was at its brightest as viewed from Earth during the month of December 2021. The closest approach to the Earth at a distance of 21 million miles occurred on December 12, 2021. The comet made its closest approach to the Sun on January 3, 2022. The comet’s orbital track around the Sun provided an extra gravitational force “sling shot” impulse to speed it up and place it on a hyperbolic orbit with an escape velocity that will allow it to completely escape the solar system into interstellar space. It will never to be seen again.

The colors of Comet Leonard in the Flickr close-up photo reveal some of the chemical makeup of its body. While the comet was in the inner part of the solar system, the surface of the comet (its nucleus) heated up and the frozen materials started to outgas from its surface, thus forming the long comet tail visible in the Flickr photo. The nucleus, which is the solid body of the comet, is enshrouded in a green color halo (coma) in the Flickr photo. The green color of the rarified atmosphere surrounding the nucleus is indicative of the presence of diatomic carbon and cyanogen gas being liberated from the frozen surface due to the heat of the Sun. Other common chemicals that are present in the constitution of comets are water, oxygen, nitrogen, carbon monoxide, hydrogen cyanide, formaldehyde, ethanol, ethane, long chain hydrocarbons, amino acid, and organic molecules.

The comet’s tail is made of dust particles and ionized atoms and molecules. The tail has a variable length depending on the comets distance from the Sun. As the comet gets closer to the Sun, the increasing heat vaporizes more and more gas which makes the tail longer and longer. The vaporized gases give the comet an atmosphere which changes in density as a function of its distance from the Sun. The strong solar wind (streams of charged particles) from the Sun causes the tail to point in the opposite direction to the Sun. This is the case whether comet is approaching or receding from the Sun. The magnetic fields of the solar winds can cause two tails to appear since ionized atoms and molecules can be forcefully separated from the dusty portion and move is slightly different direction. The tail is rarified mixture of dust and gas as observed by the fact that you can easily see the distant stars through it in the Flickr photo.

An iTelescope hosted PlaneWave CDK20 (20 inch diameter) astrograph was used to capture the imaging data for the Comet Leonard shown in the Flickr photo. The astrograph is located at iTelescope’s Siding Spring Observatory in New South Wales, Australia. The PlaneWave CDK20 astrograph used three wideband color filters (Red, Green, and Blue) that were inserted between the telescope and the camera to acquire the complete set of imaging data used to make the final true color data of my Flickr photo.

The total exposure time taken with the red, green, and blue wideband filters was 20 minutes. 160 megabytes of calibrated data was downloaded to my home PC via the Internet for processing. The following software was used to process the raw data: PixInsight, Photoshop 2021, Topaz Denoise AI, and Topaz Sharpen AI.

This will probably be our last look at comet C/2020 F3 NEOWISE, as it moves out of range of the permanently mounted telescope in our observatory.

I made this photo at 2158 EDT on 25 July, 2020, with a Canon 5D Mark IV on a Takahashi FSQ-106ED ƒ5 refracting telescope, mounted on a Bisque Paramount MyT. The sky was hazy.

• MacOS X Catalina on a MacBook Pro.

• Mount control: TheSkyX Professional.

• Camera control: Canon Utility.

• Single Exposure of 23 seconds @ ISO 800.

• Processed in Lightroom Classic on MacOS.

• The dimmest stars that I can find in this photo have an apparent magnitude m of 13.

• The coma of many comets contains cyanogen gas (CN) and diatomic carbon (C2). Both of these substances glow green when illuminated by sunlight. This is called resonant fluorescence.

Comet C/2020 F3 NEOWISE on July 27th 2020. Coma has a nice green glow probably from cyanogen gas. Transparency was poor from humidity after a 97F temperature during the day. Light from the first quarter moon also affected the image. Williams Optics GT71 Triplet f/5.9 Refractor, Canon T7i camera, ISO800, 21x18sec light frames, 30 flats, 30 darks.

C/2023 E3 ZTF is a comet from Oort cloud whihc visited us 50.000 years before last time. The comet has a bright green glow around its nucleus which is due to the effect of sunlight on its molecules, especially diatomic carbon and cyanogen.Closest distance from Earth is 42 million km. It was discovered by astronomers Bryce Bolin and Frank Masci using the Zwicky Transient Facility (ZTF) survey on 2 March 2022.

Technical details of photo:

Eger, 2023 January 24

Camera: Nikon D5300

Camera control: APT

Lens: F5 coma corrector

Filter: Explore Scientific CLS filter

Telescope: SW 150/750 newton

Mechanics: SW HEQ-5PRO Goto

Guiding: PHD2 autoguiding

Photos: 30x60sec, ISO 800 + flat, dark, bias

Image processing: DSS, PS

Comet 46P/Wirtanen close to the Pleiades (M45) on 16 December 2018 (imaged from Southern Africa, after a thunder shower and in between clear gaps in partly clouded conditions).

The Comet's tail was only visible in darker skies with longer exposures, but it has a beautiful bright green coma. The green colour is caused by Cyanogen (CN) and diatomic Carbon (C2), which glows in the green part of the Electromagnetic Spectrum of Light when illuminated by the Sun in space.

Geocentric Distance:

0.0775 AU (Astronomical Unit)

30 Lunar distances

11.5 million km

7.1 million miles

Gear:

Nikon AF-S NIKKOR 200-500mm f/5.6E ED VR Lens.

Celestron AdvancedVX Telescope Mount.

Optolong L-Pro Clip-In Filter for Nikon.

Nikon D750 DSLR

Lights/Subs:

46 x 60 sec. ISO 320 exposures.

Calibration Frames:

30 x Bias

20 x Darks

Processing:

Pre-Processing and Linear workflow in PixInsight,

and finished in Photoshop.

Martin

Photographed on 7th February 2023. The bright green glow around it's nucleus is though to be due to the effect of sunlight on diatomic carbon and cyanogen. The comet nucleus is estimated to be about a kilometer in size.

It's closest approach to Earth was on the 1st February when it was approximately 25,000,000 miles away and reached magnitude 5, just about visible to the naked eye in dark skies.

Front row (L to R): Bernard, Cupcake, Noogler, Rupture

Middle row (L to R): Greeneon, Hexcode, Android, Bluebot, Cyanogen

Back row (L to R): Iceberg, GD-927, Racer, Blackbeard

Taken with Motorola MotoG3. Processed with Cyanogen Gallery Next for Android.

The comet was drifting in the vacant space, 180 million km away from us in Aquarius. The coma was shining bluish green of C2, radical bi-atomic carbon, vaporized from the comet and illuminated by sunlight. The wavelength peaks at 520nm.

aaadelhi.org/comet-green-color-cyanogen

A bright meteor shone near the yellowish bright star, Situla, Kappa Aquarli, mag. 5.03. The phenomenon occurs about 100km above us in stratosphere near the surface of our globe. The yellowish green looked a bit different from the bluish green of the comet. The wavelength is 557.7nm from oxygen, ionized by high temperature due to friction between the meteorite and our atmosphere. The wavelength is identical with auroral green.

articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bi...

Here is a frame of aurora, taken in Alaska January 2013.

www.flickr.com/photos/hiroc/8400041359

We can feel it green, when aurora is strong enough.

Earth distance: 1.197 AU

Sun distance: 1.055 AU

equipment: Takahashi FSQ-106ED, F3 Reducer 0.6X, and Canon EOS 5Dmk3-sp4, modified by Seo-san on Takahashi EM-200 Temma 2 Jr, autoguided at a star nearby with Fujinon 1:2.8/75mm C-Mount Lens, Pentax x2 Extender, Starlight Xpress Lodestar Autoguider, and PHD Guiding 2

exposure: 1 shot x 1 minute at ISO 12,800 and f/3

The first exposure started at 09:15:59 April 30, 2017UTC.

site: 2,317m above sea level at lat. 24 38 26 South and long. 70 17 13 West on route B-750 near the access road to Armazones Observatory in Atacama Desert Chilethey

`I have macular degeneration in both eyes, and drusen in my right eye, which renders it effectively useless. My ability see low-contrast objects is very restricted. Except on the darkest nights, I can only see Polaris with averted vision. Thus, I had little hope of seeing C-2020 F3 NEOWISE with my unaided eye.

I knew, however, that with a little luck with the weather, my wife, Leona, and I could photograph the comet from our tiny observatory at our home in Gambrills, Maryland.

We made this photo at 2209 EDT on 19 July, 2020, with a Canon 5D Mark IV on a Takahashi FSQ-106ED ƒ5 refracting telescope, mounted on a Bisque Paramount MyT. The sky was hazy and on-and-off cloudy. It began raining at 2225 EDT and I closed up shop.

• Mount control: TheSkyX Professional.

• Camera control: Canon Utility.

• Single Exposure of 12 seconds @ ISO 400.

• Processed in Lightroom Classic on MacOS.

• The dimmest stars that I can find in this photo have an apparent magnitude m of 12 or 13.

• The coma of many comets contains cyanogen gas (CN) and diatomic carbon (C2). Both of these substances glow green when illuminated by sunlight. This is called resonant fluorescence.

The comet was in and out of the clouds; this is the best of about 20 exposures.

A COMET, 2 METEORS AND A STAR CLUSTER IN NEBULOSITY!

Well, actually its just comet 46P/Wirtanen, two meteors from the Geminid meteor shower and the Pleiades. Here’s some quick facts about these objects.

The rarest object is Comet 46P/Wiraten, the greenish glow on the left side of the image. This comet was discovered by astronomer Carl Wirtanen in 1948 at Lick Observatory on Mt. Hamilton near San Jose, California. It is about 0.7 miles in diameter and orbits the sun every 5.4 years. Sunday night, December 16, 2018, it will come within 7.1 million miles (about 30 times the distance to the moon) of Earth, the closest any comet has ever been to us. So far, it has only shown a spherical green glow with no readily visible ion tail. The green glow comes from solar excitation of molecules like CN (cyanide/cyanogen) and C2 (diatomic carbon) that have evaporated from the surface as it gets closer to the sun. Excited molecules of these types produce the teal-green color. The comet is just at the limit of being able to see it with unaided eyes. It is easily spotted in binoculars and small telescopes. It is moving across the sky at nearly 500 arcsec per hour. I hope to put together a movie of it’s movement.

The two meteor streaks are members of the Geminid Meteor Shower, an annual event around December 14. While most meteor showers come from the debris shed by comets, the Geminids come from an object more like an asteroid than a comet - a rock comet so to speak - called 3200 Phaethon which has left a massive trail of dusty debris. The exact nature of Phaethon is under debate - is it a near-Earth asteroid or an extinct comet? It may be the remnants of a rocky collision that occurred eons ago. In any event Phaethon produces lots of meteors, some of which are explosive fireballs (which may be what I say on December 3 in Orion) but most of which are slow traveling, long burning multicolored streaks. There were lots of meteors visible all over the sky the morning of December 14 with at least 60-80 per hour observed at Chamisoso (my Sky Quality Meter read from 20.66 to 20.84 mag/sq arcsec through the morning hours).

The blue stars on the right are our old friend the Pleiades (see my earlier post and close up image of this famous asterism). The stars’ blue light is augmented by nearby dust clouds which reflect light from these stars. On Sunday night the comet will be closest to Earth and the Pleiades. Hope for clear weather.

This image is a composite of only two exposures taken on December 14, 2018 at 1:06 AM (left meteor) and 1:29 AM (right meteor) MST at the Chamisoso Canyon Trailhead near Tijeras, New Mexico. This is a full frame image from a 105mm lens (at F2.0) on a Nikon D850 ISO 400, exposed for 1 minute. It was my goal to get at least one meteor in this relatively small field of view. So, I was extremely lucky to get TWO meteors in the field, when hoping for just one. I took 103 exposures and only two had meteors in them.

From the center of Tbilisi city

31x900" sec of Ha, OIII and SII narrowband, 7.8 hours total

Imaging: TS APO80 with QSI 660wsg-8 camera

Software used: Pixinsight 1.8, Cyanogen Maxim DL 6 Pro

My small photo show is now on!

If you are close to Sapporo, please stop by.

I will upload one photo a day.

札幌のカフェで小さな個展を開催しています。

お近くの方はどうぞお立ち寄りください。

nostalgia cyanogen　祖父との対話

cafe&gallery Rabbit On Sapporo

ある時　母から古い封とうを受け取りました

のぞいてみると　わたしが生まれて間もなく亡くなった

祖父の手紙と写真が入っていました

わたしの手にわたってからは

引き出しの中にしばらく置き去りにされていて

誰にも読み返されることはありませんでした

One day, I was handed an old envelope from my mother.

I looked into it, there were the letters and photographs of my Grand

father who passed away when I was two years old.

Those letters and photographs had never red or looked again by anyone

else, because they were left behind the drawer of my desk since then.

photo left:Yashima moor Nagano, 2006 fall pinhole by mistubako

photo right: Gran pa Mastuo in Manchuria, around1930-40.

Comet C/2022 E3 ZTF. This is a reprocessing of an image taken of the comet in early February. The first attempt using just Nebulosity looked a bit messy with traces of star streaks that were not entirely eliminated. The second attempt was done with Deep Sky Staker which yielded a much better result but I preferred the star field from the first attempt so this image is a composite of both.

[From Wikipedia] C/2022 E3 (ZTF) is a long-period comet from the Oort cloud that was discovered by the Zwicky Transient Facility (ZTF) on 2 March 2022. The comet has a bright green glow around its nucleus, due to the effect of sunlight on diatomic carbon and cyanogen. The comet's systematic designation starts with C to indicate that it is not a periodic comet, and "2022 E3" means that it was the third comet to be discovered in the first half of March 2022.

The comet nucleus was estimated to be about a kilometer in size, rotating every 8.5 to 8.7 hours. Its tails of dust and gas extended for millions of kilometers and, during January 2023, an anti-tail was also visible.

The comet reached its perihelion on 12 January 2023, at a distance of 1.11 AU (166 million km; 103 million mi), and the closest approach to Earth was on 1 February 2023, at a distance of 0.28 AU (42 million km; 26 million mi). The comet reached magnitude 5 and was visible with the naked eye under moonless dark skies.

07-08/02/2023

086 x 30-second exposures at Unity Gain (139) cooled to -10°C

100 x dark frames

090 x flat frames

100 x bias frames

Binning 1x1

Total integration time = 43 minutes

Captured with APT

Guided with PHD2

Processed in Deep Sky Stacker, Nebulosity and Photoshop

Equipment:

Telescope: Sky-Watcher Explorer-150PDS

Mount: Skywatcher EQ5

Guide Scope: Orion 50mm Mini

Guiding Camera: Zwo ASI 120 MC and SVBONY SV105 with ZWO USBST4 guider adapter

Imaging Camera: Zwo ASI 1600MC Pro with anti-dew heater

Baader Mark-III MPCC Coma Corrector

Filter: Optolong L-Pro

My small photo show is now on!

If you are close to Sapporo, please stop by.

I will upload one photo a day.

札幌のカフェで小さな個展を開催しています。

お近くの方はどうぞお立ち寄りください。

nostalgia cyanogen　祖父との対話

cafe&gallery Rabbit On Sapporo

ある時　母から古い封とうを受け取りました

のぞいてみると　わたしが生まれて間もなく亡くなった

祖父の手紙と写真が入っていました

わたしの手にわたってからは

引き出しの中にしばらく置き去りにされていて

誰にも読み返されることはありませんでした

One day, I was handed an old envelope from my mother.

I looked into it, there were the letters and photographs of my Grand

father who passed away when I was two years old.

Those letters and photographs had never red or looked again by anyone

else, because they were left behind the drawer of my desk since then.

photo left: Hisa portrait at 18 years old taken by Granpa Matsuo 1922

Green colour is due to cyanogen and diatomic carbon gases.

My small photo show is now on!

If you are close to Sapporo, please stop by.

I will upload "one photo a day"

札幌のカフェで小さな個展を開催しています。

お近くの方はどうぞお立ち寄りください。

nostalgia cyanogen　祖父との対話

cafe&gallery Rabbit On Sapporo

ある時　母から古い封とうを受け取りました

のぞいてみると　わたしが生まれて間もなく亡くなった

祖父の手紙と写真が入っていました

わたしの手にわたってからは

引き出しの中にしばらく置き去りにされていて

誰にも読み返されることはありませんでした

One day, I was handed an old envelope from my mother.

I looked into it, there were the letters and photographs of my Grand

father who passed away when I was two years old.

Those letters and photographs had never red or looked again by anyone

else, because they were left behind the drawer of my desk since then.

photo left:front my mother and back her older sister. this was taken in Manchuria, 1937.

photo right:my room by the window (pinhole)