Two years ago, when I first got my 200 mm/8" Zhummel dobsonian, among the targets I most eagerly wanted to see was the Rossette nebula (aka Caldwell 49). The Rosette is some 5000 light years away from us and not far from a lovely star cluster known as Caldwell 50/
NGC 2244 which is the closest easily visible reference point.
I'd seen those wonderful bright red and orange rose-like images, and naively hoped to see a gray version on my
dob. Keep in mind, my backyard is under
Bortle 5 skies, and at the time, I was strictly star hopping with my 8x50 finder scope, and the stock 30 mm and 9mm eyepieces. Thus, I was never entirely sure I was looking at the right spot, and every attempt ended in frustration not realizing I was looking at it, I just didn't know it.
Back then, on the old forum, J Gardavsky generously advised on how to find it, so I bought a Lumicon OIII filter, but still nothing.
Last night was moonless, transparency was pretty good with many objects easily visible to the naked eye, and best of all, it wasn't freezing cold for once. I took the Z8 out and replaced the finder scope with my homemade Celestron StarSense Explorer phone cradle, dialed in some tricky targets like
Messier 110 and M32, and quickly realized it was an excellent moment to try the Rosette once more.
Tapped Caldwell 49 into the SSE
app, pushed to the suggested spot, waited a couple of seconds while the
app figured out where I was, adjusted slightly, green light on. Looked through my Celestron 32 mm Ploessl, and nothing. Stars with a bland dark gray background. Moved the
OTA slightly left and noticed some stars were obstructed by a dull gray smudge. Screwed on the OIII filter which darkened everything almost too much, but the smudge was now more "contrasty" black. Moved the
OTA around and sure enough, I finally saw the Rosette. Took the filter off now that I knew what I was looking for, and enjoyed viewing the faint dark gray cloud with a cheap plastic 25 mm Celestron eyepiece which somehow gives some of the best views of the sky with my Z8.
The 25 mm eyepiece, by the way, is the stock eyepiece that came with the Celestron DX102AZ refractor, and oddly, Celestron nowhere says what type it is. Maybe a Kellner? Whatever it is, abundant plastic and all, stars are tack sharp dots on it!
What I wish I'd understood two years ago:
+ You need a good clear night.
+ Low power eyepieces are best. 37.5X and 48x in my case. It's bigger than you think.
+ Filter is nice to have but not need-to-have.
+ Know that the cloud is camouflaged in almost the same dark gray as the background sky.
+ The give away are the missing stars in the background as you slowly pan around. Slowly. Patiently.
+ I had looked at the right spot two years ago, I just didn't know it.
Next step, try with my Celestron 102AZ refractor.
Finally, thank you again J Gardavsky for your good advise two years ago.
https://en.wikipedia.org/wiki/Rosette_Nebula