Starship Asterisk*

NGC 1999: South of Orion

Explanation: South of the large star-forming region known as the Orion Nebula, lies bright blue reflection nebula NGC 1999. At the edge of the Orion molecular cloud complex some 1,500 light-years distant, NGC 1999's illumination is provided by the embedded variable star V380 Orionis. That nebula is marked with a dark sideways T-shape near center in this cosmic vista that spans about 10 light-years. The dark shape was once assumed to be an obscuring dust cloud seen in silhouette against the bright reflection nebula. But recent infrared images indicate the shape is likely a hole blown through the nebula itself by energetic young stars. In fact, this region abounds with energetic young stars producing jets and outflows with luminous shock waves. Cataloged as Herbig-Haro (HH) objects, named for astronomers George Herbig and Guillermo Haro, the shocks look like red gashes in this scene that includes HH1 and HH2 just below NGC 1999. The stellar jets push through the surrounding material at speeds of hundreds of kilometers per second.

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It's great to see Robert Gendler here again, and this is a splendid picture!

Ann

I like the face to the left of the image. God's looking at you.

Stunning....mysterious....more for Halloween....but great!!

and HH objects as well!

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Nice one. The HH object looks like a bipolar flamethrower with these colors. Maybe that's not such a bad analogy for them, anyway. If Rob pokes his head in here, question for him: Was this already in the pipeline or did you feel the need to revisit it after we put your older image of NGC 1999 in the calendar?

Revisited or not; I think it is a magnificent photo!

geckzilla wrote:Nice one. The HH object looks like a bipolar flamethrower with these colors. Maybe that's not such a bad analogy for them, anyway. If Rob pokes his head in here, question for him: Was this already in the pipeline or did you feel the need to revisit it after we put your older image of NGC 1999 in the calendar?

Thanks. Had this one on my short list for a while and in fact used the calendar image for the color. Details of course came from Subaru and Hubble data. Just yesterday I found a lot more data for this region in narrowband on the Subaru archive so I hope to expand it very soon.

BTW...thank you for all the nice comments above!

An absolutely incredible image of one of my favourite deep sky treasures of Orion! I'm also a big fan of Herbig Haro objects and nebulous YSO's, so the detail provided by the Subaru narrowband data is crazy epic! The only aspect of the image I don't like are the fake diffraction spikes, they look way too graphical and impossibly perfect.

Is there data for any planetary nebulae in the Subaru archive?

starsurfer wrote:The only aspect of the image I don't like are the fake diffraction spikes, they look way too graphical and impossibly perfect.

What makes you think they are fake? Both telescopes have secondaries supported by 4-vane spiders, so diffraction spikes like this are to be expected. They could be synthesized afterwards, of course. They don't show dispersion along them as we usually see.

My question is why they are all aligned. Unless both telescopes were operating in exactly the same orientation, I'd expect two sets of diffraction spikes at different angles to each other. Were the telescopes both operating at the same orientation? Did only one dataset have spikes? Were the spikes removed from one set? Or removed from both and synthesized?

Rob?

starsurfer wrote:An absolutely incredible image of one of my favourite deep sky treasures of Orion! I'm also a big fan of Herbig Haro objects and nebulous YSO's, so the detail provided by the Subaru narrowband data is crazy epic! The only aspect of the image I don't like are the fake diffraction spikes, they look way too graphical and impossibly perfect.

Is there data for any planetary nebulae in the Subaru archive?

Yep..they're fake. Doing these composites with markedly disparate data is very tricky. This is especially true when combining narrowband with broadband data and professional with amateur data. Often the stars end up a mess as was the case in this image. The best solution IMO was to use Neil Carboni's tools for star spikes to replace the brightest stars in the image. The tool does not replace or alter the star colors so that is real. This was a purely aesthetic adjustment for the stars and did not affect the remainder of the image.

Chris Peterson wrote:

starsurfer wrote:The only aspect of the image I don't like are the fake diffraction spikes, they look way too graphical and impossibly perfect.

What makes you think they are fake? Both telescopes have secondaries supported by 4-vane spiders, so diffraction spikes like this are to be expected. They could be synthesized afterwards, of course. They don't show dispersion along them as we usually see.

My question is why they are all aligned. Unless both telescopes were operating in exactly the same orientation, I'd expect two sets of diffraction spikes at different angles to each other. Were the telescopes both operating at the same orientation? Did only one dataset have spikes? Were the spikes removed from one set? Or removed from both and synthesized?

Rob?

I have looked at thousands of astroimages for nearly a decade and I'm quite good at recognising genuine diffraction spikes. I have developed an inbuilt fake diffraction spike detector!

starsurfer wrote:I have looked at thousands of astroimages for nearly a decade and I'm quite good at recognising genuine diffraction spikes. I have developed an inbuilt fake diffraction spike detector! :D

I agree, the lack of dispersion in the spikes suggests they are fake. Whether fake spikes look worse than real ones is a matter of personal aesthetics. I'd prefer no spikes at all, but this image was going to have them one way or another, so it makes sense for Rob to use them to his advantage as he described.