NGC 40, the Bow Tie Nebula

A comparatively shallow view of this nebula looks like a bow tie. See?
But the deeper image shows the central star is actually surrounded by a boxy circle of gas (and dust?). The structure of the nebula is also bipolar, with something happening on the north and south. Just what is unclear. A stretch of gas swings out from the north, and from the south a leg is jutting out. Diffuse gas glows all around what appear to be edges of the circle. Compare my view with Don Goldman's here, taken which much larger equipment.

Here's the riddle: Why does this planetary nebula glow so strongly in an image taken with an Ha filter? A planetary is usually formed when a dying star is dying because it has used up the hydrogen reserves necessary to burn like normal a star. It then swells up like a balloon and starts blowing the outermost layers into space. If the hydrogen left is not prominent in these stars, why does this nebula glow so brightly through an Ha filter, which focuses on the spectral line of ionized hydrogen gas?

There are two answers to this question. The first answer to this question is that my Ha filter lets through not just the important wavelength of ionized hydrogen at 656.3 nm. The filter I have lets through a range of wavelengths 13 nm wide. The 13 nm are roughly centered on the H-alpha line, but the range also includes that of ionized nitrogen at 658.4 nm. So actually everything taken through my Ha filter is Ha + NII.

The second answer is that some planetary nebulae actually contain a great deal of hydrogen. One study that split Ha and NII emissions of planetary nebulae in the Magellanic Clouds (two nearby galaxies) shows that some have more Ha and some have more NII. Some images from the study are here. The upshot is that I do not know which NGC 40 shows more of, Ha or NII. Unless and until I get some even narrower narrowband filters (such as advertised here), I will not be able to discover.

Imaging Scope: Orion 80ED & WO 0.8x II (f/6)
Imager: Atik 16
Exposure: 120" x 31
Filter: Astronomik 13nm Ha + NII
Capture Software: Nebulosity 2
Mount: Takahashi EM-10
Guiding Camera: DSI Pro
Guiding Software: PHD
Guiding Scope: No-name 60mm f/5
Date: Night of 9-26-09
Location: The Woodlands, TX
Processed with Nebulosity 2, Photoshop Elements 7 with Carboni Actions.

First Color Process - M57

The data for this image were obtained from Astrophotography by Rainer Zmaritsch & Alex Gross. It comes from one of their interesting IRIS tutorials. Thanks, guys. Processing was done by yours truly entirely in Nebulosity 1 and Photoshop Elements 7. [Reposted after adding more blue and subtracting a bit of green at the suggestion of Don Taylor of the famed http://www.theatomiccafe.com/. Many thanks. We are all guessing on the color a bit, as we have not calibrated color processing with the sensitivity of the Atik 16HR camera with which the data were gathered. I hope I haven't overdone the blue now.] Other comments? Yes, I have a lot to learn, but I think it's wonderful to see color from a ccd, finally, thirty months after buying my first monochrome camera. Now I look forward to obtaining some filters and a filter wheel.

IC 1318 Re-Process

I've been experimenting with color. This is a re-process with Ha as red and the gradient removed. There may be slight north-south (left-right) elongation in the dimmest stars in the image.

IC 405 Re-Process

On this stretch, the white point was moved left after the mid-tones were brightened, and the dark red default of the Carboni macro was lightened. Is this better?

Venus & Regulus (9-20-09)

Early this morning, through the clouds, Venus appeared half a degree from Regulus. Then the clouds took over.

Venus & Luna (9-16-09)

This was the view from the backyard: a cheery conjunction on a cloudless morning!

NGC6820 & 6823

NGC 6820 is a wonderfully detailed combination of bright and dark nebulae in the constellation Vulpecula, just south and east of Albireo and just west of M27. NGC 6823 is the cluster of stars embedded in the nebula. The cluster formed from the nebula's gas. Radiation from the cluster's hot, young stars now causes the gas to glow in the ionized hydrogen line called H-alpha. Radiation from the cluster is now driving the gas away from the cluster. Where the gas resists, bright walls and dark columns form. Eventually, more stars will form from the gas, and radiation from the stars will continue to push the gas away until the gas is entirely dispersed, leaving only a large cluster of young stars. We are watching stars at birth!

The cluster and nebula sit in the bottom left of this frame because I wanted to make sure the long, dark, elephant-trunk-like column made it prominently into the final photo. I could not see the column on any of my test exposures, though it did appear in some of the 4' subs later on. Anyway, now I see that a 600mm scope does not yield a very large image, and I should have nearly centered on the cluster. But here it is, nonetheless.

My eight-year-old son thinks the larger stars in the center of the cluster look like the wings of a small bee! The dimmer stars in between look like the body, with a stinger on the end. Can you see it? It's the Bee Cluster!

Imaging Scope: Orion 80ED & WO 0.8x II (f/6)
Imager: Atik 16
Exposure: 40x4', or 160'
Filter: Astronomik 13nm Ha
Capture Software: Nebulosity 1
Mount: Takahashi EM-10
Guiding Camera: DSI Pro
Guiding Software: PHD
Guiding Scope: No-name 60mm f/5
Date: Night of 9-6-09
Location: The Woodlands, TX
Processed with Nebulosity 1, Photoshop Elements 7

Flaming Star Nebula, IC 405 & AE Aurigae

This wispy cloud is some of the ionized hydrogen in the Flaming Star Nebula, IC 405, in Auriga. The brightest star in the image is AE Aurigae. That star's energetic output has excited the hydrogen gas around it, causing the hydrogen atoms to lose their electrons. When the hydrogen atoms gain their electrons back, they glow red at a certain wavelength, captured here. The star also shines in blue light, which is reflected in the surrounding nebula, as shown here, for instance. The moon was waning but 95% full when this image was taken.

AE Aurigae is itself a very unusual star. It is a double star, but it is also moving very quickly through space. Astronomers have traced its motion backwards to find that it was ejected from in or near the Orion Trapezium Cluster in the far distant past.

Imaging Scope: Orion 80ED
Imager: Atik 16
Exposure: 37x4', or 148'
Filter: Astronomik 13nm Ha
Capture Software: Nebulosity 1
Mount: Takahashi EM-10
Guiding Camera: DSI Pro
Guiding Software: PHD
Guiding Scope: 60mm f/5
Date: Morning of 9-7-09
Location: The Woodlands, TX
Processed with Nebulosity 1, Photoshop Elements 7 with Carboni Actions

The Butterfly's Back: IC 1318 Near Gamma Cygni

Photon-deprived and eager to try out a couple of new ideas, I set up last night under the 97% full moon. I have heard that narrowband filters allow one to image during the full moon. I wanted to try it. Second, I wanted to match the ED80 with the WO 0.8x II reducer/flattener and the Atik 16. Third, I wanted to try using my 9x50 finder as a guidescope.

The third idea failed. I would have to move the camera inside the tube to reach focus. Perhaps I will have to do surgery on the finder tube. The other two goals were met. The WO reducer works beautifully with the ED80 and the Atik 16, as is proved by this image. Finally, this 58x240' image was taken under the 97% full moon through an Astronomik 13nm narrowband Ha filter. Processed in Nebulosity 1 (drizzled) and Photoshop Elements 7.