Triangulum Galaxy (M33)

[Thalestris24]

Hi

Yeah I always stack with calib frames. I'll look at what I've got tomorrow - I've stopped M33 for tonight but acquired 4 x 900s to add to the data set. Moving on to other objects now . Oh, I extended my 'lens hood' earlier so that might have cut down on the streetlight gradient. Will inspect what I have by the cool clear light of day! I'll upload a fits tomorrow.

Cheers

Louise

[tdnicholls]

Ok, would not have chance to look at the fits file till tomorrow...

[Pete Presland]

excellent image, great image scale!

[Thalestris24]

Ok, would not have chance to look at the fits file till tomorrow...

Hi again

Well I stacked and processed the 4 x 900s from last night and this is the best I could get out of just them:

Complete with satellite trail! Tut!

Here is a single sub if you fancy to have a look :

L_Bin1x1_900s_2014-08-26_23-17-02__-6C.fit

Cheers

Louise

[x6gas]

To be honest Louise, I think you just need more subs.

1200 - and even 900 - second subs might be too long too.  The light pollution overwhelms everything so in light polluted skies you need shorter subs than at a dark sky site.

I used mostly 600s subs for my M33 a year or so ago but often with galaxies now I try shooting 300s subs and take it from there (see http://www.ir-astro.com/galaxies.html).

The good news is that M33 is around for a bit now so you've got time to grab some more data, whether permitting of course!

[Thalestris24]

Hiya

Yeah, you're probably right! This has been my first serious attempt at a galaxy so I'm trying to learn how to capture and process them. I actually have lots of M33 subs - the 4 x 900s were just from last night. Unfortunately my limited view of the sky means that I may not get many more goes at M33 this year (I can only see to the east-north east). I have a mix of M33 subs from 300s upwards so maybe I'll try and stack them all together. I think I've fnally got rid of most of the nearby streetlight gradient by extending my 'lens hood' a bit . That won't help with the earlier subs but at least I have something to work on.

You're images are awesome!

Thanks

Louise

[tdnicholls]

Hi Louise,

Agree with x6gas here, you may be better off with 20 or so 300s subs, that is what I had and you scope is faster - lots of shorter subs should bring better results and can capture them all in one night.

That sub is very bright and you are blowing out a lot of the fainter detail, for comparison here is a single 300s from my M33

https://www.dropbox.com/s/ub7o5ezcz1u144t/-19.8C_300sec_1x1_Light_frame3.fit?dl=0

You only run the camera at -6? I run mine at -20 which is fine provide ambient is below 20c

Cheers

[tdnicholls]

I used mostly 600s subs for my M33 a year or so ago but often with galaxies now I try shooting 300s subs and take it from there (see http://www.ir-astro.com/galaxies.html).

Some fantastic images there Ian

[Thalestris24]

Hi Louise,

Agree with x6gas here, you may be better off with 20 or so 300s subs, that is what I had and you scope is faster - lots of shorter subs should bring better results and can capture them all in one night.

That sub is very bright and you are blowing out a lot of the fainter detail, for comparison here is a single 300s from my M33

https://www.dropbox.com/s/ub7o5ezcz1u144t/-19.8C_300sec_1x1_Light_frame3.fit?dl=0

You only run the camera at -6? I run mine at -20 which is fine provide ambient is below 20c

Cheers

Hiya

Yeah, yours is much darker than mine and well over to the left. So it looks like I've been making a fundamental error by taking such long exposures I suppose if I was at a dark site they'd be fine! I did start doing M33 with 300s then 600s subs but couldn't see much which was why I upped it. Oh well, live and learn! So, should I do lots of 300s or 600s subs? 300s better? I find it hard to judge!

Yeah, I haven't been running the cooler as low as I should/could. It's because when I first got it I was being tentative as it was my first cooled camera. But having taken lots of subs of various objects I just left it at -5 rather than mix things up.

Thanks for all the advice and help, guys!

Louise

[tdnicholls]

Hiya

Yeah, yours is much darker than mine and well over to the left. So it looks like I've been making a fundamental error by taking such long exposures I suppose if I was at a dark site they'd be fine! I did start doing M33 with 300s then 600s subs but couldn't see much which was why I upped it. Oh well, live and learn! So, should I do lots of 300s or 600s subs? 300s better? I find it hard to judge!

Yeah, I haven't been running the cooler as low as I should/could. It's because when I first got it I was being tentative as it was my first cooled camera. But having taken lots of subs of various objects I just left it at -5 rather than mix things up.

Thanks for all the advice and help, guys!

Louise

Hi Louise,

Think most of us have been there, with just an LP I would not normally go greater than 300s for most targets these days. The 600+ subs are for when I use my Ha filter and can go up to 30min subs then.

Try 300s to start with, your setup that should capture something but may not really see it until processing time. Has APT got a stretch feature? Been a while since I looked at it.

Look forward to the results of the next session, I am on Astronomyshed more than SGL, normally in chat specially if imaging.

Cheers

[lensman57]

Hiya

Yeah, yours is much darker than mine and well over to the left. So it looks like I've been making a fundamental error by taking such long exposures I suppose if I was at a dark site they'd be fine! I did start doing M33 with 300s then 600s subs but couldn't see much which was why I upped it. Oh well, live and learn! So, should I do lots of 300s or 600s subs? 300s better? I find it hard to judge!

Yeah, I haven't been running the cooler as low as I should/could. It's because when I first got it I was being tentative as it was my first cooled camera. But having taken lots of subs of various objects I just left it at -5 rather than mix things up.

Thanks for all the advice and help, guys!

Louise

Hi Louise,

Drop the sub length to 300s and go for a lot of subs if possible to overcome the noise. M33 is not at all easy due to its low surface brightness and I have found it to be quite a noisy beast too.

I know the problem you have with your window and the LP so you may have to do this over a few nights if this " summer " weather permits. I believe there is another dead hurricane leftover that is heading our way for the weekend from the Atlantic. I did a test of my new scope and M33 last night and I could have gone for 900 ~ 1200s subs but I did 600s and it sort of worked reasonably well but your LP maybe different to mine.

Regards,

A.G

[Thalestris24]

Hi Louise,

Think most of us have been there, with just an LP I would not normally go greater than 300s for most targets these days. The 600+ subs are for when I use my Ha filter and can go up to 30min subs then.

Try 300s to start with, your setup that should capture something but may not really see it until processing time. Has APT got a stretch feature? Been a while since I looked at it.

Look forward to the results of the next session, I am on Astronomyshed more than SGL, normally in chat specially if imaging.

Cheers

Hiya

Ok - I'll stick to 300s next time and keep my fingers crossed! I tried my Ha for the first time last night too - just a few 1200s subs. Still seemed quite dim but I've not looked properly yet. Yes, APT has a histogram which allows you to set dark and light levels just for the display - it's very useful! I think you can see it on the screen capture I posted though it was at the default, unstretched setting to show the native sub.

Cheers

Louise

[Thalestris24]

Hi Louise,

Drop the sub length to 300s and go for a lot of subs if possible to overcome the noise. M33 is not at all easy due to its low surface brightness and I have found it to be quite a noisy beast too.

I know the problem you have with your window and the LP so you may have to do this over a few nights if this " summer " weather permits. I believe there is another dead hurricane leftover that is heading our way for the weekend from the Atlantic. I did a test of my new scope and M33 last night and I could have gone for 900 ~ 1200s subs but I did 600s and it sort of worked reasonably well but your LP maybe different to mine.

Regards,

A.G

Hiya

Will do! I only get about 45-60 mins for any one object and I'm not sure how long M33 will be accessible to me. But I'll keep trying and there's always next year!

What's your new scope?

There may be a short imaging window tonight but I won't hold my breath!

Cheers

Louise

[lensman57]

Hiya

Will do! I only get about 45-60 mins for any one object and I'm not sure how long M33 will be accessible to me. But I'll keep trying and there's always next year!

What's your new scope?

There may be a short imaging window tonight but I won't hold my breath!

Cheers

Louise

Hi Louise,

Tonight is a loss again in rainy Manchester. I ordered a WO Star 71 Ian King in July and I got it just before I went on Holiday so last night was the first light for this little beauty.

A.G

[Thalestris24]

Nice scope! Better for most nebs than my 150pds! I keep thinking about getting a frac now I have a second mount (AVX). Then again, I need a filter wheel, a second guide cam and.. and.. and I need to win the lottery!

Louise