Antenna Galaxies

[cometcatcher (Kevin)]

Antenna galaxies NGC4038/4039. I've been struggling for sky time since I started this project in March. Transparency was not the best either. But I need to finish it so here it is.

I've also figured out why my bright stars are elongated 2 O'clock / 8 O'clock. It's caused by mirror slap vibration. The 1100D has no mirror lockup ability. The only way around this that I can think of is to take less subs per total integration time. Less mirror slaps = less artifacts. Or use another camera.

GSO 10" F4 Newtonian, Canon 1100Dfs, 565 x 30 and 45 sec subs for a total of about 5 hours.

Bigger at Astrobin ----> https://astrob.in/344716/0/

From Wiki " The Antennae Galaxies, also known as NGC 4038/NGC 4039, are a pair of interacting galaxies in the constellation Corvus, 45 / 65 million light years away. They are currently going through a starburst phase, in which the collision of clouds of gas and dust, with entangled magnetic fields, causes rapid star formation. They were discovered by William Herschel in 1785.

[LewisM]

Nice one Kevin!

[RickS (Rick)]

Looks good, Kevin! One of my favourite objects.

[alocky (Andrew lockwood)]

It’s a fascinating pair and I really like the detail and colour in the centre. As for the mirror flip-up - although my OMs and Nikon’s always had a mirror lock up or pre-fire, I saw other less fortunate photographers resort to holding a hat in front of the OTA for a few seconds. Back in the days of hand-guiding and hour long exposures this was not a problem, but if you are planning on leaving the thing running unattended I appreciate it’s not a helpful suggestion.
Cheers
Andrew.

[doppler (Rick)]

Nice work there Kevin, the colours are really coming out in the galaxy's arms. You've done well to get 5 hrs on it with Mackay's dodgy weather, but if you want to minimize the mirror slap by using fewer subs for the same integration time you will have to bite the bullet on auto guiding.

I don't know why they dropped the mirror lock function in the 1100d's, my 450d has it, but you have given me the idea to remove the mirror when I astro modd my spare 1100d and hopefully I don't ever have to use the eye ball viewfinder.

[cometcatcher (Kevin)]

Originally Posted by LewisM

Nice one Kevin!

Thanks Lewis!

Originally Posted by RickS

Looks good, Kevin! One of my favourite objects.

Thanks Rick! It's an interesting object for sure. Something I'll have to revisit with better conditions.

Originally Posted by alocky

It’s a fascinating pair and I really like the detail and colour in the centre. As for the mirror flip-up - although my OMs and Nikon’s always had a mirror lock up or pre-fire, I saw other less fortunate photographers resort to holding a hat in front of the OTA for a few seconds. Back in the days of hand-guiding and hour long exposures this was not a problem, but if you are planning on leaving the thing running unattended I appreciate it’s not a helpful suggestion.
Cheers
Andrew.

Thanks for the suggestions Andrew. Once upon a time in the days of film I would perform the "hat trick". But this is all automated so a bit tricky to do it now.

Originally Posted by doppler

Nice work there Kevin, the colours are really coming out in the galaxy's arms. You've done well to get 5 hrs on it with Mackay's dodgy weather, but if you want to minimize the mirror slap by using fewer subs for the same integration time you will have to bite the bullet on auto guiding.

I don't know why they dropped the mirror lock function in the 1100d's, my 450d has it, but you have given me the idea to remove the mirror when I astro modd my spare 1100d and hopefully I don't ever have to use the eye ball viewfinder.

Thanks Rick. The eye viewer is pretty useless for astro anyway. I plug it up with cardboard so no stray light can get in and just use liveview or take short subs.

[raymo]

Very nice Kevin, but I note the strong banding in the Astrobin version.

Rick, I think the fact that I paid AU$297 new for my 1100D including the 18-55mm kit lens answers your question.
raymo

[cometcatcher (Kevin)]

Originally Posted by raymo

Very nice Kevin, but I note the strong banding in the Astrobin version....
raymo

Yes Ray, I was struggling with colour banding on this image. My 1100D (and probably others) is very noisy at summer temperatures. This summer was particularly hot at night with temps consistently in the high 20's which brings out all the warts.

One way of combating banding and other uneven cmos illumination is to rotate the camera 180 degrees and shoot an equal number of subs. This helps smooth out uneven sensor illumination. But I didn't have the sky time to do it. We are back into showers now and the only time we seem to get a good sky is at full moon!