These two Messier objects lie quite close together, see previous image for a full frame view.

M97. The Owl planetary nebula is about 3.7 arcminutes across in our sky but is actually 0.91 light years in diameter. It lies about 2600 light years distant. The central star has shed its outer layers which glow either red (hydrogen) or green-blue (oxygen) lit by the intense UV light of the remnant white dwarf star in the centre. Eventually, the star will cool and the gas will expand until the nebula fades away. It estimated that the nebula is about 6000 years old based on its size and expansion rate. Our own Sun may eventually suffer a similar fate.

A gravitational effect has formed a constrained tube of gas near the star before it expands into a sphere. We are looking down at about 45 degrees to the axis of the tube, these effects produce an "owl face" from our perspective.

Barred spiral galaxy M108 is about 45 million light years away and is almost edge on from our perspective. It’s 8.7 x 2.2 arcminutes diameter in our sky. It lacks a prominent core or bulge but has numerous dark dust lanes. It’s possible to see

a small yellow core at its centre (yellow or red stars tend to be old and mature) brownish dust lanes, pink hydrogen alpha zones and two bright blue "stellar associations” of young intensely bright stars at this magnification.

A Type II supernovae was observed here in 1969.

Technical card on previous full frame image.

The Triffid Nebula using a remote telescope at telescope live stacked using photoshop and coloured using Siril

Taken from Coral Towers Observatory using an SBIG STL-11000 camera and Takahashi BRC 250 telescope on a Software Bisque PME Mount.

H-alpha filter; 6 hours exposure total (36 x 10 min)

LINK

Other images from this series:

False Colour: www.flickr.com/photos/jbrimacombe/51610243560/

Mono: www.flickr.com/photos/jbrimacombe/51608539717/

Negative Mono: www.flickr.com/photos/jbrimacombe/51608539662/

This was taken with the Stone Edge Observatory 20 inch telescope near Sonoma California. This is a bicolor image with h-alpha and oiii data. There is a total exposure of 3hr57m in h-alpha and 1hr29m40s total in oiii. The exposure is probably a little overkill... but I had the time to do it.

The Pleiades, also known as the Seven Sisters and Messier 45, are an open star cluster containing middle-aged, hot B-type stars in the north-west of the constellation Taurus. It is among the star clusters nearest to Earth, it is the nearest Messier object to Earth, and is the cluster most obvious to the naked eye in the night sky.

The cluster is dominated by hot blue and luminous stars that have formed within the last 100 million years. Reflection nebulae around the brightest stars were once thought to be left over material from the formation of the cluster, but are now considered likely to be an unrelated dust cloud in the interstellar medium through which the stars are currently passing.

Equipment:

Scope: Lacerta 72/432 F6 0.85x reduktorral (367mm F5.1)

Mount: Skywatcher EQ-5 Pro Synscan Goto

Guide scope: Orion 50mm mini

Guide camera: ZWO ASI120mm Mini

Main camera: ZWO ASI183MM-Pro cooled monochrome camera

Accessories:

ZWO ASIAIR Pro

ZWO EFW 8x1.25"

Lacerta Dew-heater 20cm

Lacerta Dew-heater 30cm

Programs:

PixInsight

Adobe Photoshop CC 2020

Details:

Camera temp: -15°C

Gain: 53

Astronomik L-3 UV-IR Block: 92x180s

Astronomik Deep-Sky R: 16x180s

Astronomik Deep-Sky G: 14x180s

Astronomik Deep-Sky B: 20x180s

Description: This image of spiral galaxy M33 (or NGC 598), the Triangulum Galaxy, was developed from 124x300s subs or about 10 hours of total exposure time. Of interest is the presence of the irregular-shaped nebula NGC 604, an HII region, in one of the spiral arms. Initially, I found it difficult to locate NGC 604, but once I did, I decided for future reference to identify it with a magnification inset as shown in the image.

Date / Location: 1-5 December 2022 / Washington D.C.

Equipment:

Scope: WO Zenith Star 81mm f/6.9 with WO 6AIII Flattener/Focal Reducer x0.8

OSC Camera: ZWO ASI 2600 MC Pro at 100 Gain and 50 Offset

Mount: iOptron GEM28-EC

Guider: ZWO Off-Axis Guider

Guide Camera: ZWO ASI 174mm mini

Focuser: ZWO EAF

Light Pollution Filter: Chroma LoGlow Broadband

Processing Software: Pixinsight

Processing Steps:

Preprocessing: I preprocessed 124x300s subs (= 10.3 hours) in Pixinsight to get an integrated image using the following process steps: Image Calibration > Cosmetic Correction > Subframe Selector > Debayer > Select Reference Star and Star Align > Image Integration.

Linear Postprocessing: Rotation > Dynamic Crop > Dynamic Background Extractor (both subtraction to remove light pollution gradients and division for flat field corrections) > Background Neutralization > Color Calibration > Noise Xterminator.

Nonlinear Postprocessing and additional steps: Histogram Transformation > Local Histogram Equalization (2 cycles) > Curves Transformation (2 cycles) > SCNR Noise Reduction (2 cycles).

The Ring Nebula

A planetary nebula - a star has ejected its outer layers as it nears the end of its life. The central remnant white dwarf gives off extremely hard UV light which makes the shells of gas fluoresce. Blue/Green is Oxygen. Red is Hydrogen and Nitrogen. Yellow is an overlap of Green + Red.

At a diameter of 1 arc minute, it is only about 60 pixels across at this image scale. The central white dwarf which has a surface temp of about 100000c can just be seen.

Diameter is 1 arcminute

ZWO ASI2600MC 61 x 3 minute subs at gain 100, offset 50 at 0c.

Equinox ED 900mm f/7.5 scope x0.85 focal reducer.

IDAS P3 LPS 2" filter in focal reducer.

SkyWatcher EQ6 pro mount with Rowan belt drives.

Guided by PHD2 via PrimaLuce 240mm f/4 guidescope.

Atmospheric

Clear throughout. No subs lost.

Light pollution; 20.02 measured with Unihedron SQM (L)

Calibration

50 flats (EL panel at 1/4 second)

50 darks at 0c

50 bias at 0c and 1/16000s

Processing

PixInsight 1.8.8

Polar Alignment:

“Resume from Park” - I left the scope up from last time.

Error measured by PHD2= 0.2 arc minute.

RA drift + 1.27 arcsec/min

Dec drift +0.05 arcsec/min

Guiding:

PHD2 guiding with ZWO ASI290mm/PrimaLuce Lab 240/60mm guide scope. Multi-star guiding.

RA RMS error 0.61 arcsec.

Dec RMS error 0.64 arcsec.

Astrometry:

Resolution ............... 0.987 arcsec/px

Focal distance ........... 785.59 mm

Pixel size ............... 3.76 um

Field of view ............ 33' 10.2" x 26' 8.7"

Image center ............. RA: 18 53 35.937 Dec: +33 01 49.32

There was a little tilt between focuser draw tube and focal reducer which distorted the stars. I used Free Transform in Photoshop to distort and tilt the image back again!

Overall, I need to get the colour balance sorted out and probably use no more than about 2 minute exposures.

Taken with a TMB92L, Canon T3i DSLR, Orion SSAG autoguider and 50mm guidescope, and Celestron AVX mount. Consists of 30 180-second light frames and 18 180-second dark frames, all at ISO 800, as well as 15 flat and 30 bias frames. Captured with BackyardEOS, stacked in DeepSkyStacker, and processed in Photoshop.

One of my fist short exposure learning/test Astro-images, photographed close to the city.

The Lagoon Nebula (M8, Messier 8 or NGC 6523) is a giant interstellar cloud in the constellation Sagittarius. The Lagoon Nebula is estimated to be between 4000 - 6000 light years from Earth in the Milky Way Galaxy, and is classified as an emission nebula.

Emission nebulae are glowing clouds of interstellar gas which have been excited by some nearby energy source, usually a very hot star. The red light seen in this picture is glowing hydrogen captured in the Hydrogen-Alpha (Hα) Infrared wavelength of light at 656nm.

Photographed rather close to the "light polluted" suburbs of the West Rand and North Rand of Johannesburg (Gauteng Province, South Africa). Light Pollution Map .

Astrometry info::

RA, Dec center: 271.058268626, -24.3623113276 degrees

Orientation: 0.715439826321 deg E of N

Pixel scale: 4.18683362403 arcsec/pixel

nova.astrometry.net/user_images/774837#annotated

Gear:

GSO 6" f/4 Imaging Newtonian Telescope (Astrograph).

Celestron Advanced VX Equatorial Mount.

Orion UltraBlock Narrowband Light Pollution Filter.

Canon 60Da DSLR (sensitive to IR light at 656.28 nm).

Processed in PixInsight.

Polar Aligned, but Unguided.

Stacked 20 sec. exposures (Lights/Subs).

Calibration Frames: Darks and Bias frames (no Flats).

Martin

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M37 is one of three Messier objects that is an open cluster in the constellation Auriga. It passes overhead from my latitude. This was a somewhat humid night, which I think accentuated the colors of stars in the cluster.

Stack of 19 45s exposures shot through a Celestron Edge HD 925 at f/2.3 with Hyperstar and an Atik 314L+ color CCD with Baader UHC LP filter. Preprocessing in Nebulosity, stacking and initial processing in PixInsight, final touches in PS CS 5.1.

The image center (J2000) is at

RA 5h 52m 22s

DEC +32° 32' 52"

Also known as the Ring Nebula in the constellation Lyra. It is also a planetary nebula with a distance of 2300 +/-1500-700 light years. This exposure is three and a half hours total integration. Nearby (although much further away!) is a cross-linked barred spiral galaxy known as IC 1296. It sits at a rough distance of 235 million light years.

Captured using a 10-inch Meade LX200 Schmidt-Cassegrain telescope and a Nikon DSLR at the Loowit Imaging observatory in Shelton, Washington.

Description: Going from bottom right to top left along a curve in this image of the Markarian's Chain in the Virgo Cluster are M84, M86, NGC 4438, NGC 4435, NGC 4461, NGC 4473 and NGC 4477. The magnification inset shows the "Markarian's Eyes" NGC 4438 and NGC 4435.

Date / Location: 13-14 April 2023 / Washington D.C.

Equipment:

Scope: WO Zenith Star 81mm f/6.9 with WO 6AIII Flattener/Focal Reducer x0.8

OSC Camera: ZWO ASI 2600 MC Pro at 100 Gain and 50 Offset

Mount: iOptron GEM28-EC

Guider: ZWO Off-Axis Guider

Guide Camera: ZWO ASI 174mm mini

Focuser: ZWO EAF

Light Pollution Filter: Chroma LoGlow Broadband

Processing Software: Pixinsight

Processing Steps:

Preprocessing: I preprocessed 37x300s subs (= 3.1 hours) in Pixinsight to get an integrated image using the following processes: Image Calibration > Cosmetic Correction > Subframe Selector > Debayer > Select Reference Star and Star Align > Image Integration.

Linear Postprocessing: Dynamic Background Extractor (both subtraction to remove light pollution gradients and division for flat field corrections) > Background Neutralization > Color Calibration > Noise Xterminator.

Nonlinear Postprocessing: Histogram Transformation > Local Histogram Equalization.

Taken with a TMB92L, Canon T3i DSLR, and Celestron CG-4 mount. Consists of 38 light and 29 dark frames, each a 35-second exposure at ISO 800, stacked in DeepSkyStacker and processed in Photoshop.

This Hubble Space Telescope image of M80 features observations in ultraviolet, visible, and infrared wavelengths of light. This data helped scientists learn more about the sequence of cosmic events that lead to the formation of various sub-populations of stars in globular clusters like this one.

Credit: NASA, ESA, and G. Piotto (Universita degli Studi di Padova); Image Processing: Gladys Kober

For more of Hubble's Messier Catalog, visit: www.nasa.gov/content/goddard/hubble-s-messier-catalog

Taken with a TMB92L, Canon T3i DSLR, Orion SSAG autoguider and 50mm guidescope, and Celestron AVX mount. Consists of 35 120-second light frames and 35 120-second dark frames, all at ISO 800, as well as 20 flat and 50 bias frames. Captured with BackyardEOS, stacked in DeepSkyStacker, and processed in Photoshop.

Equipment:

Scope: Lacerta 72/432 F6 0.85x reduktorral (367mm F5.1)

Mount: Skywatcher EQ-5 Pro Synscan Goto

Guide scope: Orion 50mm mini

Guide camera: ZWO ASI120mm Mini

Main camera: ZWO ASI183MM-Pro cooled monochrome camera

Accessories:

ZWO ASIAIR Pro

ZWO EFW 8x1.25"

Lacerta Dew-heater 20cm

Lacerta Dew-heater 30cm

Programs:

PixInsight

Adobe Photoshop CC 2020

Details:

Camera temp: -15°C

Gain: 111

Astronomik 6nm Ha:

18x300s

10x30s

10x60s

Messier 39 / M39 / NGC 7092

Barnard 363 / B 363 / LDN 1007

M39 is an open cluster about 1,000 light-years away. This young cluster, estimated to be 280 million years old, appears as a sparse group of blue stars in front of the rich Milky Way star field that runs through the constellation of Cygnus. Dark nebula structures (interstellar clouds made of gas and dust) are scattered across the field. Barnard 363 is the dark nebula towards the upper right.

Just 1 year earlier, I attempted this target with a 250mm lens on a cheap tracking mount: flic.kr/p/2cbMn7b

Total integration: 5 hours 14 minutes (314 minutes)

11/25/19: 82 x 120 seconds ISO400

11/28/19: 75 x 120 seconds ISO400

Location: Charlottesville, VA

SQM: 19.22 mag/arcsec^2 (Bortle 6)

Camera: Canon T3i (stock/unmodified)

Average camera temperature: 84 F (29 C)

Telescope: Explore Scientific ED80 f/6.0 Apochromatic Refractor (with ES field flattener)

Mount: Orion Sirius EQ-G

Guide scope: Svbony 50mm f/4.0 Guide Scope

Guide camera: Orion StarShoot AutoGuider

Software: N.I.N.A. with ASTAP (slewing and plate solving), PHD2 (guiding), Magic Lantern (image capture)

Pre-processed with PixInsight, processed with PixInsight and Paint.NET

This is an example of what you can get with a DSLR and some of the darkest skies on the planet. This is a stack of 19 10 s exposures with a Canon Rebel T1i. Dark frames were subtracted, and the resulting images were registered, stacked, and initially processed in PixInsight. Final processing was in PS CS 5.1.

This part of the sky was 50° to 60° above the horizon at this time, and there was no light pollution. The zodiacal light looked like a flashlilght beam going into the sky after sunset. Scorpius and Sagittarius are the constellations that fill this view, including a multitude of emission nebulae, younger open star clusters, and older globular clusters. The most prominent glow is from the bulk of stars in the direction of the center of our galaxy, the Milky Way. The features that stand out the most, in my opinion, are all the clouds of dark molecular material and dust that cut across the brighter background features. This is where stars are being born - in all of those little wisps and puffs of darkness. Many of those are tens of light years across, and they conceal the next generation of stars in our galaxy.

LATEST VERSION: flic.kr/p/2qbsjKf

Messier 7 / M7 / NGC 6475 / The Ptolemy Cluster

NGC 6453

M7 is a bright, loose open cluster in the constellation of Scorpius. It is about 980 light-years away and it is estimated to be 200 million years old. From our perspective, M7 lies in front of the Galactic Center (the center of the Milky Way). As a result, the dense starfield behind this cluster is the richest of all Messier objects and one of the richest in the entire night sky.

NGC 6453 is a globular cluster about 38,000 light-years away. It is heavily obscured by interstellar dust since it lies behind the Galactic Center. The cluster appears as a golden clump between M7 and the left edge of the frame.

2 years ago, my first attempted deep-sky image featured M7: flic.kr/p/2a8e8s2

1 year ago, this was my much-improved result: flic.kr/p/2hc2S3M

Total integration: 16 hours 37.5 minutes (997.5 minutes)

06/22/19: 307 x 30 seconds ISO800

08/17/19: 62 x 60 seconds ISO200

08/19/19: 168 x 60 seconds ISO200

06/25/20: 90 x 120 seconds ISO200

06/28/20: 55 x 120 seconds ISO200

06/29/20: 94 x 120 seconds ISO200

07/14/20: 68 x 120 seconds ISO200

Location: Coral Springs, FL

SQM: 18.18 mag/arcsec^2 (Bortle 8/9)

Camera: Canon T3i (stock/unmodified)

Average camera temperature: 104 F (40 C)

Telescope: Explore Scientific ED80 f/6.0 Apochromatic Refractor (with ES field flattener)

Mount: Orion Sirius EQ-G

Guide scope: Svbony 50mm f/4.0 Guide Scope

Guide camera: Orion StarShoot AutoGuider

Software: N.I.N.A. with PlateSolve2 and PHD2

Processed with PixInsight and Paint.NET

M50 (NGC 2323) is an open star cluster that lies at the eastern edge of the Winter Hexagon. The view here has north roughly at the top.

Shot with a Celestron Edge HD 925 at f/2.3 with Hyperstar and a mono Atik 414-EX camera with LRGB filters from Optolong.

Stacking info:

L channel - 95 20 s exposures

R channel - 31 60 s exposures

G channel - 27 60 s exposures

B channel - 29 60 s exposures

Preprocessing in Nebulosity; registration, stacking, channel combination and initial processing in PixInsight; final touches in Photoshop

24x30s R

30x30s G

29x30s B

Imaging telescopes or lenses: Explore Scientific 127 ED APO Carbon

Mounts: SkyWatcher EQ6-R Pro

Guiding telescopes or lenses: Artesky Ultraguide 70mm

Guiding cameras: Orion Starshoot Autoguider Orion Starshoot

Focal reducers: Explore Scientific 0.7 Reducer/Flattener

Software: PixInsight · N.I.N.A · PHD2

Filters: ZWO LRGB 1.25" Filters

Accessory: Pegasus Astro Pocket Powerbox Advance · Pegasus Astro Focus Cube2 · ZWO EFW 1,25"

Taken with a Sigma AF 70-300mm f/4-5.6 APO DG at 200mm and f/6.3, Canon T3i DSLR, and Celestron Advanced VX mount. Consists of 100 light and 43 dark frames, each a 60-second exposure at ISO 3200. Captured with BackyardEOS, stacked in DeepSkyStacker, and processed in Photoshop.

Visible right next to the stinger of the scorpion in the constellation Scorpius, Messier 7 is an easy naked-eye target for stargazers in southern latitudes. The second-century astronomer Claudius Ptolemy first recorded this open star cluster in 130 AD, earning it the nickname Ptolemy's Cluster.

Open star clusters contain stars formed from the same initial cloud of gas and dust and are typically irregular in shape. Over time, as open clusters revolve around a galaxy, gravitational disruptions from other cosmic objects can disperse the stars. Ptolemy’s Cluster is one of more than a thousand open clusters in the Milky Way and contains about 80 stars. Residing about 980 light-years from Earth, M7 likely formed about 220 million years ago.

Astronomer Charles Messier added the cluster to his catalog in May 1764. M7 is the southernmost Messier object, making it challenging to see for those in northern latitudes. It is located close to Messier 6, the Butterfly Cluster, and both can be spotted without binoculars or small spotting telescopes. Both M7 and M6 are best viewed from the northern hemisphere around 10 p.m. in July, when the Scorpio constellation is highest in the sky.

Credit: NASA, ESA, D. Bennett (University of Maryland), and K. Sahu (STScI); Image Processing: Gladys Kober

For more of Hubble's Messier Catalog, visit: www.nasa.gov/content/goddard/hubble-s-messier-catalog

I have a fondness for this cluster related to teaching astronomy labs. Our college has a set of 8" Dobsonians that we give our students a chance to use. At first, I will aim the scope so they get used to the view throught the scope compared to the view through the Telrad. I then hunt down some bright deep sky objects for them to view and sketch. Typically, there are eight scopes and 24-30 students, so they have to wait as I get around to each group. Some students decide to explore on their own, which makes me really happy. Usually, they aim the scope at random areas of the sky, but every so often they come across something. This particular autumn evening, while we were looking at objects in Cassiopeia, some students decided to go exploring while they waited for me to find a new object. We had looked at a few star clusters at this point, so they called me over.

"We think we found a star cluster!" they said.

I checked, and indeed they had! Looking through the Telrad, I could see we were on one side of the W of Cassiopeia. I showed them on Stellarium where we were looking and identified it as M103.

Is this a particularly spectacular cluster? Probably not, but I love that I now have this story attached to it. When you get to use a telescope, go exploring. Who knows what you might come across? Sure, chances are very high that it has already been discovered and cataloged, but *YOU* haven't seen it before. Enjoy that sense of personal discovery.

This is a stack of 32 30 s exposures with the Nikon D5100 at ISO 1600 while it was mounted at the back of my Celestron Edge HD 925. You can see that the guiding is a bit off. I took this on the night of 2021-11-10. The effective focal length was 2210 mm. Preprocessing, registration, stacking, and most processing was done in PixInsight. Final processing in Photoshop.

Two spiral galaxies from the Messier catalogue lying in Coma Berenices. Imaged over 2 nights which is a rarity for me in cloudy Northern Ireland.

Messier 88 lies top right and is a classic spiral galaxy. It measures 6.9 x 3.7 arcminutes. A supernova was detected there in 1999.

Messier 91 lies bottom left, it is a barred spiral galaxy and is classified as "anaemic" - see below! It measures 5.4 x 4.3 arcminutes.

Both galaxies lie in the Virgo galactic cluster which comprises many thousands of galaxies moving at speed under the influence of local gravity. Eventually, they will all collide at the local centre of gravity.

Tenuous hot gases and dust lie inbetween the galaxies forming a hot intracluster medium. As the galaxies race through the resistance of the medium, ram pressure stripping shears their own gas away and leaves them increasingly incapable of forming young new blue stars.

Messier 91 shows this effect more than M88 - it is pale and yellowish for a spiral galaxy - hence anaemic!

Some interesting small galaxies are seen in the field including on the mid right border, a small irregular spiral galaxy - IC 3476 which appears disrupted - probably by approaching too close to a larger galaxy in the past.

Technical Card:

900/120mm f/7.5 Equinox ED doublet refractor.

Skywatcher x 0.85 FR with 2 inch IDAS LPS P3 filter

MoonLite electronic focuser

Astro-modified Canon 80D at ISO400; 26 x 10 minute subs

QHY PoleMaster for polar alignment.

NEQ6 pro mount with Rowan belt drives -2 star align.

Camera control with Backyard EOS

Post processed in PixInsight 1.8.8

60 Flats EL panel: 1/40s @ ISO400

Master Dark from Dark Library, 50 x ISO and Temp. matched.

Master Bias from Library, 03/2021

Camera sensor temperature (external battery): 12-14c

Local parameters:

Temp: 7.0 - 9.2c

Humidity: 55.4%

Pressure: 1010 hPa

Light Pollution and Weather:

SQM (L) at end of session night 1 (0110 hrs UT) =20.33 mag/arcsec2. Clear both nights throughout - no subs lost due to weather.

Astrometry:

Center (RA): 12h 33m 40.785s

Center (Dec): +14° 24' 26.77"

Size: 1d 01m 58.9s x 50m 35.3s

Image scale: 0.977 arcsec/pixel

Focal distance: 792.08mm

Pixel Size 3.75 microm

Polar Alignment:

QHY Polemaster alignment -

Error measured by PHD2= 2 arc minute.

RA drift + 2.07 arcsec/min

Dec drift + 0.52 arcsec/min

Guiding:

PHD2 guiding with ZWO ASI290mm/PrimaLuce Lab 240/60mm guide scope. Every 3rd shot dithered.

RA RMS error 1.3 arcsec.

Dec RMS error 0.84 arcsec.

Personal Notes:

Compared with my last session with this setup - I was pleased to see that the IDAS P3 LPS filter was much better than the D2 filter - subs showed less background light pollution and the horrible star haloes have gone!

The trailed stars produced by differential flexure in my guidescope have also disappeared - just tightened all the guidescope connections.

Even the great observer Charles Messier had trouble seeing this globular cluster when building his Catalog of Nebulae and Star Clusters. It was originally spotted in 1752 by a French astronomer in what is now South Africa, but it took until 1778 for Messier to catalog it.

This is because, while Messier 55 is large and reasonably bright, it is lacking a dense core and many of its stars are quite faint, making it hard to observe in non-optimal conditions.

For northern observers M55 sits low in the sky, so the view is hampered by a thicker layer of atmosphere, as well as water vapor and light pollution. This hindered Messier’s view from his Paris observatory. When he cataloged it, Messier noted that “its light is even and does not appear to contain any star.”

Though this image shows just a portion of M55, the cluster as a whole appears spherical because the stars’ intense gravitational attraction pulls them together. Hubble’s clear view above Earth’s atmosphere resolves individual stars in this cluster. Ground-based telescopes can also resolve individual stars in M55, but fewer stars are visible.

Even in skies with low light pollution, viewed through binoculars, the cluster will only appear as a round hazy patch. Small telescopes can begin to resolve individual stars in M55, while larger aperture telescopes will pick out low magnitude stars easily. The star cluster is found in the southern part of the constellation Sagittarius and is easiest to spot in August.

The globular cluster is about 20,000 light-years away and has a diameter of about 100 light-years. It contains an estimated 100,000 stars with 55 variable stars whose brightness changes.

Credit: NASA, ESA, A. Sarajedini (Florida Atlantic University), and M. Libralato (STScI, ESA, JWST); Image Processing: Gladys Kober

For more of Hubble's Messier Catalog, visit: www.nasa.gov/content/goddard/hubble-s-messier-catalog

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This Hubble Space Telescope image of M14 includes observations taken in ultraviolet, visible, and near-infrared wavelengths of light. Astronomers used this data to better understand the formation and chemical makeup of different populations of stars that reside within this cluster.

Credit: NASA, ESA, and F. D'Antona (INAF, Osservatorio Astronomico di Roma); Image Processing: Gladys Kober

For more of Hubble's Messier Catalog, visit: www.nasa.gov/content/goddard/hubble-s-messier-catalog

I read an article in Sky and Telescope online today by Bob King with the above title. I’d recently imaged Messier 3 and wondered if I could use the diagrams in the article to find the star near the globular cluster’s core.

I went back to my linear image and performed a very gentle stretch so as not to obscure the core stars and altered the orientation to match the diagrams. As this is an image of just the core of the cluster, it’s rather small.

The star marked in the image above was the first variable star located in a globular cluster. It’s magnitude varies between 11.8 and 13.2 over a period of 15.3 days. That longer period classifies it as a W Virginis type star or a Type II Cepheid. Most of the variables in M3 are RR Lyrae type with shorter periods.

The star pulsates regularly as an outer layer contracts slightly then heats up and traps energy radiating from the core. The star then dims slightly until rising pressure pushes the layer back out. And repeat... ...every 15.3 days.

It fuses Helium at its core with Hydrogen burning occurring in an outer shell. Variations in the pressure and temperature of the shell cause the pulsations.

The relationship between the luminosity and period of stars like this can be used as a “standard candle” to work out the distance to stars.

The stars light curve was first described by EE Barnard in 1906 and hence it is known as Barnard’s variable.

After this exercise, I can spot V154 in my main image of M3, it is somewhat brighter and whiter than most of the stars in the cluster.

Not certain but I think it is likely to be a F class star so hotter and bluer than most stars in a Globular cluster.

Exif:

Mount: Skywatcher EQ-5 Pro GoTO

Scope: Lacerta 72/432 w/ 0,85 reducer

Camera: Pentax K-1 (unmodified)

Guider: Orion 50mm and Zwo 120mm mini with ASIAIR

Exposures:

22x600s, ISO800

28x300s, ISO800

Calibrated with dark and bias.

I shake my head every time I look at this image. What an amazing view of the stars in the Milky Way! Photographed from the edge of Lake Burley Griffin, less than 500m from our apartment, in the middle of Canberra.

The photograph shows a portion of the Milky Way, centered on the constellation of Sagittarius, but with the constellation of Scorpius on the left edge of the image. The twin bright stars of Shaula and Lesath forming the tip of the scorpions tail can be seen in the lower left corner. Messier Object 6 (The Butterfly Cluster) is the bright cluster of stars close to the center bottom edge of the image. Messier Object 7 (Ptolemy's Cluster) is the bright collection of stars just left of the center of the image. Messier Object 8 (The Lagoon Nebula) is the bright feature on the center of the right edge.

The Messier Objects are a list of over 100 objects that were catalogued by Charles Messier, an 18th and 19th century French astronomer. It is fascinating that he created the list in 1771, not to study them, but to help him to ignore these bright features in his quest to find new comets.

earthsky.org/brightest-stars/scorpion-stinger-stars-also-...

en.m.wikipedia.org/wiki/Charles_Messier

en.m.wikipedia.org/wiki/Messier_object

www.messier-objects.com/messier-6-butterfly-cluster/

www.messier-objects.com/messier-7-ptolemys-cluster/

www.messier-objects.com/messier-8-lagoon-nebula/

[ The rules of thumb for the maximum exposure time (for full frame sensor cameras with 36.0 x 24.0 mm sensor size) such that the stars appear as points of light rather than short star trails are variously known as the "500 Rule" or the "600 Rule". The rules "state" that this maximum exposure time in seconds is 500 or 600 divided by the focal length of the lens. When the crop factor of the CRV-50c sensor is taken into account (sensor size 43.8 x 32.9 mm), the effective full frame sensor equivalent focal length of the 150mm f/4.0 lens used for this photograph is of the order of 120 mm. The maximum exposure time is thus 4 to 5 seconds. I shot this using an exposure time of 6 seconds, an ISO of 3200, and an aperture of f/4. The stars show up as quite distinct trails, suggesting to me that the "old" rules of thumb might need to be updated to take into account the resolution of sensors such as the 50MP one used in the CFV-50c digital back. I might have to create a "250 Rule". ]

Barton, Australian Capital Territory, Australia.

Photography notes ...

The photograph was taken using the following hardware configuration ...

- Hasselblad 500C/M body (1994).

- Hasselblad CFV-50c Digital Back for Hasselblad V mount camera.

- Hasselblad Focusing Screen for the CFV-50c digital back, with focussing prism and crop markings.

- Hasselblad 45 Degree Viewfinder PME-45 42297 (2001).

- Carl Zeiss lens - Sonnar 150mm f4 CFi T* - Nr 8912760 - Hasselblad - Prontor shutter (2003).

- FotodioX B60 Lens Hood for Select Hasselblad Telephoto CF Lenses.

(Year of manufacture indicated in braces where known.)

I acquired the photograph (8272 x 6200 pixels) with an ISO of 3200, exposure time of 6 seconds, and aperture of f/4.

Post-processing ...

Finder - Removed the CF card from the camera digital back and placed it in a Lexar 25-in-1 USB card reader. Then used Finder on my MacBook Air to download the raw image file (3FR extension) from the card.

Lightroom - Imported the 3FR image. Used the Map module to add the location details to the EXIF header. Then applied various adjustments in the Develop module, the essence of which is as follows ...

- White Balance (Temperature and Tint).

- Tone (Exposure, Contrast - Increased, Highlights and Shadows - Increased, Whites - Increased, Blacks - Decreased).

- Presence (Clarity - Increased, Vibrance - Increased, Saturation - Decreased).

- [HSL adjustments as required for selective color adjustments.]

- [Sharpening and Noise Reduction - Default values.]

- [Lens Corrections as required.]

- Dehaze - Increased.

- [Graduated and Radial filters as required for local adjustments.]

I then exported the image as a JPG file with 8272 x 6200 pixels from the Library module.

Harlow Shapley remarked that about 1/3 of the globular clusters in our sky lie in the direction of Sagittarius. M28 (NGC 6626) is one of those many clusters.

Shot with LRGB filters from my backyard in Long Beach, CA.

L: 32 10 s exposures

R: 64 20 s exposures

G: 66 20 s exposures

B: 74 20 s exposures

All taken with an Atik 414-EX mono camera on a Celestron Edge HD 925 at a focal length of 530 mm using HyperStar. LRGB filters are from Optolong and changed with the Starizona filter slider system.

Pre-processing in Nebulosity; registration, stacking, channel combination, and processing in PixInsight; final touches in Photoshop.

Stack of 29 25 s ISO2000 unguided frames taken with a Nikon D5100 on a Celestron Edge HD 925 at 2150 mm focal length.

I like this version better than what I got with the monochrome CCD and filter wheel set.

Captured with a Nikon D5500 and a 10-inch Meade LX200 'Classic' f/6.3 wide-field telescope.

EXIF data is removed via stacking processes in Autostakkert!2 for planetary imaging and in Deep Sky Stacker for deep sky imaging.

M93 (NGC 2447) is an open cluster in Puppis. It's one of the more southerly Messier objects, so there's a shorter window for when I can shoot it from my location in Long Beach. These were taken on 2023-02-15 -- a rare clear night this winter.

I used a Celestron Edge HD 925 with Hyperstar at focal length 535 mm and an Atik 414-EX monochrome camera with Optolong CCD LRGB filters to get the following exposures:

L: 181 10 s exposures

R: 41 30 s exposures

G: 50 30 s exposures

B: 81 30 s exposures

Images were preprocessed in Nebulosity, then stacks were created in PixInsight. Channel combination and initial processing were in PixInsight, with final touches in Photoshop.

Equipment:

Scope: Lacerta 72/432 F6 0.85x reduktorral (367mm F5.1)

Mount: Skywatcher EQ-5 Pro Synscan Goto

Guiding: OAG

Guide camera: ZWO ASI120mm Mini

Main camera: ZWO ASI183MM-Pro cooled monochrome camera

Accessories:

ZWO ASIAIR Pro

ZWO EFW 8x1.25"

ZWO EAF

ZWO OAG

ZWO 1.25 Helical focuser

Lacerta Dew-heater 30cm

Programs:

PixInsight

Adobe Photoshop CC 2020

Details:

Camera temp: -15°C

Gain: 53, 111

Astronomik 6nm Ha: 155x300s

Astronomik L-3 UV-IR Block: 132x180s

Astronomik Deep-Sky R: 20x180s

Astronomik Deep-Sky G: 20x180s

Astronomik Deep-Sky B: 20x180s

Bortle Scale: 4

Location: Isaszeg, Hungary

Acquisition date(s):

2021.02.28., 2021.03.02., 2021.03.06., 2021.03.07., 2021.03.08.,

This image of M19 includes Hubble observations taken in ultraviolet, visible, and near-infrared wavelengths of light. A small gap in Hubble data (horizontal line at center right) is instead filled in with observations from the ground-based Victor M. Blanco 4-meter Telescope. The Hubble proposal associated with this image sought to investigate M19’s formation and the ratios of different populations of stars within the cluster.

Credit: NASA, ESA, and C. Johnson (STScI); Image Processing: Gladys Kober

For more of Hubble's Messier Catalog, visit: www.nasa.gov/content/goddard/hubble-s-messier-catalog

Dates: 23-24, 26-28 April 2025

Location: Washington D.C.

Equipment:

ASI 2600MM Pro (monochrome) camera

Chroma 36mm LRGB Filter Set

WO Fluorostar 91mm f/5.9 triplet APO refractor with Adjustable Field Flattener 68III

iOptron GEM28-EC mount

Data and exposure times:

Data was acquired as LRGB images with the following exposure times:

14.11 hours (242x210s subs) with Luminance filter (L).

3.50 hours (60x210s subs) with Red filter (R).

3.56 hours (61x210s subs) with Green filter (G).

3.44 hours (59x210s subs) with Blue filter (B).

Atmospheric conditions:

The shown image was developed from data acquired in a Bortle Class 8 area (i.e. in an environment experiencing a degree of light pollution typical of a city) where the sky quality during observation was such that both transparency (i.e. the level of atmospheric clarity) and seeing (i.e. the level of atmospheric turbulence) varied from average to below average.

Processed in PixInsight.

Preprocessing notes:

Created LRGB "masters" by Calibration, Cosmetic Correction, Weighted Subframes, Star Alignment, and Integration.

Postprocessing notes:

a. Dynamic Cropping of LRGB masters each to the same dimensions having a 3:2 aspect ratio.

b. Applied a Screen Transfer Function to view the resulting images.

c. For the L master: Applied a Dynamic Background Extractor and saved the settings to be used later when applying a DBE on the RGB masters.

d. Applied BlurXT and NoiseXT.

e. Applied a Histogram Transformation. This step generated a nonlinear image which was saved as a postprocessed L image.

f. "Built" a color image from the R, G and B masters by using LRGB Combination and applied a DBE to the color image using the same DBE settings as used for the L master.

g. Since a color image is involved, this necessitated the application of Background Neutralization and Color Calibration to the result from step f above.

h. Applied BlurXT, NoiseXT and a Histogram Transformation. Saved the nonlinear result as a postprocessed RGB image.

i. Used LRGB Combination to "apply" an instance from the postprocessed L image to the postprocessed RGB image.

j. Applied StarXterminator to create starless (i.e. containing the target image - in this case M51) and stars-only images.

k. Processed the starless image, after applying a range selection mask to protect the background area, using Local Histogram Equalization, Curves Transformation and Color Saturation. Curves Transformation was used only to boost the saturation whereas Color Saturation was used to enhance specific color hues.

l. Applied SCNR (Subtractive Chromatic Noise Reduction). Removed mask and used an expression in Pixel Math to combine the result from step k above with the stars-only image from step j.

m. As a final step, after protecting the target image with a Star Mask, applied a (star reduction) Morphological Transformation to the result from step l above.

Just as spring (in the Northern Hemisphere) is the best time for galaxies, summer is the best time for nebulae and star clusters. Two of the most famous nebulae are the Lagoon Nebula (at bottom, also known as M 8 or NGC 6523) and the Trifid Nebula (at the top right, aka M 20 or NGC 6514). You get glowing ionized hydrogen (pink). You get dust that is scattering starlight (blue). You get lanes of cold, dense dust that blocks the light of stars behind it. And if you have cold, dense dust, you get star formation. Some of the hottest, most massive stars visible to the naked eye are in these nebulae.

There is something else interesting about how they are aligned with our view from the solar system. The plane of the ecliptic cuts right between them. This means that, as the Earth travels around the Sun, the Sun appears to pass almost through the middle of this picture. It does so one day after the southernmost solstice. See, I didn't want to say "winter solstice" because of the whole Northern vs. Southern Hemisphere thing again. And, if you wait about 13,000 years, this passage will take place around the northernmost solstice due to Earth's cycle of precession.

Either way, enjoy the view!

Over a course of 4 separate nights in the summers of 2017 and 2018, I took 10 separate tiles to make this mosaic. All subframes are 2 minute exposures with a Celestron Edge HD 9.25" at f/2.3 with HyperStar and an Atik 314L+ color CCD camera. Preprocessing in Nebulosity; mosaic assembly and processing in PixInsight; final touches in PS CS 5.1.

The image center (J2000) is at:

RA 18h 4m 5s

DEC -23° 36' 13"

The image spans 1° 32' by 2° 5'.

I decided to continue this awesome galaxy, and try some new process on it. I think it is way better than the older images I was uploaded. It is near 7 hour of integration time with 5 min subs.

M: Skywatcher EQ-5 Pro GoTO

S: Lacerta 72/432 F6

R: Skywatcher 0,85x

C: Pentax K-1

G: Orion 50mm mini

GC: ZWO ASI 120mm Mini

Exposures:

Light: 79x300s, ISO800

Dark: 30, ISO800

Dark flat: 200, ISO800

Flat: 15, ISO800

- I'm in South Bohemia away from major cities and we had a cloudless night so I was really happy to be able to see the Milky way with my own eyes. Here is a test shot of the sky where the Milky way is seen across the sky from the treetops. I can see one other nebulous object here below our own galaxy, I don't know which Messier object that is so please comment if you recognise it.

Update: I'm now quite sure that nebulous object is in fact the Andromeda galaxy.

Taken with a TMB92L, Canon T3i DSLR, and Celestron CG-4 mount. Consists of 34 light and 20 dark frames, each a 45-second exposure at ISO 800, stacked in DeepSkyStacker and processed in Photoshop.

The Pleiades, also known as the Seven Sisters and Messier 45, are an open star cluster containing middle-aged, hot B-type stars in the north-west of the constellation Taurus. It is among the star clusters nearest to Earth, it is the nearest Messier object to Earth, and is the cluster most obvious to the naked eye in the night sky.

The cluster is dominated by hot blue and luminous stars that have formed within the last 100 million years. Reflection nebulae around the brightest stars were once thought to be left over material from the formation of the cluster, but are now considered likely to be an unrelated dust cloud in the interstellar medium through which the stars are currently passing.

Equipment:

Scope: Lacerta 72/432 F6 0.85x reduktorral (367mm F5.1)

Mount: Skywatcher EQ-5 Pro Synscan Goto

Guide scope: Orion 50mm mini

Guide camera: ZWO ASI120mm Mini

Main camera: ZWO ASI183MM-Pro cooled monochrome camera

Accessories:

ZWO ASIAIR Pro

ZWO EFW 8x1.25"

Lacerta Dew-heater 20cm

Lacerta Dew-heater 30cm

Programs:

PixInsight

Adobe Photoshop CC 2020

Details:

Camera temp: -15°C

Gain: 53

Astronomik L-3 UV-IR Block: 92x180s

Astronomik Deep-Sky R: 16x180s

Astronomik Deep-Sky G: 14x180s

Astronomik Deep-Sky B: 20x180s

I think I stopped the aperture down a bit too much on this one, causing the diffraction spikes around the Pleiades's brightest stars. Next time, I'll try f/5.6 or f/6.3.

Taken with a Sigma AF 70-300mm f/4-5.6 APO DG at 133mm and f/8, Canon T3i DSLR, and Celestron Advanced VX mount. Consists of 34 light and 30 dark frames, each a 90-second exposure at ISO 1600, and 21 flat frames. Captured with BackyardEOS, stacked in DeepSkyStacker, and processed in Photoshop.

Taken from Savannah Skies Observatory using a Canon EOS Ra and 400 mm lens.

LINK

Other images from this series:

1. M8 and M20: www.flickr.com/photos/jbrimacombe/51050919231/

2. M16: www.flickr.com/photos/jbrimacombe/51050319198/

3. NGC 6188: www.flickr.com/photos/jbrimacombe/51051043096/

4. M78: www.flickr.com/photos/jbrimacombe/51050317763/

5. Rho Ophiuchus: www.flickr.com/photos/jbrimacombe/51051288802/

6. Tarantula Nebula: www.flickr.com/photos/jbrimacombe/51051288607/

7. Vela SNR: www.flickr.com/photos/jbrimacombe/51050478748/

LATEST VERSION: flic.kr/p/2m9Ur8e

Messier 7 / M7 / NGC 6475 / The Ptolemy Cluster

NGC 6453

M7 is a bright, loose open cluster in the constellation of Scorpius. It is about 980 light-years away and it is estimated to be 200 million years old. From our perspective, M7 lies in front of the Galactic Center (the center of the Milky Way). As a result, the dense starfield behind this cluster is the richest of all Messier objects and one of the richest in the entire night sky.

NGC 6453 is a globular cluster about 38,000 light-years away. It is heavily obscured by interstellar dust since it lies behind the Galactic Center. The cluster appears as a golden clump between M7 and the left edge of the frame.

2 years ago, my first attempted deep-sky image featured M7: flic.kr/p/2a8e8s2

1 year ago, this was my much-improved result: flic.kr/p/2hc2S3M

Total integration: 16 hours 37.5 minutes (997.5 minutes)

06/22/19: 307 x 30 seconds ISO800

08/17/19: 62 x 60 seconds ISO200

08/19/19: 168 x 60 seconds ISO200

06/25/20: 90 x 120 seconds ISO200

06/28/20: 55 x 120 seconds ISO200

06/29/20: 94 x 120 seconds ISO200

07/14/20: 68 x 120 seconds ISO200

Location: Coral Springs, FL

SQM: 18.18 mag/arcsec^2 (Bortle 8/9)

Camera: Canon T3i (stock/unmodified)

Average camera temperature: 104 F (40 C)

Telescope: Explore Scientific ED80 f/6.0 Apochromatic Refractor (with ES field flattener)

Mount: Orion Sirius EQ-G

Guide scope: Svbony 50mm f/4.0 Guide Scope

Guide camera: Orion StarShoot AutoGuider

Software: N.I.N.A. with PlateSolve2 and PHD2

Pre-processed with PixInsight, processed with PixInsight and Paint.NET

🌌 M74 – The Phantom Galaxy 🔭✨

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www.instagram.com/ale_motta_astrofotografia

Behold Messier 74, a grand-design spiral galaxy located 32 million light-years away in the constellation Pisces. Its perfectly symmetric spiral arms, filled with newborn stars and glowing nebulae, make it one of the most stunning galaxies in the night sky.

📍 Constellation: Pisces ⛎

🌍 Distance: ~32 million light-years

💫 Type: Spiral Galaxy (SA(s)c)

🔭 Apparent Magnitude: 9.4

📏 Apparent Size: 10.5' × 9.5'

️ Coordinates (J2000): RA 01h 36m 41.8s | Dec +15° 47′ 01″

✨ Fun Facts:

M74 is known as the Phantom Galaxy due to its low surface brightness, making it a challenging target for amateur astronomers. 👻🔭

It harbors a supermassive black hole at its center, estimated to be 10 million times the mass of the Sun. ️💀

M74 has been home to several supernova explosions, including SN 2002ap, a rare hypernova event! 💥

A cosmic masterpiece of nature—who else finds spiral galaxies mesmerizing? 💫✨

Lights: 165x300" (LRGB)

Telescope: Officina Stellare ProRC 700

Camera: QHY 600M

Filters: LRGB Astrodon

Processed: Pixinsight

Date: 24/09/2023

This region is too large for me to build a mosaic from with my usual setup, so I thought I would try a deep dive into it with the DSLR. Near the center toward the top is the Butterfly Cluster (M6 or NGC 6405), and toward the lower left corner is Ptolemy's Cluster (M7 or NGC 6475). The bright stars in the lower right are Shaula and Lesath, which mark the end of the tail of Scorpius. The Milky Way is brightly visible to the naked eye through this part of its path, though the star clouds are more prominent in the left side of this image than the right. Infrared images of this region show that M6 lies closer to the plane of the dust disk of our galaxy. This is likely the reason for there appearing to be fewer stars in its vicinity - the more distant stars are obscured by more dust than those around M7. On the right edge of the image is the War and Peace Nebula (NGC 6357).

This is a stack of 39 42s tracked exposures with a Nikon D80 at ISO 3200 and 147 mm focal length. Tracking was done with an omegon MiniTrack LX2. Subframes were preprocessed, combined, and processed in PixInsight. Additional work was done with Photoshop.

M81 is a large spiral galaxy in Ursa Major that is reasonably local to us at 12 million light years. Its companion, M82 has been disrupted by an encounter with M81 in the past.

M82 is a starburst galaxy with intense star formation triggered by the gravitational influence of M81. The red fan-like filaments at right angles to the axis of the galaxy are formed by a "superwind". The intense star formation has resulted in multiple supernovae explosions occurring about once every 10 years - the explosions power the super wind. The filaments are expanding outwards at about 600 miles a second and glow brightly in hydrogen alpha (red). They are also a very strong source of radio emission, listed as 3C 231 in the 3rd Cambridge catalogue of radio sources.

I tried imaging the last supernova in M82- SN 2014J (Class 1a) in 2014 when I was just starting astrophotography. I think I just used a single 30 second exposure on a 300mm lens - not convinced I caught anything!

M82 is listed by itself in the Arp catalogue of peculiar galaxies as Arp 337. The pair (M81 and M82) are also listed in the paired galaxies section of the Arp catalogue.

A very, very faint patch of blue between 3 triangular stars under M81 is Holmberg IX - a small irregular dwarf galaxy under the gravitational influence of M81 - a bit like our Magellanic Clouds.

Sky and Telescope Magazine have some bonus digital content attached to their May 2016 edition that goes deep into M81 and M82 listing regions containing HII zones, SNR and radio/X-ray sources. I can just about pick out some of the main zones they mention at 200% magnification in Photoshop.

M82 contains a faint arrowhead pointing to the superwinds. This is composed of 4 brownish dots - regions A,C,D and E that each contain many Radio and X-ray sources, Massive star clusters and SNRs - these are some of the regions producing the superwinds from frequent massive SN explosions.

Its easier to pick out the listed regions in M81 and I can locate A through to G. A to D are bright HII regions. Eand F are listed as containing star cluster/globular cluster - somewhat humbling to be able to detect star clusters or globular clusters around a distant galaxy from a small backyard scope.

There are lots of good star clusters in Scutum. Although M26 is smaller in angular size that nearby M11, it still stands out from the dense background of stars. Shooting from dark skies allowed me to boost the background stars to show where dark molecular clouds are relative to the cluster.

This is a stack of 56 40 s exposures with a Celestron Edge HD 925 at f/2.3 with HyperStar and an Atik 314L+ color CCD camera. Preprocessing in Nebulosity; all other processing in PixInsight.

North is at the top and east at the left in this image.