Eta Carinae and the Homunculus?

cloud_cover · Post by **cloud_cover** » Mon Feb 21, 2011 1:01 am

Just wondering if the Eta Carinae nebula and the Homunculus are visible in a telescope?
I can't seem to find anything on stellarium on it - it just points me to a patch of stars and empty space.
I also can't find anything on the angular size of the Eta Carinae Nebula and the Homunculus within it - does anyone know what its size is?
I'm thinking of trying some imaging on it

Only problem - non-modified DSLR and I think its a largely HA region.....

orly_andico · Post by **orly_andico** » Mon Feb 21, 2011 1:12 am

I've seen the Eta Carina Nebula through 10x50 binoculars in a dark-sky site in a province south of Manila (about 100km). It's pretty large and amazing. Looked even better through the 10" f5 dob. With something like your VC200L though you can't see the whole extent because it's quite large.

Post by **weixing** » Mon Feb 21, 2011 9:36 am

Hi,
The Eta Carinae Nebula is visible in Singapore. The Homunculus nebula is not visible in Singapore and it's very small, but not sure will it show up in image.

Anyway, the Eta Carinae Nebula is quite big and can be image in Singapore... I shoot it once when I start learning astrophotography 6 years ago... only a few images stacked using my previous Sky-Watcher 6" F5 Newtonian with my previous non-mod Canon 300D DSLR... may be I should try it again. I found the old thread I posted: http://www.singastro.org/viewtopic.php?t=1852

Have a nice day.

cataclysm · Post by **cataclysm** » Mon Feb 21, 2011 12:17 pm

Yes its a huge object, spanning 4 degrees, best view it with a richfield refractor or a bino. It climbs no higher tha 30 degree, so viewing it at our elevation has alot to do with the sky conditions. A LPS or Nebula filter will help to accentuate the nebulous region. I shot this recently in narrowbands using the Baby Q and 350D, and it shows about 3 degree fov, not quite able to cover the entire field.
http://www.singastro.org/viewtopic.php?t=9261

Post by **weixing** » Mon Feb 21, 2011 1:01 pm

Hi,
Your VMC200L will only cover a small portion of the Eta Cartinae Nebula, so I suggest you should try imaging the bright nebula in the centre... the total exposure time of my image is less than 4min with a F5 scope using a non-mod DSLR at ISO 1600... you should be able to get a similar exposure with 12min of exposure time if using similar setting.

Happy imaging.

Have a nice day.

orly_andico · Post by **orly_andico** » Mon Feb 21, 2011 1:21 pm

better yet, use your 70-200 2.8 stopped down to f/4.

cloud_cover · Post by **cloud_cover** » Mon Feb 21, 2011 2:00 pm

Yeah, at 200mm I'll be doing a pic size of about 400x600arcmin, which is a 6.6x10deg field. Unfortunately no filter will fit in front of the 77mm lens!
My ED80 will give me about 163x245arcmin, which I think will barely fit the whole nebula into one field, but I'll be able to use filters thanks to the 2" drawtube. Only catch - I need that field flattener or it will be an egg storm out there.....
Weixing: Do you mean a single 12min exposure or total integration time of 12mins? Thankfully the VMC is a f9.75 scope and I have the f/6 reducer so hopefully I don't need to expose quite that long
Still hoping to catch some HA data with the D700 - its very blocked but not fully blocked. Never know

Anyone willing to lend a 2" HA filter for maybe a week or so to try?

Post by **weixing** » Mon Feb 21, 2011 2:31 pm

Hi,

cloud_cover wrote: Weixing: Do you mean a single 12min exposure or total integration time of 12mins? Thankfully the VMC is a f9.75 scope and I have the f/6 reducer so hopefully I don't need to expose quite that long
Still hoping to catch some HA data with the D700 - its very blocked but not fully blocked. Never know
Anyone willing to lend a 2" HA filter for maybe a week or so to try?

Try total integration of at least 12min with.. may be 1min exposure per frame... actually, why don't you just shoot 60 frames of 1min exposure per frame??

Anyway, if your DSLR is non-mod, forget about HA filter... I think it'll make it worst as you might not even get some nebula of other wavelength.

Have a nice day.

Post by **rcj** » Mon Feb 21, 2011 8:51 pm

The Homunculus is extremely small. In one OZ star party, I have heard people looking at it with 20-25" dobs, though personally I have not seen it yet.

Post by **weixing** » Mon Feb 21, 2011 9:58 pm

Hi,

rcj wrote:The Homunculus is extremely small. In one OZ star party, I have heard people looking at it with 20-25" dobs, though personally I have not seen it yet.

Can see it using 18" under dark sky as We (rlow, elton and me) saw it using Elton 18" Obsession UC in Malaysia... a very orange star with 2 "ear"... very interesting view.

Have a nice day.