AKB

The start of another month, and another Zoom virtual observing session for the local astro club (Abingdon.)  This was the third go at running it this month, the previous Monday and Tuesday being complete washouts.  There was much discussion as to whether the rain and clouds would clear in time to start at 20:00, and for some of us, it did.  Several other members had widefield scopes with colour cameras and gave us some great views of some favourite nebulas:  Monkey Head, Jellyfish, California, Wizard, ...  I stuck with the monochrome Hyperstar/Ultrastar as, for me, it works very well in this scenario.  For simplicity, and to space out my contributions, I stuck to 20 x 30 second images.

• A couple of nebulas – to show that they can look good in mono (although, to be fair, they're great in colour.)

1. NGC 1333, the 'Embryo' reflection nebula, in the western part of the Perseus molecular cloud with very active star formation
2. NGC 1579, the 'Northern Triffid', actually an H-II region, again with star formation

• IC 289 – planetary nebula in Cassiopeia, with some features clearly visible.  Also an apparent pair of galaxies on the RHS of the shot, along with a marvellous linear chain of stars below.
• NGC 2419 – the 'Intergalactic Wanderer', actually believed to orbit the Milky Way at a distance of ~300,000 LY, taking 3 billion years to do so

Documented elsewhere from this evening's haul are:

• Arp 331 – https://stargazerslounge.com/topic/351721-arp-galaxies/page/6/#comment-4177351
• Comets 29P and 2019L3 – https://stargazerslounge.com/topic/384395-three-comets/#comment-4177330
• Globular cluster Palomar 2 – https://stargazerslounge.com/topic/387223-auriga-–-palomar-2/#comment-4177323

After the rain, the transparency seemed rather good.  It was a great night.

Tony

Arp 331, including NGC 380 and friends – too many to count, really.

Also in there, I've labelled PGC1999169 and PGC2001155 about 1,600 Mly away and Mag 18.

Also, a quasar there too.

Tony

Another opportunity to view two of these last night:

• 29P – in Aurega (I think) with an L-shaped flare perhaps visible from the nucleus
• 2019L3 – in Lynx, very close to the 'Intergalactic Wanderer'  NGC 241

Tony

During last night's virtual observing session(1-Dec-2021) for the local astro club (Abingdon) I was challenged to get the Palomar 2 globular, which I did...

Below is a widefield shot from the usual Hyperstar/Ultrastar combination:

This was discovered in the National Geographic Society – Palomar Observatory Sky Survey (POSS-I) started in 1948 and finished in 1958, using the 48" Oschin Schmidt telescope.  The survey was repeated in the 1980's and 1990's (POSS-II) using better films and an upgraded telescope.  The results are available here:

https://archive.stsci.edu/cgi-bin/dss_form?target=palomar+2&resolver=SIMBAD

I was keen to see how my 10-minute integration with a 9.25" Schmidt (actually stopped down to 8.6") would compare.  Here it is, as a negative, with a similar field of view to the red plate  images available from POSS-I and POSS-II, which follow (inverted, flipped, and grey-levels adjusted.)

How technology has moved on! (I'm also not at the top of a mountain.)

Tony

PS: Interesting to note that there are a couple of stars to the right of the cluster which appear in POSS-I and not POSS-II or mine.  Not sure what these might be?

I’ve had these symptoms a while ago.  Quite frustrating… it seemed to be to do with the driver software losing calibration.  It eventually settled down, and I can’t really remember doing anything special, although you might choose to change the USB cable, just to be on the safe side. 

Hoping that recalibrating will sort thing for you.

Tony

41 minutes ago, GalaxyGael said:

Quite a bit of atmospheric dispersion evident with 'french flag' stars

Have you tried separating and aligning the RGB components with each other, as an early processing step?

Thanks for that… just trying to learn from the experts.  My processing skills are almost non-existent, which is why I do EEVA most of the time!

I definitely need some guidance with respect to my use of sharpening and the various filters available.  I suppose it depends on what result you're really trying to obtain., and I really like thegentle look that you get, somehow.  I presume that doing something like this to it would be going over the top...?

Tony

Looks absolutely great to me!

Did you do any sharpening on that?  Interested to see if there's yet more detail there as signal-to-noise looks very good.

Tony

30 minutes ago, Mike JW said:

don't forget there are the different threads in the forum to keep targets together such as Arps, Hicksons........

Thanks for that, Mike.  Trouble is, there’s not inconsiderable overlap between a fair number of classifications, so where to post?!

One of the joyous things about EEVA is that a bright moonlit night need not deter you from observing.

Nov 21, 94% moon, slightly hazy, windy, early evening, and not very good transparency... not ideal conditions, one would think...

...so for no particularly good reason, other than it wasn't facing directly at the moon, I fancied that I would take a look at NGC 66xx galaxies in Draco.  The Jocular observing list, used as a planning tool, is ideal for this sort of spur of the moment whimsy:  "I think I'll rank them by size and see how far I can go, and whilst I'm at it, I'll limit my choice to those above 40 degrees of elevation to make sure I get a clear shot at things."

• NGC 6643 – nice spiral structure visible. Nearby galaxies PGC 2763587 and 2764674 are mag 17.6 and 17.4 repectively.
• NGC 6690 – the bright star is mag 7.7 and PGC 2736579 is 17.6
• NGC 6654  – a lenticular galaxy with an interesting skew between the axis of the brighter central region and the weaker outer one.  PGC 61821 is mag 16.7, and outside this view, but just on the edge of the full frame is the star Alahakan at mag 3.5!
• NGC 6651 – another spiral with nearby star (unlabelled here) HD 171044 of mag 7.3 and  PGC 97551 at mag 18.2

One of the slight challenges is the number of very bright stars nearby, but my recent fettling of the C9.25 Hyperstar arrangement (now slightly stopped down to F2.5 and with the USB cable neatly curved over the corrector plate) has reduced spikes and flaring to something close to the minimum possible ( I believe and hope.)

Having seen the above, it's time for my evening meal, so what shall I point to nearby that might be fun to let run?  How about the Fireworks galaxy?  The image below is just 5 minutes worth of the 45 minutes total that it took, and, frankly, I couldn't tell the difference between the images... due, I suppose, to the moon's glow limiting the achievable contrast.    So this is NGC 6946 and Arp 29, and in doing a little research whilst writing up this observation, I checked my copy of the The Arp Atlas of Perculiar Galaxies where it's described as "Spiral with one heavy arm."  More than that, though, I was shocked and delighted in equal measure to discover that my image compares remarkably favourably with the image there – one of Robert Gendler's taken with a 12.5" RC and 300 minutes of exposure!

Just to make a point, I then gave it a whole 10 minutes on the Elephant's Trunk, Sh 2-131, and was amazed at what came out (this is with no filters at all.)

All this before 8.30 PM, since I had to go and do the washing up.

Hope you enjoy this as much as I did (the EEVA, not the washing up.)

Tony

I’ve always had really great service from  W&W Astro, here 

https://dewheater.com

24 minutes ago, 69boss302 said:

You sure made a substantial move to the UK!!!

No, no... it was a substantial move from the UK.  CT was lovely, certainly nicer than TX where I was for 5 years!

1 hour ago, 69boss302 said:

Care to share your flow, or your apps used?

I’m certainly no expert, and I happen to use PixInsight, but there are plenty of others to choose from.  The workflow I used was extremely simple, just to give an impression of what’s there.  Your basic acquisition seems OK, apart from the back focus to your field flattener, but you know that already.

• colour calibration
• background subtraction
• mask and stretch (including saturation)

Mono with filters is mostly just extra hassle to combine them in the first place, so almost everything you see about processing in general should be just as applicable.  My biggest concern, and opportunity for improvement, would be in the correct acquisition and application of flats.

Having said that, for someone starting out, you seem to be doing exceptionally well (and having a good camera does help.)

Tony

PS: I used to live in Brookfield CT, near Danbury, and worked in Ridgefield.  Beautiful place, especially this time of year.

1 hour ago, 69boss302 said:

Would love to see what you guys can do with this

Just very quickly passing over the data (which has pretty severe background and vignetting, so I don't think flats have worked) ...

Tony

@furrysocks

I came across this paper independently recently.

Thought I would prototype it in Matlab (my tool of choice for playing with signal processing.)

Any further experience of this? Interested as a "black box" in EAA processing.

Or has anyone else given this a go?

Tony

Absolutely love it.  For me the size is right (not too many pixels.)  Its only slight downside is amp glow, but that calibrates out just fine with darks.

Check out my gallery images using it with an Esprit 120ED or a 9.25" Hyperstar.

Welcome back, from someone else near Oxford!

200P still talked about and used here, I think you'll find.

For a planetary camera, you'll be amazed by some of the newer CMOS cameras, which can also do the business for DSO.

I'm sure several people with more expertise will be along with advice shortly.

Abingdon has a thriving astro club if you're interested in meeting with others – and we're actually doing Zoom-based observing evenings for a while (once a month.)

Welcome again,

Tony

Here's one target on the original list that I forgot to post...

...actually three edge-on (or nearly so) galaxies in Andromeda:

• NGC 891
• NGC 898
• PGC2192261

9 minutes ago, Mike JW said:

I have Aladin downloaded onto my laptop.

Oooh.  Useful.  Just given that a try.

I'm thinking:

2MASX J03022035+4617511

just from the look of it...

http://simbad.u-strasbg.fr/simbad/sim-id?Ident=2MASX+J03022035%2B4617511&

50 minutes ago, Mike JW said:

WISEA J030220.32+461751.4  I think.

Mike

Oh, thanks.  Does that mean I'm missing a catalogue in Jocular, or something?

How did you do that?

12 hours ago, Martin Meredith said:

I particularly like NGC 1169 as I have a soft spot for galaxies in the midst of a rich star field.

...speaking of which, do you have any idea what the fuzzy at about 4 o-clock near the edge of this capture might be?

Plate solving with the catalogues that I have loaded does not label it...

I can't find it in Pretty Deep Maps, either...

Essentially correct.  You don't need to synthesize an L file – Jocular will do that internally itself.

You can, no doubt, use the Jocular library for debayering, but the simplest approach is to use "super-pixels", which essentially use a 4x4 matrix (typically of RGGB) to generate a single (RGB colour) pixel, thus binning the image x2 at the same time.  This is quite effective for modern CMOS OSC which tend to have small pixels and too many of them for Jocular to be entirely comfortable (in terms of operating speed.)

1 hour ago, Mike JW said:

Good to see you are back in action.

Thanks, Mike.  Nice to have the darkness back and the scope ready (but nothing going today!)

1 hour ago, Mike JW said:

NGC 70 is the spiral and NGC 71 and  68 are presumably the E and E like galaxies but is there any perturbing on the go?

Hard to say.  I've zoomed in a bit, but it's a bit noisy and you can see from the square stars that the Ultrastar's big pixels (6.45 microns) under-sample a bit (which I suppose means that my focus and collimation is actually not too bad.)

2 hours ago, RobertI said:

Please do post some of your other images, we EAA’ers don’t care about such things as coma and out of focus stars!

Well, since you ask...

• NGC 1055 – two shots here, one zoomed in, the other widefield to show M77, since together they are a binary system.  Discovered by Willam Herschel, it look somewhat lop-sided, allegedly because one of its spiral arms occludes the upper part of the central bulge.
• NGC 7479 – Another of WH's discoveries, this is a Seyfert galaxy (having strong emission line spectra from its nucleus.)
• NGC 1169 – barred spiral, and yet another WH discovery
• NGC 925 – (The Amatha galaxy) a barred spiral, and  a member of the NGC 1023 group.