APOD: Sharpless 115 (2013 Jun 14)

[APOD Robot]

Sharpless 115

Explanation: Sharpless 115 stands just north and west of Deneb, the alpha star of Cygnus the Swan in planet Earth's skies. Noted in the 1959 catalog by astronomer Stewart Sharpless (as Sh2-115) the faint but lovely emission nebula lies along the edge one of the outer Milky Way's giant molecular clouds, about 7,500 light-years away. Shining with the light of ionized atoms of hydrogen, sulfur, and oxygen in this Hubble palette color composite image, the nebular glow is powered by hot stars in star cluster Berkeley 90. The cluster stars are likely only 100 million years old or so and are still embedded in Sharpless 115. But the stars' strong winds and radiation have cleared away much of their dusty, natal cloud. At the emission nebula's estimated distance, this cosmic close-up spans just under 100 light-years.

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[Boomer12k]

Clouds in space....yet stars shine through....
Lovely Picture.

:---[===] *

[emc]

some of the clouds remind me of a football... American that is! or an eye... or flying saucer... or Bugs Bunny's rocket to Mars

[Roland]

Would someone please explain the optics of why nearer and brighter stars have a light cross, the spikes that come out from the star?

[geckzilla]

Would someone please explain the optics of why nearer and brighter stars have a light cross, the spikes that come out from the star?

They're called diffraction spikes. Take a look at this Wikipedia article. http://en.wikipedia.org/wiki/Diffraction_spike
Look at the image of the Newtonian reflector. The supports labeled 3 are causing the spikes.

[Insert Username Here]

Would someone please explain the optics of why nearer and brighter stars have a light cross, the spikes that come out from the star?

They're called diffraction spikes. Take a look at this Wikipedia article. http://en.wikipedia.org/wiki/Diffraction_spike
Look at the image of the Newtonian reflector. The supports labeled 3 are causing the spikes.

Also, see here..http://en.wikipedia.org/wiki/Lens_flare

[retrogalax]

I like very much the different colors of the stars in this picture.

[Jim Leff]

I attended U of Rochester in the early 1980's, and while I had a life-long interest in astronomy, I was dismayed to discover that serious astrophysics courses required hardcore math skills I lacked. So I studied other topics, including, in my senior year, "The Physics of Music", taught by Professor Sharpless, who had a lifelong love of music and considered this seminar (which was very hands-on with equipment like acoustic spectrum analyzers) a labor of love. He was an incredibly kind-hearted, down-to-earth, personable fellow, and if there was an Internet back then, I'd have have quickly looked him up and found out who he actually was. But this was Rochester, not, like, Yale, so one didn't expect one's professors to be celebs.

So I never found out, but really enjoyed my time with him. There was something personal and heartfelt about that class that was far from the norm. I couldn't attribute it to anything, being just a kid at the time, but I now understand it was the palpable patina of the oh-so-rare combination of stature and earnestness. Eminence without arrogance, pomposity, condescension or cynicism. Prof Sharpless obviously retained his child-like earnest eagerness about science, and he treated everyone like a colleague. He was a low-gravitas individual (LGI?)

I went on to degrees in things like philosophy, music, and politics, but never lost interest in astronomy, though I still lack math skills to this day. I'm a faithful APOD viewer, where every reference to Prof. Sharpless and his famous catalog gives me a sad smile. It was great to be in his class, but, oh, man, how I wish I'd milked more astronomy stories from him, lobbied for an invitation to the observatory, etc (he mentioned something about taking the class there some Saturday, but it never came together). I just didn't realize who he was - though, on a deeper level, "who he was" did quietly inspire me.

I hope this brief remembrance wasn't inappropriate here.

[owlice]

Jim, I think it lovely and appropriate; thank you for it.

[Chris Peterson]

Would someone please explain the optics of why nearer and brighter stars have a light cross, the spikes that come out from the star?

Besides the other answers you have, keep in mind that this is purely an effect related to the apparent brightness of a star. It has nothing to do with distance, and in general there's no way in an image like this to determine which stars are nearer and which are farther away.

[Anthony Barreiro]

I attended U of Rochester in the early 1980's, and while I had a life-long interest in astronomy, I was dismayed to discover that serious astrophysics courses required hardcore math skills I lacked. So I studied other topics, including, in my senior year, "The Physics of Music", taught by Professor Sharpless, who had a lifelong love of music and considered this seminar (which was very hands-on with equipment like acoustic spectrum analyzers) a labor of love. He was an incredibly kind-hearted, down-to-earth, personable fellow, and if there was an Internet back then, I'd have have quickly looked him up and found out who he actually was. But this was Rochester, not, like, Yale, so one didn't expect one's professors to be celebs.

So I never found out, but really enjoyed my time with him. There was something personal and heartfelt about that class that was far from the norm. I couldn't attribute it to anything, being just a kid at the time, but I now understand it was the palpable patina of the oh-so-rare combination of stature and earnestness. Eminence without arrogance, pomposity, condescension or cynicism. Prof Sharpless obviously retained his child-like earnest eagerness about science, and he treated everyone like a colleague. He was a low-gravitas individual (LGI?)

I went on to degrees in things like philosophy, music, and politics, but never lost interest in astronomy, though I still lack math skills to this day. I'm a faithful APOD viewer, where every reference to Prof. Sharpless and his famous catalog gives me a sad smile. It was great to be in his class, but, oh, man, how I wish I'd milked more astronomy stories from him, lobbied for an invitation to the observatory, etc (he mentioned something about taking the class there some Saturday, but it never came together). I just didn't realize who he was - though, on a deeper level, "who he was" did quietly inspire me.

I hope this brief remembrance wasn't inappropriate here.

Thanks Jim for sharing these memories and this tribute to Professor Sharpless. You're very fortunate to have learned from him.

[Jim Leff]

Yes, but, sheesh, I could have learned astronomy from him! Would it have killed me to polish my math skills?

Sigh....