December 29, 2010

PK219+31.1 or Abell 31 (12-26-2010)

This planetary nebula in Cancer was discovered by George Abell on photographic plates in 1955. It is very dim. Folks with very large amateur telescopes and special filters have trouble seeing it with their eyes. The nebula is relatively nearby, just 1863 light years, give or take 80 or so. Citation. It appears to be interacting with interstellar matter (just my guess), which gives the left side a bow-front or bow-shock look, while the right side trails off; perhaps the nebula is relatively old or weak. Other images show a significant OIII glow near the center. The brightest star in this image, at lower right, is 8.51. A few stars are between 9 and 10, and all others are magnitude 10 or dimmer. The dimmest stars in the image are less than magnitude 17. Here are links to my favorite images of Abell 31: here and here. This image is 14x10' with the Atik 16.

Here is a view with color. In this edition, the nebula has been colored red, the natural color of the Ha emission recorded above. The stars have been left white.

December 28, 2010

NGC 2174, the Monkey Head Nebula (12-26-10)

This is a better set of data than my first set on this object, which was slightly out of focus. This set is 14x8' with the Atik 16 through an Astronomik 12nm Ha filter and the Orion 120mm achromat w/WO 0.8x II ff/fr (f/4). Perhaps it's time to collect the other narrowband wavelengths.

December 23, 2010

Christmas Tree Cluster (12-23-2010)

Merry Christmas, everyone!

Of course, there is a reason this cluster is called the Christmas Tree Cluster, NGC 2264. The nebula behind it might be called the Christmas Tree Nebula as well. The brighter parts of the nebula have the shape of a Christmas tree, probably as a result of radiation from cluster stars. Just above the top of the tree is the Cone Nebula. At the bottom left is a complicated web of gas often called the Fox Fur Nebula.

This image is, of course, just the one I took three weeks ago dressed up in Christmas colors (actually, the image is a monochrome image taken through a narrow slice of the deep red part of the spectrum). Enjoy the season!

December 10, 2010

IC417 (12-1-2010)

IC 417 is a wonderfully complex hydrogen nebula in the constellation Auriga. So many different things to see here!

This image is just 9x8' with the Atik 16 through the Orion 120mm achromat with WO 0.8x II ff/fr (thus at f/4). Processing was done in Nebulosity, Maxim, and PS CS3.

M97 (11-30 and 12-1-2010)

This planetary nebula in Ursa Major is, like all planetary nebulae, an expanding cloud of gas and dust sloughed off a dying star. The star, which you can see in the center of the nebula, is a white dwarf, the super-hot core of what is left of the dying star. The filters used to take this shot cover three wavelengths common to planetary nebulae: Ha, NII, and OIII. In fact, the Ha filter's bandwidth is 12nm wide, and it takes in the NII line. The consequence is that I can't tell whether the red glow in this image comes from hydrogen or nitrogen. The OIII line is far more prominent, however. Ionized oxygen seems to dominate this planetary. M97's distance (and thus its size) are the subject of wildly varying reports, so I have no idea how far away this thing is.

This image is 24x8' with the Astronomik Ha filter and 23x8' with the Astronomik OIII filter. The camera was the Atik 16, and the image was shot through the Orion 120mm achromat with the WO 0.8x II ff/fr, at f/4. Color was done with Cannistra's bi-color technique.

Here is the Ha [+ NII]:
Here is the OIII:

December 3, 2010

The Squall Line in the Rosette (12-1-2010)

The Rosette Nebula is about 5,000 light years away in the constellation Monoceros. (In wider images, it really does look like a flower. See RoryG's recent image.) A long chain of nebulosity appears in very deep images to connect it to the Cone Nebula complex. (See Wolfgang Promper's image here.) This part of the Rosette Nebula is where clouds of dust and gas in front of all the lit-up ionized hydrogen clouds are silhouetted in the light. The clouds are slowly disintegrating in the ultraviolet radiation from the bright stars in the lower center of the image, the stars of cluster NGC 2244. Yet still tiny pockets of the dark stuff remain randomly ahead of the front, globs dust and gas perhaps shrinking under gravity and resisting the radiation scattering the rest of the matter around them.

This image is 17x8' with the Atik 16 through the Orion 120mm f/5 achromat, the WO 0.8x II ff/fr (so imaging at f/4), and an Astronomik Ha filter.

December 1, 2010

The Cone Nebula & NGC 2264 (11-30-2010)

This beautiful area of the sky has no bright stars. Without optical aid, it looks empty from the burbs were I live. But with the light pollution extracted, and with a sensitive camera and a large lens to gather and focus the light, great things can be seen.

On the left of this image is the Cone Nebula, a dark cloud that is slowly disintegrating in the radiation generated by the bright stars to the right of it. The cluster of stars, known as NGC 2264, and the cloud of hydrogen gas shown here, can be found about 2,600 light years away. These objects, like the California Nebula, lie in the same arm of the galaxy that we inhabit.

This image is 18x8' with the Atik 16 through the Orion 120mm f/5 achromat and WO 0.8x II ff/fr (so the image was taken at f/4) and an Astronomk 12nm Ha filter.

This image was published in the April 2011 issue of Ciel Extrême, page 15.  Thanks to the editor, Marc Cesarini.  It's a great privilege.

Central California: NGC 1499 (11-30-2010)

This is the central and most interesting (to me) region of NGC 1499, sometimes called the California Nebula. In moderately deep images, the nebula takes on a shape something like that of the state of California. In deeper images, the shape is more like a scimitar (see, e.g., this image from Don Taylor). This much narrower view only shows the Bay Area, the darker cloud in the middle of the image. The bright nebulosity running from upper left to lower center is the coastline. In this relatively deep image, the nebulosity runs into the ocean and out past the edge of the image. The California Nebula is about 1,500 light years away, and is found in the constellation Perseus. It inhabits the same arm of the galaxy that we do.

This image is 13x8' with the Atik 16 through the Orion 120mm f/5 achromat and WO 0.8x II ff/fr and an Astronomik 12nm Ha filter.

November 29, 2010

NGC 3198 (11-26-2010)

This galaxy in southern Ursa Major is about 35,000,000 light years away. Normally, I present galaxies in white against a black background. In this case, the waning moon was still 66% full and only about 20 degrees away from this galaxy. That's not the best condition for shooting a galaxy. But the camera was running. I could turn it off and go to sleep, or let it run and go to sleep. I decided to let it run on this object. The resulting image is noisy and does not show well at all in white on black. It's much better this way, black on white, and more of the galaxy is visible.

This is 38x4' with the Atik 16 through the AT8RC and the IDAS-LPS-P2 from the backyard in The Woodlands, TX.

November 27, 2010

NGC 2392, the Eskimo Nebula (11-26-2010)

This little fellow sits up in the sky, smiling and winking at us! It's cold in space, so he wears a parka!

This planetary nebula is famous for looking like an Eskimo. It's actually a bright nebula roughly 2870 light years away in the constellation Gemini. The Hubble has taken an image of this cloud, but beware: the Hubble's excellent resolution erases all resemblance to an Eskimo. Instead, the Hubble's is the Mummy Nebula.

This image was 25x4' taken with the Atik 16 through the AT8RC and an IDAS-LPS-P2.

IC 410 Tadpoles & Part of NGC 1893

These tadpole-like structures are part of a cloud of hydrogen and other gases and dust in the constellation Auriga. A cluster of stars, dubbed NGC 1893, has formed from the cloud. Those stars can be found throughout the image but are centered in the upper right, where the brightest of them are found. The brightest stars of NGC 1893 radiate energy which is pushing the cloud of gas and dust away. But some of the cloud is thicker and may hide stars in formation whose gravity counteracts the radiation from the bright stars. Where this occurs, the gas and dust remains, and a shock front forms where the radiation meets the stubborn part of the nebula. Behind the edges of the shock front and trailing away, is the gas and dust pushed around and away, like a tail, from the stubborn gas and dust remaining in the head, giving the tadpole-like appearance.

This image is 32x4' with the Atik 16 through the AT8RC and an IDAS LPS-P2 filter. The 67% moon rose during the final sub-exposures. The stars here are slightly out of round. I believe it is the way the camera is attached to the focuser. Honestly, I wish focusers had T-threads. It'd be so much easier.

November 21, 2010

NGC 7662, the Blue Snowball Nebula (11-16-2010)

I see varying reports of this planetary nebula's distance from us: 1800, 3900, and 5000 light years. I don't know how far it is, but it is fairly bright. This image was taken with the AT8RC at f/8 with the SXVF-H9C. It is 40x60".

November 20, 2010

NGC 457 (11-17-2010)

NGC 457 is an open cluster of stars about 8,000 light years away in the constellation Cassiopeia. This image is 33x180" with the AT8RC at f/8, SXVF-H9C.

November 9, 2010

NGC 2419 (11-5&6-2010)

NGC 2419 is a very distant globular cluster. It lies 300,000 light years away. If our galaxy were a frisbee, NGC 2419 would be at least two frisbee lengths beyond its edge! It was once thought to be free-floating in space, unconnected to any galaxy, but we now believe it is in orbit around our own Milky Way. NGC 2419 is the 5th most distant globular cluster from the sun. Source. The brightest stars in NGC 2419 are 17th magnitude.

This image is 28x5' with the AT8RC and the SXVF-H9C, from my backyard in The Woodlands. Actually, my last image of this was so fuzzy and faint that I have wanted to take another try. The prior image is posted here.

Here is a smaller version. Shrinking it a bit hides some of the noise and helps the star shapes in the cluster look more round:

NGC 1275 (11-5&6-10)

This not-so-deep image of this fascinating object (the brightest galaxy, in the lower part and just left of center) leaves much for the imagination. Here is a brighter rendition, through a much larger scope with much longer exposure; in fact, the best rendition I know of by an amateur. The galaxy is thought to harbor an active black hole and is combining with a smaller galaxy, giving NGC 1275 its unusual shape and other characteristics.

The galaxy cluster is called Abell 426, also called the Perseus Cluster. This is just the heart of it. What you are seeing is approximately 237 (give or take about 30) million light years away.

This image is just 2.25 hours of 5' exposures with the AT8RC and the SXVF-H9C.

November 3, 2010

M37 (10-29-2010)

This open cluster of stars is 4,150+-550 light years away in the constellation Auriga. It thus lies in the plane of our Milky Way Galaxy roughly looking out away from the galaxy's center. This image is 17x300" with the AT8RC (w/0.8x ff/fr, for a focal length of about 1300mm) and the SXVF-H9C. Here is a smaller version:

November 2, 2010

NGC 891 (10-29-2010)

This galaxy is 30 million light years away in the constellation Andromeda. This is image is 36x300" with the SXVF-H9C through the AT8RC (w/0.8x ff/fr, at about 1300mm). Captured in Neb2 and processed in Neb2, Maxim, & PS3.

November 1, 2010

NGC281 (10-29-2010): A Few Short Subs

This is just 4x300" with the AT8RC, 0.8x ff/fr, and the SXVF-H9C. The Pacman Nebula was high in the sky, and I wanted to test collimation, focus, exposure time, and tracking on something familiar. Generous noise reduction has been applied to the combined stack, and the image size has been reduced, also to decrease noise. The focal length is around 1300mm. There are still problems, as in the bottom left corner, but I am getting close. I think I know what I'm doing with collimation now, at least.

October 24, 2010

NGC2174 (10-2-2010)

NGC 2174 is the nebular complex. (More details later.)

IC 348 (10-2-2010)

IC 348 is the star cluster at the center of this image. It is being formed from a large cloud of gas, mostly hydrogen, about 1040 light years away. The space to the right of the cluster seems more barren of stars because the cloud of gas and dust, from which the stars are forming, blocks the light of the forming stars and the light of the stars behind the cloud. This image is 20x480" through an Astronomik Ha filter. It therefore shows only the hydrogen emission line. Full spectrum images of this area also show light reflecting from the hydrogen clouds and nearby dust and gas.

October 19, 2010

Cederblad 214 (9&10-2010)

After the Pelican Nebula set behind the trees, this nebula in Cepheus was nicely positioned for a three hour set of sub-frames. During the long stretch of clear nights in September and early October, I could end the Pelican set around 1 am, then slew over to Ced 214 and begin another three hour set. This nebula is mapped similarly to the Pelican, in the Hubble Palette. Exposure times here were Ha=27x8'; OIII=30x8'; SII=38x8'. Processing was done in Neb2, Maxim DL 5, Registar, and PS CS3. The Ha is below:

October 14, 2010

Pelican Redux

This is the same data as earlier this month, but the color for this image was done in PS CS3. This method gives me more control over the color balance and intensity and makes it easier to make other changes later. I processed this to be closer to the actual strength of the data that I obtained. I believe this resulted in the colors being less grainy and the contrast more vivid. Thanks for looking.

October 12, 2010

The Great Nebula in Orion (9&10-2010)

This nebula is one of the most famous in the sky. It is visible without optical aid in the belt of Orion's sword. It is basically a huge cloud of gas and dust, mostly hydrogen, that is coalescing to form stars. The stars just lower left of center are newly formed and are sending out the radiation that makes the clouds of gas glow. The four bright stars are called the Trapezium. Actually, there is a knot of stars there. This image was shot at a focal length of 500mm, not enough resolution to allow the other stars to be seen clearly. This nebula is a stunning sight in a telescope. These colors are false, but in a large scope the entire nebula takes on a greenish glow that contrasts with the stars and with the dark sky behind it.

This image is about 2 hours per narrowband channel: Ha (mapped to green), OIII (blue), and SII (red). I also took a string of 30-second Ha exposures designed to show the four stars at the core of the nebula without totally blowing it out. Processing was done in Neb2, Maxim DL, Registar, and PS CS3. This is another image gathered with the 120mm achromat and the Atik 16. It's turned out to be a nice combination.

October 7, 2010

More Soap Bubble (10-6-10)

Here is what I know how to do with the Soap Bubble Nebula. I gathered more data this week. This is 92x8' (50x8' of H-alpha and 42x8' of OIII). It was processed in Neb2, Maxim, Registar, and PS CS3. The two sets were combined using Steve Cannistra's Bi-Color Narrowband technique. I'd be happy for any suggestions as to how to improve the image.

The Soap Bubble Nebula, called by scientists PN G75.5+1.7, actually looks alot like Abell 39, another planetary nebula, discovered in the 1960s. My image of Abell 39 is here. I would like to revisit Abell 39 someday.

October 2, 2010

Soap Bubble Nebula (9-30-2010)

Dave Jurasevich, an amateur astronomer, discovered this planetary nebula in 2008 while trying to image something else (see here). Keith Quattrocchi and and Melvin Helm found it independently a few days later (see here). It is very faint, actually, but here it is. This image is 20x8' in H-alpha and 11x8' in OIII, taken with the Atik 16, processed in Neb 2, Maxim DL 5, and PS CS3, mostly just stretched until it almost breaks. This image is black and white, inverted, and equalized in PS.

Can you see the bubble in these other iterations? The first is black and white, and the second is similar to natural color, with Ha as red.

Pelican in Narrowband (9-2010) - Prelim

This is my first full narrowband image with the Orion 120mm achromat at f/4. This is what I think is the most interesting part of the Pelican Nebula in the constellation Cygnus. The colors are not what the eye would see. Most of the glowing, ionized gas here emits light that would appear red to our eyes. But here, so that we can more easily see what is going on, glowing hydrogen is colored green, glowing oxygen blue, and glowing sulphur red. Yellow is where red and green glow together. The energetic stars embedded in the nebula energize the gas and set it aglow. North is to the right in this image.

The most interesting part of the nebula is the dark finger that reaches up from the ionization front. At the top of this finger is a relatively small, dense cloud of gas and dust slowing being worn away by radiation from the stars lighting the nebula. Hidden in the cloud, a star is being born. We cannot see the star inside the cloud, but the newly-forming star is shooting jets out to the north and south. The jets are visible in this image. The radiation that makes the gas glow is pushing the jets down to one side. This interesting object is called by scientists Herbig-Haro 555.

This image is the product of just over 10 hours of 7 minute exposures added together. H-alpha (hydrogen) was 45x7', OIII (oxygen) 22x7', and SII (sulphur) 20x7'. The image was taken with the Atik 16 from my backyard over three nights in late September, 2010.

September 30, 2010

The Flame Nebula (9-27&28-2010) - Prelim

This image is 22x7' in Ha and 19x7' in SII, using Astronomik filters, taken with the Atik 16 through the Orion 120mm refractor at f/4 (with the WO 0.8x II fr/fr). Ha was used as luminance and mapped to red and green; SII was mapped to blue. Processing was done in Neb 2, Maxim DL 5, and PS CS3.

September 28, 2010

First Light with the Orion 120mm f/5 w/ 0.8 Reducer Achromat Astrograph: A Pelican Preliminary

A few weeks ago I saw advertised on Cloudy Nights an adapter that would allow me to attach my Feathertouch focuser to an Orion 120mm f/5 achromatic refractor. I didn't own one at the time, but it occurred to me that perhaps the WO 0.8x II reducer/flattener that I do own would work with this scope, which has a focal length of 600mm. An f/5 x 0.8 would yield an f/4, and a 120mm f/4 refractor sounds like a honey of an astrograph. It could only be used for narrowband imaging, but that's all I can do when the moon is full, and it's fascinating work, anyway. I made an offer to buy the adapter, then went looking for a used scope. I found one a few days later. With adapter and scope put together, I waited for a clear night. Here we are.

This image is 18x420" through the Orion 120mm f/4 achromat astrograph, with WO 0.8x II reducer/flattener and an Astronomik 12nm Ha filter. The camera was the Atik 16. The image needs a bit more time. I hope to get that tonight, but this is a promising result for a used scope that, with adapter, cost less than $300.

September 16, 2010

Albireo (9-15-10)

On some nights of imaging, nothing works. I took the AT8RC out to see what I could do with it. I couldn't do much. I did not have the optics aligned correctly, and I was getting flexure between the guide camera and imager. So it turned out none of my stars were round. I was tired, too, but I wanted to try. Clear nights don't come around often. This was the only shot all night that worked, and this only halfway. Only by shrinking it down could I hide the slightly out of shape stars. I did get one frame of M45, too, but just a single sub---not enough to post.

Albireo is the beak of Cygnus, the Swan. It is a beautiful pair of stars, one that many look for each time they go out in the summer to observe. Albireo is about 380 light years away. The two components may or may not revolve around each other. The brighter star is itself a double star, so if the two components seen here revolve around each other, then Albireo is a triple star system.

September 7, 2010

NGC 6960: A Veil Unveiled (9-4-10)

This was my primary target at the SHSU Observatory site. This image is 29 x 360" or 300" (the first five or so subs were only 5 minutes each), processed in Neb 2, Maxim, and PS3. Obviously, having a dark sky is a real plus on such a faint object. I was delighted to see the scope and camera perform so well. This was taken through the Orion 6" I-Newt with Baader MPCC and IDAS LPS2 filter, guided with a DSI Pro through a Borg 50mm guidescope on the Takahashi NJP.

Rory Glasgow saved my night. I left my laser collimator at home on the desk. After fiddling around with the primary mirror for a bit, I realized the strange star shapes I was seeing were a result of my secondary aiming somewhere other than at the center of the primary. Lucky for me, Rory had an accurate laser collimator. Ten minutes later, my stars were perfect circles, I was focused again and ready to go, still with 2.5 hours of the Veil near the zenith. Thanks, Rory.

Jim Wood also saved my night. I have been using T-shirt flats for some time now, but I couldn't stay at the observatory site until morning. Lucky for me, Jim brought a Flip-Flat that fit over the end of the 6" I-Newt. We were parked next to each other, and Jim loaned me the unit for a few minutes. I owe the flatness of the image to Jim. Thanks, Jim.

Here is a monochrome version:

M33 & A Night in the Dark (9-4-10)

This image of M33 is just 5 x 420" with the SXVF-H9C through the Orion 6" I-Newt, processed in Neb 2, Maxim, and PS3. It was late, and I wanted just one more target. Really, the galaxy needs another couple of hours of data, but this process is not just about pretty pictures. Here is an observation of the galaxy, reported in living color.

August 30, 2010

A Moon-lit Veil (August 2010)

This image was taken with the moon 90% lit and about 50 degrees away from this nebula, but I was going in for some sleep and figured it wouldn't hurt to try. This is 46x4' with the SXVF-H9C through the 6" Orion I-Newt. The Veil is dim. You may have to turn off the lights to see it in this image, but there it is.

August 29, 2010

NGC 6791 (August 2010)

This image was taken with the moon 90% full, but it was the first clear night for me in about six weeks. It was time for a photon fix!

NGC 6791 is a curious open cluster of stars in the constellation Lyra. It contains as many as 10,000 stars. (Obviously, only the brightest are visible in this image, taken with the moon almost full from a light-polluted suburb.) This cluster is also one of the oldest open clusters known, estimated at about 8 billion years. What is doubly curious about this cluster is that another group of stars in the cluster appears to be about 6 billion years old. That's odd because most stars in open clusters form at the same time, so they should all be roughly the same age. The 6 billion year old stars are all white dwarfs, and none of them are bright enough to show up in this photo. You are seeing only the 8 billion-year-old cluster stars here. Source. NGC 6791 lies about 13,000 light years away.

This image is 30x4' with the SXVF-H9C through the 6" Orion I-Newt.

July 17, 2010

M19 (7-13-10)

There is little remarkable about this image, but I had never seen M19 before and so took this single frame of about 3 minutes length. M19 is about 28,000 light years distant in the constellation Ophiuchus. This was taken with the AT8RC at f/8.

July 15, 2010

NGC 6528 & NGC 6522 - The Sibling Globs

These two globular clusters appear together in the sky. In fact, they are together! The one on the right lies about 25,400 light years away, and the one on the left 25,700 lights years. They are near neighbors! Both are roughly 2,000 light years from the center of the galaxy. Source. What intrigues me is that they can be seen in a single view through the telescope. They light just north of the star which tips the spout of the teapot that is Sagittarius. It's as if they were two balls of steam puffed out of the teapot itself! Both are reddened and dimmed because they lie in the plane of the galaxy behind a great deal of dust. And, because they lie in the plane of the galaxy, they appear surrounded by stars.

This image is actually two panels combined, taken with the AT8RC through the SXVF-H9C at the scope's native f/8. Processing was done in Neb2, Maxim, and PS CS3 and Photoshop Elements 7 with a Carboni action for star color. Exposure time was a mere 5x3' for each panel.

Another M16 (7-13-10)

This M16 is 27x4' with the SXVF-H9C through the AT8RC at its native f/8. I still have funny star shapes, just a little. I think I have narrowed it down to slight miscollimation. No need to throw out the data, though. What a fascinating object! No filters on this one, either.

I'd be interested to know which of the two versions is preferred. The first image above is truer to actual colors, I believe. The second maximizes the Ha glow.