NGC 1999, the Keyhole Nebula (Dec. 12, 2012)

This is NGC 1999, the Keyhole Nebula.  It is a reflection nebula lit by the star on the right edge of the lower part of the keyhole.  The nebula is so bright there that it is difficult to see the star separately from the nebula.

The interesting thing about the Keyhole Nebula is that it is actually a hole.  Many dark spots seen against a brighter nebular background are cold clouds of gas and dust.  Not so the Keyhole, apparently.  The keyhole feature appears actually to be a hole.  Deep images with a variety of infrared scopes (reported here) show that in the keyhold feature there lurks ... nothing.  What blasted a hole through this patch of otherwise brightly lit cloud?  That is a mystery, but the area is full of young stars just beginning stellar life.  Perhaps one of them blasted a tunnel right through.

Mine is not a deep image.  Surrounding the blue reflection nebula is a lot more gas and dust that is not lit up so brightly with reflected light.  Some more interesting objects my image only begins to show are also brighter in other pictures of the region.  You can see some of them in Adam Block's image, here, taken with a much larger scope from the top of a very dark mountain.  In my image you can see just a hint of these other things in the reddish background and in the red glowing objects just to the right of the Keyhole Nebula.

Telescope: Orion 254mm f/4.7 Newtonian and RCC I
Camera and Exposure: SXVF-H9 (R: 9x240"; B: 10x240" (synthetic green)), T-shirt flats
Filter: Astronomik RB, IDAS-LPS2
Guiding: SX Lodestar and SX OAG
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Registar, Photoshop CS3
Location: The Woodlands, TX

Rosette Nebula and NGC 2244 (Dec. 17, 2012)

Link to full resolution here.

The Rosette is a grand sight.  I have seen it in binoculars from the mountains near Reno, NV, but the nebula's relatively low surface brightness makes it a challenge visually from the city.  This is just the central area.  It's fascinating for its dark clumps of dust and gas in the upper left, the bubble carved out of the middle by the hot stars of the cluster NGC 2244, and the loops and filaments throughout.

This is second light with the AT111EDT.  This is just H-alpha.  I hope to go back for OIII and perhaps SII in the coming months.

Telescope: Astro-Tech AT111EDT and William Optics P-FLAT4 (eff. at f/5.6)
Camera and Exposure: SXVF-H9C (10x900"), Alnitak Flat-man flats
Filter: Astronomik 12nm Ha [+NII]
Guiding: SX Lodestar and SX OAG
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Photoshop CS3
Location: The Woodlands, TX

M1 (Dec. 12, 2012)

Link to full resolution image here.

In 1054 A.D. , Chinese astronomers noted a new star in the sky.  It shone so brightly that folks could see it in the daytime.  But the star was temporary.  In fact, it was not a new star at all but an old star that exploded.  This nebula is the result of that explosion.  M1 is a supernova remnant.  It is one of the coolest deep sky objects in the heavens.

Why so cool?  Well, first, this is one of the few deep sky objects whose origin was observed by human beings, and it's been growing ever since.  Most objects in the sky change very slowly by our time scale, but not this one.  In fact, some amateur astronomers have observed changes in M1 in their own images over time.

Second, M1 is not just a supernova remnant.  It is the home of what is left of the star that exploded.  The core of the supernova did not have enough mass to become a black hole, so it stopped just short of that and became a neutron star.  Within it, gravity's power has overcome the forces that create space within atoms, crushing the elements away.  What is left is a ball of neutrons only 15-18 miles wide that contains more mass than the Sun!  Pretty heavy stuff!

But there is more.  The neutron star and its interactions with its immediate environment produce more than just visible light.  Radio waves, x-rays, and gamma rays all stream out of the center of M1.  See NASA's combined optical and x-ray image of the center of M1 here.  The neutron star's intense radiation causes this to happen.

Even more remarkably, the neutron star is spinning very quickly.  It's strong electromagnetic field concentrates the radio waves into pulses that tick like a clock in space.  When astronomers first heard it, its regularity suggested that astronomers were receiving a signal from aliens.  But theorists later determined how a neutron star could produce such pulses.  We call such a spinning neutron star a pulsar.

The pulsar itself is visible in this image.  At the center of the nebula are two stars, easily visible next to each other.  The pulsar is the dimmer of the two, on the right.  We may not have a picture of a black hole yet, but we have images of the next closest thing.  How cool is that?

This image is a combination of (1) a stack of frames taken through an H-alpha filter with (2) a short color image I took a year ago through the same telescope.  I have simply slapped the color over the H-alpha image.  Here is the H-alpha alone:

Here is the capture data for the H-alpha image:
Telescope: Orion 254mm f/4.7 Newtonian and RCC I
Camera and Exposure: SXVF-H9 (H-alpha: 10x900"), T-shirt flats
Filter: Astronomik 12nm Ha
Guiding: SX Lodestar and SX OAG
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Registar, Photoshop CS3
Location: The Woodlands, TX

The color data is described here.

M33 (Nov. 16 & 17, 2012)

Link to full resolution image.

M33 is about 2.88 million light years away (give or take a hundred thousand or so).  That's practically in our backyard.  M33 is, with M31, our next-door neighbor in the universe.  M33's nearness is why it appears so large in this scene.  As galaxies go, M33 is not that big, or that bright.  Compare it with M31, which I shot a couple of months ago with the exact same equipment, and you can see how much larger and brighter M31 is by comparison.

Anyway, M33 is beautiful.  I've always wanted this kind of image of it.  I'm sure this won't be the last time I shoot it.  This image has been shrunk to 80% of original size to hide latent noise; this image could use another six hours or so (and from a darker site).

Telescope: SV80ED (and William Optics 0.8x II fr/ff (eff. at f/5.6))
Camera and Exposure: SXVF-H9C (49x480"), Alnitak Flat-man flats
Filter: Hutech IDAS-LPS2
Guiding: Meade DSI Pro and Hutech 50mm
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Photoshop CS3
Location: The Woodlands, TX

NGC 1977, the Running Bigfoot Nebula (Nov. 16 & 17, 2012)

Link to full resolution image.

This nebula is part of a great complex of gas and dust in the constellation Orion.  The most prominent part of the complex is M42 and M43.  M43 and part of M42 can be seen at the bottom of this image.

The Running Bigfoot Nebula glows mostly for a different reason than M42 and M43, however.  While M42 and M43 radiate the light of ionized gas, the Running Bigfoot reflects the light of the bright blue stars in and around it.  If you look closely at the Bigfoot figure, you see in his trailing arm the reddish glow of ionized gas, probably hydrogen and nitrogen.  But the blue light of the nebula is reflected.  Further away from the bright stars, where the light is too dim to be reflected in blue, it is reflected in gray and then brown.

The Running Bigfoot Nebula is called by most folks the Running Man Nebula, but look at the size of those arms!  And he's got no neck.  He's like no man I ever saw.  His trailing leg is behind a bush, I think.

Telescope: SV80ED (and William Optics 0.8x II fr/ff (eff. at f/5.6))
Camera and Exposure: SXVF-H9C (50x480"), Alnitak Flat-man flats
Filter: Hutech IDAS-LPS2
Guiding: Meade DSI Pro and Hutech 50mm
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Photoshop CS3
Location: The Woodlands, TX

M46, NGC 2438, Minkowski 1-18 (Nov. 16 & 17, 2012)

 Link to full resolution image.

This image shows the open cluster M46 in the constellation Puppis.  The non-stellar ring of material that seems to be within the cluster is planetary nebula NGC 2438.  The nebula is actually in front of the cluster, astronomers believe, and just a chance alignment makes the cluster and the nebula appear together in the sky.

A wide field view is great for an apparently large open cluster like M46.  But to see the planetary nebula in detail, an imager must use a much longer focal length.  How about this image, taken through narrowband filters with the 0.82 meter IAC80 telescope?  The IAC80's 9-meter focal length reveals a host of details that my telescope's 0.5-meter focal length could never show.

As I was processing this image, I found another planetary nebula in it to the left of M46 and NGC 2438.  This nebula is cataloged as Minkowski 1-18, PK 231+04.1, and PN G231.4+04.3.  It is to the left (north) and down (east) just a bit from NGC 2438 and is near the edge of the frame.  It appears as a dim, dark red, circular patch just a little larger than the footprint of the brighter stars near it.  You may have to look at the full resolution image to see it.  I was happy to see it as I did not know it was there before taking this image.

Telescope: SV80ED (and William Optics 0.8x II fr/ff (eff. at f/5.6))
Camera and Exposure: SXVF-H9C (46x480"), Alnitak Flat-man flats
Filter: Hutech IDAS-LPS2
Guiding: Meade DSI Pro and Hutech 50mm
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Photoshop CS3
Location: The Woodlands, TX

M42 Trapezium (Sept. 22, 2012)

The lovely little cluster called the Trapezium lies at the heart of M42, the Great Nebula in Orion, and is named after the shape made by its brightest stars.  M42 and the Trapezium are one of the grandest sights in the sky and are subjects for serious study.

The cluster's stars are close together, literally as well as apparently.  They appear so close that they were once thought to be one star, Theta Orionis.  As astronomers over time split the star into more and more components, they named the components with letters.  The brightest star in the cluster is Theta Orionis C.  It is very bright, very hot, and generates most of the ultraviolet radiation that makes the gas around it glow.  In the image, the star at the top of the Trapezium is D.  The two brighter other stars that make up the trapezoid, going from left to right, are A and B.  Here is a close crop of the cluster:

As more components were discovered, more letters were used.  The semi-bright star between A and B (and just to the right of A) is E.  The star just above C is F (which looks elongated; actually there are two stars there).  The star just below D is G, and directly below G is I.  Moving to the lower left of I is H, which is just below C and to the left of A.  Next to H, to H's immediate left, is another star, and I have no idea what it's name is.  Nor do I know the names of the other, nearby stars.  Actually, I was surprised to see so many here.  But this is not anywhere close to all the stars in the cluster.  Many of them shine in wavelengths other than those allowed by the two filters that I used to take this image.  I should explain.

One of the cool things about this nebula is that stars in it are still forming.  There is still a lot of dust obscuring stars that have formed, and the stars do not all glow with the same intensity at all wavelengths.  When we take pictures, we often use different filters that cut out all but a few wavelengths.  This allows us to focus only on the gases that light up the nebula, to the exclusion of almost all other light (including streetlights in front of my house).  For example, this image records light with a wavelength of 656.28 nm.  At that wavelength we find light emitted by ionized hydrogen.  Very near it we also find the light of ionized nitrogen, and my filter (called an h-alpha filter because it focuses on the hydrogen emission) just happens to pass light from a band 12 nm wide.  It is wide enough that it also picks up the nitrogen signal.  This image also records light taken through another filter that allows the wavelengths of 495.9 nm and 500.9 nm, and this light is emitted by ionized oxygen.  This filter is often called an OIII filter.  The h-alpha line is in the red part of the spectrum, and the OIII lines are green, but I've mapped OIII to blue here, also, because blue and red make a better picture.  So here you see the stars as they shine at those wavelengths.

But look at this next image.  I also took an image through an SII filter, which allows in light of ionized sulfur, at wavelengths of 671.6 and 673.1 nm.  The image is quite different:

More stars appear, and they are brighter.  Why is that so?  It may be because these stars radiate more light from ionized sulfur than from hydrogen, nitrogen, or oxygen.  I suspect that is the case.  Notice that stars G, H, and I are dimmer in this SII image, and that F is not elongated.  

The best way to see this cluster, though, is at infrared wavelengths.  Not until wavelengths of 750 nm do we reach the infrared.  Infrared light cuts through the dust, so an infrared image shows hundreds more stars in the area.  An example from the Hubble Space Telescope is here.  How cool is that?  On the other hand, when the Hubble records in h-alpha, nitrogen, and OIII, as I did, it picks up the same stars I do in the first image above (and a few more with Hubble's better resolution and bigger aperture, of course, but nothing like the infrared), as here.

Anyway, I took these images of the Trapezium from my backyard, in about an hour's time.  The stars are so bright that only short exposures would keep the stars small enough to remain separate.

Telescope: Orion 254mm f/4.7 Newtonian and Astro-Tech Coma Corrector (eff. at f/5.17)
Camera and Exposure: SXVF-H9 (H-alpha: 11x30"; OIII: 15x30"; SII: 15x30"), T-shirt flats
Filter: Astronomik 12nm Ha, OIII, and SII
Guiding: SX Lodestar and SX OAG
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Registar, Photoshop CS3
Location: The Woodlands, TX