Primordial Light: Deep Sky 6

Primordial Light: DEEP SKY Page 6

The Horsehead and Flame Nebulae in Red Light

horsehead red

The Alnitak region of the constellation Orion, photographed on November 8, 2009. Alnitak is the brightest star in the photo. Notice the little bump at the 9:00 position on Alnitak. That is one of Alnitak’s much dimmer companion stars. There is a captioned color photo of this region here, and a photo in the narrow Hα spectrum here.

NGC 2359 “Thor’s Helmet” in Canis Major

My God, it’s full of stars—Dave Bowman.

December 16, 2009: the close-up photos of NGC 2359 that are often seen do a beautiful job of revealing the delicate whorls and filaments of the nebula, but they frequently fail to portray the incredibly rich starfield in which the nebula lies, so I chose to take the wide view with a Takahashi FSQ-106ED Astrograph. The field here is about 2.4 X 1.6 degrees. The camera was a Canon 40D, as my SBIG STL-11000M is away being repaired. Captured with Canon’s camera-control software. Processed in Nebulosity, Pixinsight, and Photoshop CS3 Extended. Mount control was done with TheSkyX Serious Astronomer Edition and guiding of the 12 five-minute exposures was via a Starfish guide camera. There is a larger version here. The larger version will open in a new window; re-size your browser window as needed to enlarge it up to its maximum of 2048 X 1401 pixels. All-Mac image.

Simeis 147 Revisited, January 9, 2010

The long-focal-length telescope that I used to photograph Simeis 147 in November, 2009, presented a very narrow view, so I decided to re-do the image using a wide-field astrograph. As this image shows, even my wide-field telescope was not capable of capturing all of this supernova remnant. That will require yet another visit with a focal reducer. This object is nearly eight times the diameter of the full moon. Click the image for a larger version.

Tech stuff: Tak 106 mm refractor/fl 530 mm (f5). Camera: SBIG STL-11000M with 4.5 nm Hα filter centered at 656.3 nm. FOV: 3° 53' x 2° 35'. Eight 15-minute exposures. All-Mac image: TheSkyX SAE, Equinox 6, Nebulosity, PHD Guider, Photoshop CS3.

M46 and M47, January 18, 2010

More for your money. Pass your cursor over the image to see four star clusters identified along with one planetary nebula (NGC 2438). The brightest star in the image is magnitude 5. The faintest star in the full-size image is less than magnitude 21. Here a magnitude 20 star is identified.

RGB image from an SBIG STL-11000M on a Tak FSQ-106. All-Mac image: TheSkyX SAE, Equinox 6, Nebulosity, PHD Guider, Photoshop CS3, Pixinsight.

The Spiral Galaxy M100 in H-Alpha 22-23 March, 2010

Click here for the full-frame of the image. I binned the CCD 2X (combined pixels) for increased sensitivity. This is a stack of five 15-minute exposures made on the night of 22-23 March, 2010. I made six exposures, but an airplane flew through one of them, and it clouded over before I could get more exposures. The central spiral galaxy (unlabeled) is M 100. It lies at a distance of about 55 million light years in the constellation Coma Berenices. It is part of the Virgo Cluster of Galaxies. None of the galaxies in this image is visible to the unaided eye. Except for M100, most are difficult targets for visual observers. This is a work in progress; when I get another clear night I will photograph this cluster through green and blue filters. This Hα image, used as the red channel and combined with green and blue frames, should produce a nice color image.

Hα image from an SBIG STL-11000M on a Tak TOA-150. All-Mac image: TheSkyX SAE, Equinox 6, Nebulosity, PHD Guider, Photoshop CS3.

M8, The “Lagoon Nebula” in Sagittarius Photographed in Hα, 3-4 July, 2010

It was a dark and clear night, an event that is increasingly rare around central Maryland. Click here for a larger version of the image. Reproduced here, and in the larger image, is the full frame from the STL-11000M with a 4.5 nm Hα filter centered at 656.3 nm.

M8 lies at a distance of about 4,100 light years (on our doorstep in cosmic terms) in Sagittarius. It is slightly to the north and west of Kaus Borealis, which is the star that marks what I consider to be the knob on the lid of the Teapot asterism in Sagittarius. Look south at around midnight in July and August. You can’t miss the Teapot in a reasonably good sky.

At right is an enlargement of a Bok Globule from the image above—a stellar womb, one might say—in which a star—a protostar—is likely forming. The star is in the dark portion of the globule, while the globule’s tail probably represents dust being pushed out of the globule by radiation pressure from the hot, young star. I hope to photograph this region again after a few million years, by which time the baby star should be out of the womb. There is considerable hedging of words when describing Bok Globules because they are not yet fully understood.

protostar

Hα image from an SBIG STL-11000M on a Tak TOA-150. All-Mac image: TheSkyX SAE, Nebulosity, PHD Guider, Photoshop CS3.

M8, The “Lagoon Nebula” in Sagittarius in HαGB, 3-4 July, 2010


I combined the Hα image with exposures made through blue and green filters to come up with a color image. While color is pretty, and it is the way we are accustomed to seeing the world, the color image can’t match the Hα image for clarity and subtle detail. Note that the wispy hydrogen at the top of the Hα image is missing completely from the HαGB image. This is largely due to the fact that the narrow-band Hα filter rejects much of the light pollution that wide-band red, green, and blue filters admit. This light pollution has the effect of reducing contrast and blurring details. On the other hand, measuring the wavelength (color) of light that an object emits is the only way to tell what it is made of, and that requires making multiple exposures through different colored filters.

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