Testing V0.11 on Leo

[Paul81]

A nice crisp and very cold clear night presented a good chance to test V0.11 out in the field and try out some of the new features.

It should be noted that the stacking statistics (e.g. 8 x 30s median) are now added automatically by LL during export. Much easier than typing it in with cold fingers in the dark (my old macbook I use for capture doesn't have a keyboard backlight).

Firstly, NGC 2261 or Hubble's Variable Nebula in Monoceros. This was actually my second target, the first being the Rosette Nebula but this was way too big so I didn't bother saving anything. NGC 2261 is an emission and reflection nebula which envelopes the variable star R Monocerotis. As the star that powers the nebula is variable, the nebula itself varies in brightness with the star. NGC 2261 is around 2.5KLY distant. The new x^0.25 scaling mode worked best for this object which is actually quite bright.

Next over to the main focus of the session – galaxies in Leo.

M95 and M96 are a pair of spiral galaxies which are part of the Leo I group. M95 is around 36 MLY distant, and was one of the key galaxies (in addition to M96) surveyed by HST to observe and determine the distance to Cepheid variables in the galaxy and ultimately the Hubble constant. M96 is around 41 MLY distant. Arcsinh display scaling worked very well when observing these galaxies, in combination with sum stacking. Another new feature is the ability to set a definitive peak histogram value. This means no more chasing sum stacking – the latest sum stacked image will be shifted to the same peak value each update. Combined with non-linear scaling means you can set your display parameters up and then sit back and watch the detail grow as each new exposure comes in and is stacked. I also found I could use pretty much the same settings for most of the galaxy observations in this post, bar some minor tweaks. For me, this new feature worked really well.

In close proximity (in terms of sky location) is M105, a giant elliptical galaxy (top). Also in the frame are NGC 3384 (left) and NGC 3389 (bottom). M105 is a member of the Leo I group. NGC 3384 is also thought to be a member. NGC 3389 is a background object as it is moving away from us much faster than any of the other galaxies in the group. M105 is 32 MLY distant. Pretty much the same display settings were used when observing this object. The non-linear scaling really helps to bring out detail in the galaxies without washing the cores out too much, although in the case of M105 as it is an elliptical galaxy it always tends to look like a big blob – even in long exposure images.

Carrying on the theme, next up were M65 and M66, two of the three galaxies in the Leo Triplet. These galaxies are also part of the Leo I group. M65 and M66 are 35 MLY distant, and show signs of deformation (and are part of the ARP catalogue of peculiar galaxies) from interactions. Again the new display scaling really helped bring out detail in the galaxies without bloating out the core, and some nice dust lanes are visible in the EAA images.

NGC 3628 is also part of this mini group with M65 and M66, but at this point I was frozen solid so will make a start with this one next time! (I also wanted to take some video of Jupiter but couldn't face the cold any longer).

Overall a good test of the new code. I think it is pretty much functionally complete now (for this release anyway). I didn't encounter any major bugs, and the main modification I want to make based on this session is change the scaling of the slider controls depending on the display scaling mode, as the full range is 'too much' for some modes. Currently I am in the process of optimising the new code, as it is a touch slow at the moment (straight C++ code – I am vectorising the code to yield 4x speed-up).

[Martin Meredith]

I did a double take when you mentioned Leo. Kudos for beginning galaxy season early!

You're getting some great detail out of those galaxies, esp. M66 and the barred structure of M95 is really clear. Those nonlinear modes are obviously working really well.

I like the idea of not chasing the sum stack too as that's the main reason I've tended to use mean or median most of the time.

We're in a for a run of clear nights (albeit moonlit and with the temp below freezing) so if you need any beta testing….

cheers

Martin

[Mac4Lyfe]

Awesome stuff Paul.

[HiloDon]

Hi Paul,

Really great results! I second everything Martin said.

Thanks for working so diligently on LL and making EAA so much fun.

Have a great New Year!

Don

[Paul81]

Thank you all, and I hope everyone has a great New Year! 

[nytecam]

Very impressive Paul via LL v0.11 - especially liked Hubble's Var Neb - keep up the excellent work

[f15p5]

NGC 2261, one of my favorites! Thanks for the images, and all your hard work on LL. Happy New year!

Cheers,

Richard

[Paul81]

Hi all,

Just a quick update on V0.11. Beta-testing has been very encouraging with some terrific results being achieved with the new display processing controls so I am pretty happy. I have also optimised a fair amount of the code, so providing nothing comes up this week I will release the new version on the forum ready for next weekend (fingers crossed for clear skies).

I'll also try to work on some tutorial videos this week to coincide with the new release.

Paul

[f15p5]

Hi Paul,

Sounds great! Can't wait to try it out, from the video it looks like it will be easier and have finer controls. Sure do appreciate all your hard work.

Thanks,

Richard