View Full Version : A Very Dusty Horsehead

Colorado CJ
22-Feb-2020, 17:24
We finally a clear night here in Northern Colorado, so I was able to use my new scope again!

I decided to shoot the Horsehead and Flame.

As I am still trying to figure out the best way to use my new RASA 11, I used two different cameras this time. I used a ZWO ASI183MC Pro for the RGB and a ZWO ASI183MM Pro for the H-Alpha. Instead of using a filterwheel, this time I used a 6nm 1.25" h-alpha filter with a ZWO adapter screwed inside the ZWO m42 extension which seemed to work very well. I had no vignetting at all and the 6nm filter seems to work well at f2.2.

Anyway, here is what I got with 3.1 hours total integration. This is the deepest I've ever imaged the Horsehead, lots of dust compared to my last try at this part of the sky. My normal imaging scope used for this was a Stellarvue SV80, which at f7, would have taken me 31 hours of integration to get what I got with just 3.1 hours with the RASA. I am LOVING this scope!

This one is best viewed on the Astrobin link below to see a more detailed view. (click on small square image, then on Astrobin click on the image again to get a full screen view)

125, 45 second RGB images at gain 54
60, 90 second H-Alpha images at gain 111

EQ6-R Pro
ZWO ASI290mm Mini Guide Scope

https://live.staticflickr.com/65535/49570604671_dbf71865f5_o.jpg (https://flic.kr/p/2iwoiKM)HorseHead-Final-Small (https://flic.kr/p/2iwoiKM) by Colo CJ (https://www.flickr.com/photos/184532879@N08/), on Flickr

https://astrob.in/nj1c2s/0/rawthumb/gallery/get.jpg?insecure (https://astrob.in/nj1c2s/0/)

Peter Lewin
24-Feb-2020, 06:45
No idea what you are saying about equipment and integration, but that is a remarkable and wonderful image.

Tin Can
24-Feb-2020, 07:17
Yes, nice image

We idiots need hot links on almost every bit of jargon you wrote

24-Feb-2020, 08:40
just epic, gorgeous results, the universe is yours!

Leszek Vogt
24-Feb-2020, 10:39
Excellent work, CJ. Send these guys to astro forum.....puhleese. :>)


C. D. Keth
24-Feb-2020, 10:45
Now that's infinity focus.

27-Feb-2020, 23:21
Think it looks more like Jar Jar Binks.

28-Feb-2020, 00:46
Great image CJ!

The Celestron RASA 11 - https://optcorp.com/products/celestron-11-rasa?msclkid=04e8faf8aa591ceebba6a4a0152e9b85 - is a great imaging scope. Do you work from a fixed observatory or do you transport it to the field? If the latter, how long does it take you to set-up?

I got to get back into astronomy - still working with a 10" Meade LX50/


28-Feb-2020, 12:06
Whoa, that's far out man. Seriously, that's cool.

Drew Wiley
28-Feb-2020, 12:24
Alas, I have neither the time nor funds to get into astrophotography. But it looks so interesting. Out here, the highest road is atop the White Mountains just east of the Sierra crest, near the Bristlecone reserve, where I've seen trailers with pretty big telescopes, up to 16 inch reflectors. But any high pass is good if weather permits and forest fire smoke is not active. I'm glad you've found a rewarding niche.

29-Feb-2020, 11:54
Actually deep sky astrophotography using CCD and digital cameras do not require dark sky or high elevation observing sites. Back in the late '90's a local bay area amateur routinely got full color images similar to CJ's from Monte Bello Open Space Preserve on the Peninsula and from his backyard in Castro Valley that were indistinguishable from images produced by professional observatories using much larger telescopes. Of course observing/imaging from a dark high spot doesn't hurt and for me is actually a necessity since my scope is a “push to” and not a “go to.” To polar align the scope and set the circles I have to first center Polaris and then center a star that lies on or near the celestial equator such as Mintaka in Orion's belt. Once the scope is properly aligned I can manually “push” the scope to the coordinates of the celestial object of interest. The SCT is not as friendly to “star hopping” as the Dobsonian is so I learned to use the coordinates instead. Nowadays the mounts and tracking are very sophisticated so it is not necessary to visually see Polaris or Mintaka to polar align. But relatively dark sky sites are still available here in the bay such as the summit of Mount Diablo where I often observed from and Fremont Peak which is a bit of a drive south of San Jose. Mt Tam is also a dark sky site but I have never observed from there.


29-Feb-2020, 14:56
Amazing what technology and skill can do (coming from someone happy to not leave the lens cap on). Beautiful Colorado CJ!