June 27, 2010
Rory Glasgow and I learned that we both imaged the Trifid in the last two weeks. He used a Canon DSLR attached to a Takahashi Epsilon 200 Hyperbolic astrograph, and I used an SXVF-H9C through an Orion 6" I-Newt. Through the magic of Registar, we have here combined our data. This is better than both our independent shots. Combined, the coma in my data is mostly covered up, and the light and colors are deeper and richer. Rory's data comprised 11x2' with a Canon EOS Rebel XS (1000D) at ISO-800. I have posted two versions of the same combined image, one stretched more than the other.
June 20, 2010
The Trifid Nebula, or M20. It is about 5,400 light years away in the constellation Sagittarius. It stands between our Sun and the center of our galaxy, so when we look towards the Trifid, we are looking toward the galactic center. It's a busy place. The Trifid itself is also busy. The red glow comes from ionized hydrogen. The two bright stars in the middle of the red portion excite the hydrogen within the cloud, causing the glow. The blue is reflected starlight. The Trifid is also a stellar nursery. Some of the stars in the image were formed from the very cloud that they now illuminate.
This image was taken with the Orion 6" Inewt and the SXVF-H9C. Flats and bias frames applied. No filter was used, and no coma corrector (I don't have one yet). The image is a stack of 25x8' exposures for a total of 200 minutes. Capture and pre-processing was with Neb 2; color conversion and stacking in Maxim; and touchups in PS3. I have posted two versions, post-processed slightly differently in PS3.
Just for kicks, check out my first image of the Trifid, taken three years ago in June 2007:
This was taken with the DSI Pro, unguided through an Orion 100mm f/6 achromat. I can't remember all the details of the image, but I believe it's about 10 minutes worth of 10-second exposures.
June 18, 2010
Photon-deprived, I set up last night despite the haze. I took an hour's worth of my old nemesis, Arp 117, and more of the Trifid. No time to process yet, so we'll see. The sky was never really clear, and I could see wispy clouds floating by in the dark. But we've had clouds every night for a month. Just had to get out.