NGC281 again (Oct 2019)

This is just 5x1800" in H-alpha with the Synta-ONTC 203mm f/4.95 Newtonian and the SXVF-H9.

NGC 281 or IC 1590 (Fall 2015)

This lovely nebula is lit up by, once again, a type O multiple star at its center.  In this case, it is HD 5005, a trapezium system of O-type stars on which nearly every ionization front in the nebula seems to center.  Source.  This source names many cluster members as type B, also.

Especially of interest here is the massive cloud of dust in front of the cluster, just to its right.  HD 5005 is eroding this cloud with strong UV radiation, too, but because the cloud is in front of the cluster, it appears as a dark streak with streamers moving away from the cluster of stars.

This image is 20;16;16 x 1800s of SHO from Deep Sky West's FSQ.  I've imaged this object before, several times, and I am proud of higher resolution images here (Ha only) and here (Ha and OIII).

Think this object is cool?  Check out this Hubble shot of the Nebula's center.

NGC 281 Bi-Color (September 2012)

Full resolution link here.

Here is the Pacman Nebula again, a closer view.  The H-alpha data shown earlier this month falls naturally in the red part of the spectrum.  To this I have added OIII.  Ionized oxygen is green, but it is weaker than the H-alpha.  In this image, I have used H-alpha for red, OIII for blue; I combined this data (20% Ha, 80% OIII) to create a third data set, which I used for green.  This is a slightly false color, but I think it is easy on the eyes and shows the data well.

Telescope: Orion 254mm f/4.7 Newtonian and Astro-Tech Coma Corrector (eff. at f/5.17)
Camera and Exposure: SXVF-H9 (H-alpha: 1x900" + 12x1200"; OIII: 15x1200"), T-shirt flats
Filter: Astronomik 12nm Ha and 12nm OIII
Guiding: SX Lodestar and SX OAG
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Registar, Photoshop CS3
Location: The Woodlands, TX

IC 1590 & NGC 281 (Sept. 6, 2012)

Link to the full resolution image.

I've always wanted to get closer to the cluster at the center of this nebula.  A clear night this week presented an opportunity.  I had some trouble with the 254mm Orion Newtonian early on: a poorly installed dew heater was warping the secondary.  When I realized what the problem was and shut off the dew heater, the field quickly flattened out.  By that time, NGC 281 was just coming over the trees.  This is my first image of the nebula with the big Newt, and the first time I've shot H-alpha through the big scope.  I don't think it will be the last time.  This is also first light since installing a Protostar tubeliner inside the scope.

NGC 281 and the open cluster in the center of the image, IC 1590, are about 9,500 light years away.  The nebula is bright because the stars in it are bright.  The nebula is an emission nebula, which means that the gas of the nebula (hydrogen in this image) is excited by the ultraviolet light of the stars in the cluster.  The cluster and nebula are a package deal.

What I like about this nebula in particular are the clumps of gas and dust in front of it.  The clumps are being worn away by starlight, but several of them stand out against the face of the cloud, including the long river near the cluster and several little globules in the upper right.

It's a grand sight!  I recommend clicking on the full resolution link above, toggling F11, and panning about.

Telescope: Orion 254mm f/4.7 Newtonian and Astro-Tech Coma Corrector (eff. at f/5.17)
Camera and Exposure: SXVF-H9 (1x900" + 12x1200"), T-shirt flats
Filter: Astronomik 12nm Ha
Guiding: SX Lodestar and SX OAG
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Photoshop CS3
Location: The Woodlands, TX

NGC 281, the Pacman Nebula (Oct. 20, 2011)

OK, I've shot this before, but this is first light with a used SXVF-H9 camera I have obtained.  The camera has an electrical problem that sends a noise-creating current into the system, and I've sent it off for repair.  SX makes wonderful cameras, and their customer service has been top notch.  I have every hope the camera will come back in fine working order.  At any rate, this first light gives a hint at what the camera can do.  Darks and bias frames subtracted, and flats applied, and reduced in size by one-third.

Telescope: Orion 120ST f/5 Achromat w/WO ff/fr 0.8 II (so effectively at f/4)
Camera & Exposure: SXVF-H9, 18x10'
Filter: Astronomik 12nm H-alpha
Guiding: Borg 50mm, Meade DSI Pro, PHD
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Photoshop CS3
Location: The Woodlands, TX

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.

The Final Pacman, NGC 281

Here is the final for the moment, but I need to look at it for a few days.

The difference between the two is different processing in Registar. Before I combined the three sets in RGB then split them into channels only to re-combine them in Neb2 as LRGB=(Ha)HaGB. For this image, I turned auto-scaling in Registar off, then registered G and B to Ha, calibrated G and B to Ha, then saved the calibrated images. Then I went back to Neb2, aligned the Ha and calibrated G and B, saving each as separate files. Then I combined in LRGB synthesis using Ha as Lum and R, as before, then stretched and adjusted color and background until the stars began to look right. Finally, I opened in Photoshop Elements 7 for cropping, a little unsharp masking, and the application of Noel Carboni's action "Increase Star Color." I am happy with this image. It matches my data quite well.

Other details about the image can be found here.

Here is a false color version. In this rendition, Ha is blue, blue is red, and green is blue. I like it because the blue-white stars show gold against the background of the nebula. It's a nicer aesthetic effect.