View Single Post
  #1  
Old 30-06-2020, 06:07 PM
Placidus (Mike and Trish)
Narrowing the band

Placidus is offline
 
Join Date: Mar 2011
Location: Euchareena, NSW
Posts: 3,719
The Flea in the Pussycat's Ear: Trifid SHO 17 hrs

With moral support from Geoff Smith, we've doubled the total exposure on the Trifid, with a view to better seeing the Herbig-Haro jet and the evaporative gaseous globule next to it.

20 inch PlaneWave. Red = SII, Green = H-alpha, Blue = OIII. 34 half-hour subs total, 17 with an FLI PL16803 from the other day, and 17 with an Aspen GC16M (same chip) from 4 years ago.

Big One Here

With North on the right, the Trifid becomes the face of an angry tom-cat, that has been in a fight. The cat's right ear (our left, and bent toward the nose because of the fight - see close-up) has a very conspicuous Herbig-Haro jet (like a yellow-green thorn, heading off toward 2 o'clock from the ear). The jet is about 16 sec arc long and less than 1.5 sec arc wide. Just below it is a thin dark nick, a column of dust in the core of the the evaporative gaseous globule, the two features reminiscent of a snail's antennae.

To the right of the cat's head is a large blue reflection nebula, which has fought its way through the OIII filter. In real life it would be much brighter.

The Trifid is hugely brighter than its surroundings. There is some interesting nebulosity about, which we've brought out by selectively masking the bright central region and brightening the countryside.

Notice the bright double star on Tom's nose. Close inspection shows it is quadruple, there being two faint companions. But if we look at the raw stack, before stretching (see attached thumbnail of just these 4 stars, with Ha mapped to red and OIII to aqua), one of the two bright stars itself resolves into a double (about 3 sec arc) of strongly differing colours.
Attached Thumbnails
Click for full-size image (Trifid Thumb SHO 17h30 total.jpg)
168.4 KB155 views
Click for full-size image (HH Jet.jpg)
166.4 KB135 views
Click for full-size image (Nose Ha Red OIII Aqua.jpg)
76.8 KB122 views

Last edited by Placidus; 30-06-2020 at 06:44 PM.
Reply With Quote