Starship Asterisk*

Copyright: Robert Gillette

Larger Image: http://astrob.in/full/237923/0/

Flame & Horsehead nebulae in HaRGB

Copyright: Robert Gillette

Larger images: http://astrob.in/full/234713/B/

Splendid, Piotr. You caught it all.

Bob Gillette

Visually dramatic, but not so mysterious in origin. As Wkipedia notes, there is a long history of igneous intrusion in the area. A large igneous bulge almost certainly caused the uplift. Erosion of differentially resistant rock layers (hard quartzite vs. softer sediments) accounts for the ringed app...

Chris,

Further on color balance. You're right, I would not have chosen purple stars. Many/most of us, unless we're doing narrowband imaging, color calibrate images on a G2V sun-like star, which produces what the human eye would call a natural color balance with no room for debate, or taste.

Bob

Chris,

As to color balance, thank you for the explanation, but I am an imager and I know what a DSLR is. I use two SX OSCs and a mono QSI. The color balance is off. The image is too purple. Stars are generally not purple.

Bob Gillette

Not a bad wide angle view if PANSTARRS, but the color balance is off. The comet submissions on Asterisk contains better images.

Bob

Thank you!

Bob

PANSTARRS in Cepheus 4 May
http://tinyurl.com/cx6yewu
Copyright: Bob Gillette

Fires don't sit in the same place when they burn. They move. Kind of like a comet. Taking 22 images of a comet 24 hours apart then combining the image stack would give the improbable impression of 22 comets all in a row. So perhaps the earth at night image recorded 22 times (or some smaller but sign...

This is a beautiful image of wasted energy, notably from standard streetlights designed to achieve a broad beam, but in the process emitting 5% or more of their light upward. The International Darksky Association estimates in the U.S. alone, energy wasted in this manner costs $2.2 billion. Next time...

Heart of the Heart Nebula http://tinyurl.com/9myzlyh Copyright: Robert Gillette Central portion of IC 1805 in Cassiopeia, with open cluster Melotte 15 at upper center. For higher res and details, please see URL at Astrophotogallery.com Thanks for looking, Bob Gillette Ossipee NH IC 1805 10 Sep 12-2...

M 51 SN 2011dh 03 June 2011

95 minutes on 03 June 2011.

http://tinyurl.com/6c49fvh

Copyright: Robert Gillette

Good. Now to Chris Peterson's note that silicon does in fact show strong emission lines in some nebulae. Are these emissions strong enough that amateur equipment could capture them? If so, are silicon emission filters commercially available in the usual sizes?

Tnx,

Bob

I wouldnt attempt to explain Silicon Valley, but I do think the good folks at APOD, not being infallible, owe a small correction, or as news people call it in a vivid metaphor that conveys the pain involved in publicly acknowledging a mistake, a "skinback."

Bob

The explanation of this image of NGC 1499 says that "silicon" is mapped to red. Ionized silicon? That's interesting. Who am I to question the professional astronomers who write these things? But somehow "sulfur" might make more sense.

Bob

NGC 6914

Copyright: Robert Gillette

http://tinyurl.com/4nhldy9
[attachment=0]NGC 6914 399 Min Jul-Aug 10 - 17 Feb 11 FNL 800pxLO.jpg[/attachment]

Martin, Thanks for this information. If the mag 12 star referenced has an annual proper motion of 0.229" in DEC, then the movement over four years would have been 0.916" or, at your image scale, just over one pixel. The actual movement looks a bit more dramatic than that, but maybe it isn'...

Martin Fiedler's M 1 GIF is very interesting. A star is also moving at the lower right. Does this reflect real motion over a 4-year period?

Bob Gillette

Ann,

You're right about the dust lane. I hadn't noticed that. Indeed, that should solve the mystery. Well observed!

Bob

On the structure of NGC 1514, I found this on the Wide-Field Infrared Survey (WISE) site, which includes a very weird infrared image of the object: "The object is actually a pair of stars -- one star is a dying giant somewhat heavier and hotter than our sun, and the other was an even larger sta...

Ann, Thank you for that information about the central binary star of NGC 1514, which goes way beyond what I knew about it. I can claim, however, to have experienced a small rush of curiosity,though one not pursued, as to why the central star was so white, when most often the central stars of planeta...

Ann, Yes, it is indeed NGC 1514, aka the Crystal Ball Nebula (something it apparently resembles when viewed visually.) IMy apologies, I seem to have dropped the title on the cutting-room floor. This planetary is unusual, in that it appears to envelop a tightly orbiting pair of stars, one a dying gia...

http://tinyurl.com/4lk36l5

Copyright: Bob Gillette

This one's for Ann

Thank you, Ann.