View allAll Photos Tagged planetarynebula
Processed version of an image from the Hubble Space Telescope of NGC 6818, a planetary nebula called the Little Gem Nebula.
Original caption: This colourful bubble is a planetary nebula called NGC 6818, also known as the Little Gem Nebula. It is located in the constellation of Sagittarius (The Archer), roughly 6000 light-years away from us. The rich glow of the cloud is just over half a light-year across — humongous compared to its tiny central star — but still a little gem on a cosmic scale. When stars like the Sun enter retirement, they shed their outer layers into space to create glowing clouds of gas called planetary nebulae. This ejection of mass is uneven, and planetary nebulae can have very complex shapes. NGC 6818 shows knotty filament-like structures and distinct layers of material, with a bright and enclosed central bubble surrounded by a larger, more diffuse cloud. Scientists believe that the stellar wind from the central star propels the outflowing material, sculpting the elongated shape of NGC 6818. As this fast wind smashes through the slower-moving cloud it creates particularly bright blowouts at the bubble’s outer layers. Hubble previously imaged this nebula back in 1997 with its Wide Field Planetary Camera 2, using a mix of filters that highlighted emission from ionised oxygen and hydrogen (opo9811h). This image, while from the same camera, uses different filters to reveal a different view of the nebula. A version of the image was submitted to the Hubble’s Hidden Treasures image processing competition by contestant Judy Schmidt.
This is a super clear image of tiny planetary nebula Henize 2-138. The central star looks a little strange.
Data used: hst_06353_15_wfpc2_total_pc
A beautiful, small planetary nebula captured by Hubble only through F656N. I'm really curious about what this nebula would look like in colour.
This image was enlarged to 150% original size. I don't really want to enlarge any images to more than that.
Data used: hst_06353_29_wfpc2_f656n_pc
Gemini image of the planetary nebula NGC 246, the Skull Nebula.
Image source: Gemini/AURA (and modified by me)
Edited Hubble Space Telescope image of the Butterfly Nebula.
Original caption: Hubble was recently retrained on NGC 6302, known as the "Butterfly Nebula," to observe it across a more complete spectrum of light, from near-ultraviolet to near-infrared, helping researchers better understand the mechanics at work in its technicolor "wings" of gas. The observations highlight a new pattern of near-infrared emission from singly ionized iron, which traces an S shape from lower left to upper right. This iron emission likely traces the central star system ís most recent ejections of gas, which are moving at much faster speeds than the previously expelled mass.
The star or stars at its center are responsible for the nebula's appearance. In their death throes, they have cast off layers of gas periodically over the past couple thousand years. The "wings" of NGC 6302 are regions of gas heated to more than 36,000 degrees Fahrenheit that are tearing across space at more than 600,000 miles an hour.
NGC 6302 lies between 2,500 and 3,800 light-years away in the constellation Scorpius.
Edited Spitzer Space Telescope image of the Helix Nebula. Color/processing variant.
Original caption: A dying star is throwing a cosmic tantrum in this combined image from NASA's Spitzer Space Telescope and the Galaxy Evolution Explorer (GALEX), which NASA has lent to the California Institute of Technology in Pasadena. In death, the star's dusty outer layers are unraveling into space, glowing from the intense ultraviolet radiation being pumped out by the hot stellar core.
This object, called the Helix nebula, lies 650 light-years away, in the constellation of Aquarius. Also known by the catalog number NGC 7293, it is a typical example of a class of objects called planetary nebulae. Discovered in the 18th century, these cosmic works of art were erroneously named for their resemblance to gas-giant planets.
Planetary nebulae are actually the remains of stars that once looked a lot like our sun. These stars spend most of their lives turning hydrogen into helium in massive runaway nuclear fusion reactions in their cores. In fact, this process of fusion provides all the light and heat that we get from our sun. Our sun will blossom into a planetary nebula when it dies in about five billion years.
When the hydrogen fuel for the fusion reaction runs out, the star turns to helium for a fuel source, burning it into an even heavier mix of carbon, nitrogen and oxygen. Eventually, the helium will also be exhausted, and the star dies, puffing off its outer gaseous layers and leaving behind the tiny, hot, dense core, called a white dwarf. The white dwarf is about the size of Earth, but has a mass very close to that of the original star; in fact, a teaspoon of a white dwarf would weigh as much as a few elephants!
The glow from planetary nebulae is particularly intriguing as it appears surprisingly similar across a broad swath of the spectrum, from ultraviolet to infrared. The Helix remains recognizable at any of these wavelengths, but the combination shown here highlights some subtle differences.
The intense ultraviolet radiation from the white dwarf heats up the expelled lay
There's definitely a much better way to do this, but I don't know it yet. I haven't tried combining narrowband and wideband data before.
This nebula was imaged for proposals 6119 & 8307.
150% original size.
North is up.
Red: hst_06119_36_wfpc2_f814w_pc + hst_08307_01_wfpc2_f658n_pc
Green: hst_08307_01_wfpc2_f656n_pc
Blue: hst_06119_36_wfpc2_f555w_pc + hst_08307_01_wfpc2_f502n_pc
Gemini Observatory image of Kronberger 61 showing the ionized shell of expelled gas resembling a soccer ball. The light of the nebula is primarily due to ionized oxygen (oxygen-III) emission and its central star can be seen as the slightly bluer star very close to the center of the nebula. The field of view is 2.2 x 3.4 arcminutes with north up (rotated 22 degrees west of north). Image processing by Travis Rector, University of Alaska Anchorage. A color composite image, it consists of two narrow-band images (O-III and Hydrogen-alpha with three, 500-second integrations each) obtained with the Gemini Multi-Object Spectrograph (GMOS) on the Gemini North telescope on Mauna Kea in Hawaiâi. Below the bright star at left is a barred spiral galaxy in the distant background, careful inspection will reveal several additional distant galaxies in the image.
PK 352-7.1
Planetary nebula in Corona Australis.
Source: Hubble Legacy Archive
hst_08345_13_wfpc2_f656n_pc
hst_08345_13_wfpc2_f658n_pc
Edited Spitzer Space Telescope image of the Helix Nebula. Color/processing variant.
Original caption: A dying star is throwing a cosmic tantrum in this combined image from NASA's Spitzer Space Telescope and the Galaxy Evolution Explorer (GALEX), which NASA has lent to the California Institute of Technology in Pasadena. In death, the star's dusty outer layers are unraveling into space, glowing from the intense ultraviolet radiation being pumped out by the hot stellar core.
This object, called the Helix nebula, lies 650 light-years away, in the constellation of Aquarius. Also known by the catalog number NGC 7293, it is a typical example of a class of objects called planetary nebulae. Discovered in the 18th century, these cosmic works of art were erroneously named for their resemblance to gas-giant planets.
Planetary nebulae are actually the remains of stars that once looked a lot like our sun. These stars spend most of their lives turning hydrogen into helium in massive runaway nuclear fusion reactions in their cores. In fact, this process of fusion provides all the light and heat that we get from our sun. Our sun will blossom into a planetary nebula when it dies in about five billion years.
When the hydrogen fuel for the fusion reaction runs out, the star turns to helium for a fuel source, burning it into an even heavier mix of carbon, nitrogen and oxygen. Eventually, the helium will also be exhausted, and the star dies, puffing off its outer gaseous layers and leaving behind the tiny, hot, dense core, called a white dwarf. The white dwarf is about the size of Earth, but has a mass very close to that of the original star; in fact, a teaspoon of a white dwarf would weigh as much as a few elephants!
The glow from planetary nebulae is particularly intriguing as it appears surprisingly similar across a broad swath of the spectrum, from ultraviolet to infrared. The Helix remains recognizable at any of these wavelengths, but the combination shown here highlights some subtle differences.
The intense ultraviolet radiation from the white dwarf heats up the expelled lay
This is a very stunning planetary nebula and it makes me wonder how many are still waiting to be found in the archive. Hundreds? It looks like this one had multiple outbursts which would explain that gorgeous chaotic appearance. Also that arc to the left is pretty interesting. I really hope I got the filters right on this one, I kept second-guessing myself, but I think this was the best result. This is the first time I can think of where the WFC3/UVIS instrument was used to conduct a planetary nebula survey. I really need to focus on my school work now, so I think this will be the last one for a while.
Red: hst_11657_80_wfc3_uvis_f814w
Green: hst_11657_80_wfc3_uvis_f350lp
Blue: hst_11657_80_wfc3_uvis_f200lp + hst_11657_80_wfc3_uvis_f502n
Equipment: Nikon D5300, Tamron SP 70-300mm f/4-5.6 Di VC USD lens, and iOptron Skytracker. Taken at 300mm, f/8.0, ISO 8000, 49 frames of 60 seconds each plus 30 darks. Stacked in Regim and cropped/processed in Lightroom.
M27 Dumbell Nebula-2012.09.05-Canon EOS450D-11.5mins-ISO 1600-16 subs-DSS-Gimp2.8-Neat Image. This set of exposures were taken with the camera piggy backed on my telescope.
This is yet another beautiful planetary nebula and I really like the halo-ish concentric-ish rings around it. It also has quite an interesting shape.
North is up and this image is of original size.
Red: F656N
Green: No layer used
Blue: F658N
Finally having some good success with autoguiding my C6.
M27 - The Dumbbell nebula
C6S-GT at F10, 8x3min, Canon 30D at ISO 1600
Guided with a DSI Pro and PHD guiding.
Combination of Hubble Space Telescope and Chandra Space Telescope images showing the planetary nebula NGC 2392. The pink region in the center is from the Chandra image (which shows x-rays).
A very tiny bipolar planetary nebula.
These data were collected for proposal 8345
This image was enlarged to 150% its original size.
Red: hst_08345_31_wfpc2_f658n_pc
Green: pseudo
Blue: hst_08345_31_wfpc2_f656n_pc
Another night of data added, bringing the total number of subframes up to 29.
This larger number of lights has helped smooth out the background. It's also helped identify the problem areas with other lights and the library of darks. The amp glow in the northern section of the frame comes from bad darks. I'll have to make a few new ones that match the temperature range of 14-17 C. Also, there were light leaks getting in on some of the subs, causing large arcs to streak across the field.
I did a little different processing on this image to try to get more from the better data. I applied a curve to the image after DBE and masked stretch. There were two curves - one for RGB and another for L. The L curve was a little hotter, bringing up some lightness of small stars. I also added some passes of sharpening and better noise reduction.
As usual, I brought the tif files into LR for a final tweak before uploading.
Here's the output from the PI image solve:
Referentiation Matrix (Gnomonic projection = Matrix * Coords[x,y]):
+0.000024749075 +0.000225128501 -0.276575132022
-0.000225173446 +0.000024803937 +0.373822748842
+0.000000000000 +0.000000000000 +1.000000000000
Resolution ........ 0.815 arcsec/pix
Rotation .......... -96.275 deg
Focal ............. 1365.93 mm
Pixel size ........ 5.40 um
Field of view ..... 48' 13.2" x 28' 5.5"
Image center ...... RA: 18 53 23.314 Dec: +32 56 18.62
Image bounds:
top-left ....... RA: 18 52 03.888 Dec: +33 18 42.78
top-right ...... RA: 18 52 29.592 Dec: +32 30 47.60
bottom-left .... RA: 18 54 17.556 Dec: +33 21 48.19
bottom-right ... RA: 18 54 42.072 Dec: +32 33 51.34
Location: Long Island, NY
Camera: Hutech modified Canon T3i
Telescope: Celestron Ultima 8 with PEC.
Image details: 12x30s (6 minutes), no dark or flat frames.
Acquired using an ASIAir to control tracking and exposures.
Processed with Pixinsight and GIMP.
This wideband data was not collected with the intent of seeing the nebulosity, but instead the binary central star. This means that there are quite a few ground-based images which are much clearer in seeing the nebula as a whole. However, the data does provide some interesting detail in its very tight frame. Since this was a rather dull two-colour image, I added some ground-based data for colour enhancement. I hope that's ok. I could have manipulated it to match, but I thought that would probably be even worse.
M76 is most commonly referred to as the Little Dumbbell Nebula, named for its supposed resemblance to the much larger Dumbbell Nebula. This one isn't exactly a hidden treasure, it was published for a collection of the Hubble's observations of Messier objects. Still, I thought it deserved more attention and, of course, I am skipping none.
Note: saturation was very slightly increased
See the Hubble-only version here.
Luminosity+Colour:
Red: WFPC2 F814W
Green: pseudo
Blue: WFPC2 F555W
+ Colour:
Mount Lemmon Sky Centre (already processed by Adam Block)
The ring nebula, or M57 to astrogeeks, is a planetary nebula. This is a medium-sized dying star's last throws, as it expells gas and collapses on itself to become a white dwarf. The dying star can just be seen in the middle of the nebula. This process will happen to our sun in a few billion years. Taken unguided through a Celestron 14" telescope on a Software Bisque mount with a modified Canon 450D, with about 21 minutes total exposure. A friend of mine has access to an academic observatory, and she is nice enough to let me in and fire up the scope for me from time to time! Thanks Jaz! It's an amazing piece of equipment and so much fun to use!
This NASA Hubble Space Telescope image shows one of the most complex planetary nebulae ever seen, NGC 6543, nicknamed the "Cat's Eye Nebula." Hubble reveals surprisingly intricate structures including concentric gas shells, jets of high-speed gas and unusual shock-induced knots of gas. Estimated to be 1,000 years old, the nebula is a visual "fossil record" of the dynamics and late evolution of a dying star. A preliminary interpretation suggests that the star might be a double-star system. The suspected companion star also might be responsible for a pair of high-speed jets of gas that lie at right angles to this equatorial ring. If the companion were pulling in material from a neighboring star, jets escaping along the companion's rotation axis could be produced. These jets would explain several puzzling features along the periphery of the gas lobes. Like a stream of water hitting a sand pile, the jets compress gas ahead of them, creating the "curlicue" features and bright arcs near the outer edge of the lobes. The twin jets are now pointing in different directions than these features. This suggests the jets are wobbling, or precessing, and turning on and off episodically. This color picture, taken with the Wide Field Planetary Camera-2, is a composite of three images taken at different wavelengths. (red, hydrogen-alpha; blue, neutral oxygen, 6300 angstroms; green, ionized nitrogen, 6584 angstroms). The image was taken on September 18, 1994. NGC 6543 is 3,000 light- years away in the northern constellation Draco. The term planetary nebula is a misnomer; dying stars create these cocoons when they lose outer layers of gas. The process has nothing to do with planet formation, which is predicted to happen early in a star's life.
The Dumbbell Nebula (also known as Apple Core Nebula, Messier 27, M 27, or NGC 6853) is a planetary nebula in the constellation Vulpecula, at a distance of about 1,360 light years.
Taken with 14.5" f7.0 RCOS telescope mounted on a Paramount ME, FLI PL16K camera at -35C, 80 mins of RGB, 150 mins of Luminance.
6 usable lights (60s), 10 darks, 20 flats, 20 bias. Canon EOS 450D DSLR prime focus, ISO1600. Baader Neodymium filter and coma corrector. Sky-Watcher 150P Explorer on EQ3-2 mount. DeepSkyStacker > PixInsight > PhotoShop.
This is M20, the Trifid Nebula. It's interesting because the pink and blue colors are very distinct when imaging this target. This lies in the dense star fields of Sagittarius and lies close by to M8, the Lagoon Nebula, and at the top of the image, M21, which got cut off when I cropped it. This is a result of over 30 minutes of exposures.
06/16/12
Joshua Tree National Park, CA
70 frames = 31 min 58 second exposure ISO 6400
Processed in DeepSkyStacker and Gimp 2
6" Meade Newtonian Reflector LXD75 EQ Mount
Canon Rebel T3 DSLR
Canon EOS 450D 20x 20s subs ISO800 Prime focus Skywatcher 150 Explorer Newtonian. Processed in DeepSkyStacker, PixInsight and Photoshop CS5
a very faint eso nebula, but none shall be intentionally skipped. it has a pretty interesting structure.
red: vlt/fors2 h_alpha
green: pseudo
blue: vlt/fors2 oiii
This small and unspectacular planetary nebula is still a planetary nebula, so I just had to process it.
North is up and the image is of original size.
Red: F656N
Green: No layer used
Blue: F658N
A small, but intricate, planetary nebula. I like this one. Being so small, it has not been studied very much and therefore there is not much information surrounding it, as with many of the other small objects.
North is up and the image is of original size.
Red: F656N
Green: No filter used
Blue: F658N
Equipment: Nikon D5300, Tamron SP 70-300mm f/4-5.6 Di VC USD lens, and iOptron Skytracker. Taken at 300mm, f/8.0, ISO 8000, 121 frames of 30 seconds each plus 60 darks. Stacked in Regim and cropped/processed in Lightroom.
Edited Hubble Space Telescope image of the nebula IC 4634. Color/processing variant.
Original caption: This striking Hubble image of the planetary nebula IC 4634 reveals two shining, S-shaped ejections from a dying star. This star, awash in glowing material at the centre of the picture, bloated as it aged and launched its outer layers off into space. The star’s very hot, exposed core has since beamed intense ultraviolet radiation at these lost shells of gas, making them glow in rich colours. This process has been far from orderly or calm, however, as revealed by the distinct, separate waves of thrown-off gases. One is more distant and therefore was spewed first, followed by a more recently ejected tide of matter that formed the tighter S-shape. The result is remarkably symmetric on each side of the central star. The NASA/ESA Hubble Space Telescope’s Wide Field Planetary Camera 2 (WFPC2) captured this image of IC 4634, which is found more than about 7500 light-years away in the constellation of Ophiuchus (the Serpent Holder). IC 4634 and other objects like it are known as planetary nebulae due to their appearance through early telescopes as rounded, faintly luminous discs similar to the distant planets Uranus and Neptune. The picture was created from images through five different filters (F487N, F502N, F574M, F656N and F658N) that captured light emitted by different elements in the gaseous features. The total aggregate exposure time was 4000 seconds and the field of view is just 29 arcseconds across.
Jones-Emberson 1 (PK 164+31.1) is a 14th magnitude planetary nebula in the constellation Lynx at a distance of 1600 light years. It is a larger planetary with low surface brightness. The 16.8-magnitude central star is very blue white dwarf.
Sadly I don't think I will be adding the OIII here.
SII is apparently very low...
Some flexure persists,and a breeze does not help this large tube
Linear NR, but Decon applied to stretched image...very low snr
28x900 seconds (bin 2)
12" f/4.6 Newtonian
ST10@-20C
Pixinsight
Recent previous attempt (Celestron 25 cm)
www.flickr.com/photos/daveh56/6820770263/in/photostream
Nice HaLRGB and more info here;
Another (pre?)planetary nebula. Not the most visually appealing, but hey, it's bipolar and I haven't seen it before. The ACS' HRC seems to take lovely pictures of super bright objects, but when it comes to darker ones it gets pretty noisy. I guess the culprit would be exposure time. F814W ended up being especially noisy.
These data were collected as part of proposal 9463: Are OH/IR stars the youngest post-AGB stars?
Red: hst_9463_58_acs_hrc_f814w
Green: pseudo
Blue: hst_9463_58_acs_hrc_f606w
Edited Spitzer Space Telescope image of the Helix Nebula. Color/processing variant.
Original caption: A dying star is throwing a cosmic tantrum in this combined image from NASA's Spitzer Space Telescope and the Galaxy Evolution Explorer (GALEX), which NASA has lent to the California Institute of Technology in Pasadena. In death, the star's dusty outer layers are unraveling into space, glowing from the intense ultraviolet radiation being pumped out by the hot stellar core.
This object, called the Helix nebula, lies 650 light-years away, in the constellation of Aquarius. Also known by the catalog number NGC 7293, it is a typical example of a class of objects called planetary nebulae. Discovered in the 18th century, these cosmic works of art were erroneously named for their resemblance to gas-giant planets.
Planetary nebulae are actually the remains of stars that once looked a lot like our sun. These stars spend most of their lives turning hydrogen into helium in massive runaway nuclear fusion reactions in their cores. In fact, this process of fusion provides all the light and heat that we get from our sun. Our sun will blossom into a planetary nebula when it dies in about five billion years.
When the hydrogen fuel for the fusion reaction runs out, the star turns to helium for a fuel source, burning it into an even heavier mix of carbon, nitrogen and oxygen. Eventually, the helium will also be exhausted, and the star dies, puffing off its outer gaseous layers and leaving behind the tiny, hot, dense core, called a white dwarf. The white dwarf is about the size of Earth, but has a mass very close to that of the original star; in fact, a teaspoon of a white dwarf would weigh as much as a few elephants!
The glow from planetary nebulae is particularly intriguing as it appears surprisingly similar across a broad swath of the spectrum, from ultraviolet to infrared. The Helix remains recognizable at any of these wavelengths, but the combination shown here highlights some subtle differences.
The intense ultraviolet radiation from the white dwarf heats up the expelled lay
Camera: Nikon D50
Exposure: 1hr 9m (23 frames) ISO 800 RGB
Filter: Orion Skyglow Imaging Filter
Focus Method: Prime focus
Telescope Aperature/Focal Length: 203×812mm
Mount: LXD75
Telescope: Meade 8" Schmidt-Newtonian
Guided: Yes - PHD Guiding
Stacked: DeepSkyStacker
Adjustments: cropped/leveled in Photoshop
Location: Flintstone, GA
Edited Chandra Space Telescope x-ray image of the Crab Nebula and how it looks optically, superimposed.
Original caption: In commemoration of the 15th anniversary of NASA's Chandra X-ray Observatory, four newly processed images of supernova remnants dramatically illustrate Chandra's unique ability to explore high-energy processes in the cosmos. The images of the Tycho and G292.0+1.8 supernova remnants show how Chandra can trace the expanding debris of an exploded star and the associated shock waves that rumble through interstellar space at speeds of millions of miles per hour. The images of the Crab Nebula and 3C58 show how extremely dense, rapidly rotating neutron stars produced when a massive star explodes can create clouds of high-energy particles light years across that glow brightly in X-rays.
Thought the last one was gross? The Hubble just barely detected the nebulosity of this planetary nebula with these rather short exposures, which is why it appears so dark. This data was collected to specifically study the central star, not the nebula itself. This is one of the worse things in the archive, but at least you can see something. This isn't a hidden treasure by any means.
There are much better amateur observations of this nebula if pretty pictures are the priority.
Red: WFPC2 F814W
Green: pseudo
Blue: WFPC2 F555W
Edited European Southern Observatory image of the planetary nebula (called a "spare tyre" by the observatory) IC 5148. Color/processing variant.
Original caption: IC 5148 is a beautiful planetary nebula located some 3000 light-years away in the constellation of Grus (The Crane). The nebula has a diameter of a couple of light-years, and it is still growing at over 50 kilometres per second — one of the fastest expanding planetary nebulae known. The term “planetary nebula” arose in the 19th century, when the first observations of such objects — through the small telescopes available at the time — looked somewhat like giant planets. However, the true nature of planetary nebulae is quite different. When a star with a mass similar to or a few times more than that of our Sun approaches the end of its life, its outer layers are thrown off into space. The expanding gas is illuminated by the hot remaining core of the star at the centre, forming the planetary nebula, which often takes on a beautiful, glowing shape. When observed with a smaller amateur telescope, this particular planetary nebula shows up as a ring of material, with the star — which will cool to become a white dwarf — shining in the middle of the central hole. This appearance led astronomers to nickname IC 5148 the Spare Tyre Nebula. The ESO Faint Object Spectrograph and Camera (EFOSC2) on the New Technology Telescope at La Silla gives a somewhat more elegant view of this object. Rather than looking like a spare tyre, the nebula resembles ethereal blossom with layered petals.
Processed version of an image from the Hubble Space Telescope of NGC 6818, a planetary nebula called the Little Gem Nebula.
Original caption: This colourful bubble is a planetary nebula called NGC 6818, also known as the Little Gem Nebula. It is located in the constellation of Sagittarius (The Archer), roughly 6000 light-years away from us. The rich glow of the cloud is just over half a light-year across — humongous compared to its tiny central star — but still a little gem on a cosmic scale. When stars like the Sun enter retirement, they shed their outer layers into space to create glowing clouds of gas called planetary nebulae. This ejection of mass is uneven, and planetary nebulae can have very complex shapes. NGC 6818 shows knotty filament-like structures and distinct layers of material, with a bright and enclosed central bubble surrounded by a larger, more diffuse cloud. Scientists believe that the stellar wind from the central star propels the outflowing material, sculpting the elongated shape of NGC 6818. As this fast wind smashes through the slower-moving cloud it creates particularly bright blowouts at the bubble’s outer layers. Hubble previously imaged this nebula back in 1997 with its Wide Field Planetary Camera 2, using a mix of filters that highlighted emission from ionised oxygen and hydrogen (opo9811h). This image, while from the same camera, uses different filters to reveal a different view of the nebula. A version of the image was submitted to the Hubble’s Hidden Treasures image processing competition by contestant Judy Schmidt.
Edited Hubble Space Telescope image of the planetary nebula NGC 7027. Color/processing variant.
Original caption: Recently, NGC 7027's central star was identified in a new wavelength of light ó near-ultraviolet ó for the first time by using Hubble's unique capabilities. The near-ultraviolet observations will help reveal how much dust obscures the star and how hot the star really is.
This object, which resembles a colorful jewel bug, is a visibly diffuse region of gas and dust that may be the result of ejections by closely orbiting binary stars that were first slowly sloughing off material over thousands of years, and then entered a phase of more violent and highly directed mass ejections. Hubble first looked at this planetary nebula in 1998. By comparing the old and new Hubble observations, researchers now have additional opportunities to study the object as it changes over time.
Planetary nebulas are expanding shells of gas created by dying stars that are shedding their outer layers. When new ejections encounter older ejections, the resulting energetic collisions shape the nebula. The mechanisms underlying such sequences of stellar mass expulsion are far from fully understood, but researchers theorize that binary companions to the central, dying stars play essential roles in shaping them.
NGC 7027 is approximately 3,000 light-years away in the constellation Cygnus.
Edited Spitzer Space Telescope image of the Helix Nebula. Color/processing variant.
Original caption: A dying star is throwing a cosmic tantrum in this combined image from NASA's Spitzer Space Telescope and the Galaxy Evolution Explorer (GALEX), which NASA has lent to the California Institute of Technology in Pasadena. In death, the star's dusty outer layers are unraveling into space, glowing from the intense ultraviolet radiation being pumped out by the hot stellar core.
This object, called the Helix nebula, lies 650 light-years away, in the constellation of Aquarius. Also known by the catalog number NGC 7293, it is a typical example of a class of objects called planetary nebulae. Discovered in the 18th century, these cosmic works of art were erroneously named for their resemblance to gas-giant planets.
Planetary nebulae are actually the remains of stars that once looked a lot like our sun. These stars spend most of their lives turning hydrogen into helium in massive runaway nuclear fusion reactions in their cores. In fact, this process of fusion provides all the light and heat that we get from our sun. Our sun will blossom into a planetary nebula when it dies in about five billion years.
When the hydrogen fuel for the fusion reaction runs out, the star turns to helium for a fuel source, burning it into an even heavier mix of carbon, nitrogen and oxygen. Eventually, the helium will also be exhausted, and the star dies, puffing off its outer gaseous layers and leaving behind the tiny, hot, dense core, called a white dwarf. The white dwarf is about the size of Earth, but has a mass very close to that of the original star; in fact, a teaspoon of a white dwarf would weigh as much as a few elephants!
The glow from planetary nebulae is particularly intriguing as it appears surprisingly similar across a broad swath of the spectrum, from ultraviolet to infrared. The Helix remains recognizable at any of these wavelengths, but the combination shown here highlights some subtle differences.
The intense ultraviolet radiation from the white dwarf heats up the expelled lay
Because the color is somewhat distracting, this is a grayscale version of just the infrared data. I think the structure is most clearly visible in this single channel, monotone version.
Note at the nucleus of the nebula are some extra rings or arcs that are quite difficult to see in the color version.
I removed the diffraction spikes once again because they were very distracting and easy to confuse with the structure of the object.
Data from following proposal was used to create the image:
Characterization of the WFC3 IR Grisms
The filter represented here is WFC3/IR F140W
North is up.
I reworked the source files from this image and did a 2x drizzle with a crop in DSS. You can see more about this object at Wikipedia.
Note how the upper right area has some problems with alignment. This was because I wasn't aware of how important doing the drift alignment with all the equipment attached can be. Over the course of the series of exposures, there was field rotation and this appears as blurred stars. Remember, this is a half-size crop of the APS-C sensor. Imagine what it would be like with a Full Frame sensor! Also, the drizzle option seems to have added some strange "rings" around some of the brighter stars.
This is about 1 hour of lights with a ton of darks that have been accumulated over time.
I did a gradient subtraction, histogram stretching, and curves. I didn't see the need to do noise reduction as the image looks pretty good to me at the moment. PP with PixInsight LE.
Taken with the Pentax K10D and the Stellarvue SV4 scope at prime focus.
Here are the DSS settings:
Stacking mode: Custom Rectangle
Alignment method: Automatic
Drizzle x2 enabled
Cosmetic applied to hot pixels (Filter = 1 px, Detection Threshold = 99.0%)
Cosmetic applied to cold pixels (Filter = 1 px, Detection Threshold = 1.0%)
Stacking step 1 ->5 frames (ISO: 1600) - total exposure: 30 mn 4 s
RGB Channels Background Calibration: Yes
Per Channel Background Calibration: No
Method: Median
-> Offset: 24 frames (ISO: 1600) exposure: 1/4000 s
Method: Median Kappa-Sigma (Kappa = 2.00, Iterations = 5)
-> Dark: 16 frames (ISO : 1600) exposure: 6 mn 2 s
Method: Median Kappa-Sigma (Kappa = 2.00, Iterations = 5)
-> Dark Flat: 72 frames (ISO : 1600) exposure: 1/4000 s
Method:
Median Kappa-Sigma (Kappa = 2.00, Iterations = 5)
-> Flat: 24 frames (ISO: 1600) exposure: 1/4000 s
Method: Median Kappa-Sigma (Kappa = 2.00, Iterations = 5)
Stacking step 2 ->0 frames (ISO: 1600) - total exposure: -
RGB Channels Background Calibration: Yes
Per Channel Background Calibration: No
-> Offset: 24 frames (ISO: 1600) exposure: 1/4000 s
Method: Median Kappa-Sigma (Kappa = 2.00, Iterations = 5)
-> Dark: 30 frames (ISO : 1600) exposure: 30 s
Method: Median Kappa-Sigma (Kappa = 2.00, Iterations = 5)
-> Dark Flat: 72 frames (ISO : 1600) exposure: 1/4000 s
Method:
Median Kappa-Sigma (Kappa = 2.00, Iterations = 5)
-> Flat: 24 frames (ISO: 1600) exposure: 1/4000 s
Method: Median Kappa-Sigma (Kappa = 2.00, Iterations = 5)
Another night of data added, bringing the total number of subframes up to 29.
This larger number of lights has helped smooth out the background. It's also helped identify the problem areas with other lights and the library of darks. The amp glow in the northern section of the frame comes from bad darks. I'll have to make a few new ones that match the temperature range of 14-17 C. Also, there were light leaks getting in on some of the subs, causing large arcs to streak across the field.
I did a little different processing on this image to try to get more from the better data. I applied a curve to the image after DBE and masked stretch. There were two curves - one for RGB and another for L. The L curve was a little hotter, bringing up some lightness of small stars. I also added some passes of sharpening and better noise reduction.
As usual, I brought the tif files into LR for a final tweak before uploading.
Here's the output from the PI image solve:
Referentiation Matrix (Gnomonic projection = Matrix * Coords[x,y]):
+0.000024749075 +0.000225128501 -0.276575132022
-0.000225173446 +0.000024803937 +0.373822748842
+0.000000000000 +0.000000000000 +1.000000000000
Resolution ........ 0.815 arcsec/pix
Rotation .......... -96.275 deg
Focal ............. 1365.93 mm
Pixel size ........ 5.40 um
Field of view ..... 48' 13.2" x 28' 5.5"
Image center ...... RA: 18 53 23.314 Dec: +32 56 18.62
Image bounds:
top-left ....... RA: 18 52 03.888 Dec: +33 18 42.78
top-right ...... RA: 18 52 29.592 Dec: +32 30 47.60
bottom-left .... RA: 18 54 17.556 Dec: +33 21 48.19
bottom-right ... RA: 18 54 42.072 Dec: +32 33 51.34