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NGC 6742

Started by Rod Kaufman, 10/11/2015 09:48AM
Posted 10/11/2015 09:48AM | Edited 10/11/2015 09:50AM Opening Post
A challenging object for DSO observers in moderately lighted polluted skies is NGC 6742, a fairly large but at magnitude 13.4, a fairly dim planetary nebula currently well-placed for observation in Draco. It took several attempts for me to locate it in the field of view of my 16" f4.5 dob in front of my light polluted home but I managed to pull it out of a photon fog with a ES 24mm 82AFOV eyepiece and a Lumicon 0111 filter. I spent most of the night on Saturday evening(10-10-15) enjoying the views of planetary objects with the aforementioned combination of eyepiece/filter usage but changing over to a 10mm Ethos once the object was identified.
The challenge for observers on NGC 6742 is the low surface brightness, pegged by the DSO browser app at 20.82:
http://dso-browser.com/dso/info/NGC/6742/planetary-nebula
At least one imager notes this object is "quite difficult to capture":
http://www.myastrostuff.com/pncollection/ngc6742.htm
Nice to know they have their challenges, too! grin
Posted 10/11/2015 10:40PM #1
Woo Hoo! I got it with the 29-inch using 13mm Ethos at 256x using DGM N filter. Yep - it's challenging, although I was quite able to "find" it using the 31mm Nagler at 107x and no filter. I felt I could see structure and gratified that the picture you linked to does indeed show a darker off-center spot in there. My "push to" has been unreliable for a year and getting worse. So I spent the next hour spinning the az full-circle and find I have to overshoot more and more each circuit to get back to zero (in either direction!) I conclude the encoder must have a bad spot(s) and is dropping counts. Alt seems OK. Glad I have (probably) isolated that problem and is addressable. These elusive objects NEED good encoders! Sure want to know you are ON the object to concentrate on trying to SEE it! I felt like a fool spinning a 29-in scope around and around with the lights on! The deer outside started snorting and I was afraid they would jump in! Mating season... Tom

29-inch Dob in a dome
36-inch upgrade soon
LUNT 80/80 solar scope
FLI 6803 cam
APM 100mm APO Binos
JMI RB-16 Night Vision Binos
Zeiss 20x60 IS binos
Posted 10/13/2015 06:13PM #2
P.S. that dso-browser is Great! Thanx - I didn't know that can just be called up and ... Browsed. Tom

29-inch Dob in a dome
36-inch upgrade soon
LUNT 80/80 solar scope
FLI 6803 cam
APM 100mm APO Binos
JMI RB-16 Night Vision Binos
Zeiss 20x60 IS binos