Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

stargazine_ep2_banner.thumb.jpg.e37c929f88100393e885b7befec4c749.jpg

jetstream

Faint galaxies/24"

Recommended Posts

Can I bore everyone with another report?

The sky was good with structure in the MW and with M8 etc easily naked eye down south. I wanted to pursue Draco after seeing a nice galaxy near the Catseye nebula.  This scope seems to do well so far on galaxies so I put a few into the Sky Commander to see what I could get.

First a triple set consisting of NGC 6419 @ 15.5 mag, .95 arcmin, NGC 6420 15.5 mag, .45 arcmin and NGC 6422 15.1 mag .56 arc min. All three were bagged with NGC 6420 flicking in and out of averted vision. I was using the Nikon HW 14mm, good for this but not that good. Next time an ortho comes out, these galaxies sit in a triangle of 3 mag 8 stars for reference.

I had a failure on the NGC 6456 group with it being 15.7 mag and .34 arc min. At least I'm defining the limits so to speak.

Over to a great planetary- the Magic Carpet nebula- NGC 7027- what color! a very bright green in the 14mm HW with a hint of asymmetry at this lowish mag- next time more power goes on it.Man is it bright,small but bright. After galaxy observing a bit more relaxed sky cruising is nice so over to M24, a special favorite and what do you know? B93 and B92, 2 beautiful dark nebs stood in stark contrast to all those stars.

One last view...I picked M101 to finish the night- hey- who put all those faint galaxies near it?!:grin: I must have chosen not to see them before lol! Seriously though NGC 5485 @ 12.2 mag 1.6 arc min very easy and the faint NGC 5484 15.6 mag .34 arc min bounced in and out of averted with NGC 5486 held in direct at 14 mag and ,49 arcmin. NGC 5473 and NGC 5477 were there too along with the always bright NGC 5474.

So anyway, that was my night, time for bed. The scope used was the 24" with 20mm lunt HDC and the Nikon 17/14mm HW. Filters were the Lumicon UHC and OIII.

  • Like 12
  • Thanks 1

Share this post


Link to post
Share on other sites

Very interesting report with your new big gun Gerry :smiley:

From my back yard my 12 inch gets me down to mag 14.7 (thats the best so far) so it sounds like you are getting a full mag fainter with double the aperture and your darker-than-mine skies. And I suspect there is a wee bit more to come from your 24 incher !

 

  • Like 2

Share this post


Link to post
Share on other sites

Great report, Gerry! 

I also think that the cannon can go deeper. Any plan for Docter+VIP? :D

  • Like 1

Share this post


Link to post
Share on other sites

Yes, the Docter and orthos will be used as well as the 10mm BCO which is a good copy. I was out in the sun yesterday and had issues dark adapting- it took me much longer than normal. These computer screens don't help and neither does the Sky Commander 's green screen...

The Nikon HW/barlow at 14mm is acceptable but not optimum and the 10mm BCO will go a hair deeper than the Docter as tested in the 15" .  One thing is for certain, the size of the galaxy impacts its viewability and much higher mag is needed, where the f4 allows for a nice increase here. I have an excellent copy of the 7mm KK ortho for 357x. This one got me the central star in the ring nicely in the 15".

As far as magnitude limits what are the thoughts about point sources vs extended objects vs limiting magnitude?

Moore has a more conservative rating for point sources as shown in the chart.

"

Limiting Magnitude

Aperture (inches)
Aperture (mm)
Limiting Magnitude
(method 1)
Limiting Magnitude
(method 2)
1/4 6 7.5 6.3
.31 8 8.2 6.9
2 50.8 12.2 11.0
3 76.2 13.1 11.8
4 101.6 13.7 12.5
5 127.0 14.2 12.9
6 152.4 14.6 13.3
8 203.2 15.2 14.0
10 254.0 15.7 14.5
11 279.4 15.9 14.7
12 304.8 16.1 14.8
14 355.6 16.4 15.2
16 406.4 16.7 15.5
17 431.8 16.8 15.6
18 457.2 17.0 15.7
20 508.0 17.2 16.0
22 558.8 17.4 16.2
24 609.6 17.6 16.4
30 762.0 18.1 16.8
32 812.8 18.2 17.0
Edited by jetstream
  • Like 4

Share this post


Link to post
Share on other sites

Keep them coming Gerry! Great to have you posting regularly again.

I'm sure there is plenty more to come. I wonder if it is worth using some neutral density film over the Skycommander display if it is too bright?

  • Like 1

Share this post


Link to post
Share on other sites
1 minute ago, Stu said:

Keep them coming Gerry! Great to have you posting regularly again.

I'm sure there is plenty more to come. I wonder if it is worth using some neutral density film over the Skycommander display if it is too bright?

Thanks Stu, the weather is finally co operating.

I must do something, including shutting it off if needed- maybe an orange film over it to turn red? Another no no for me is the computer screen with its polarized light- this wrecks my eyes for a very long time, as well as the LED TV.

 

  • Like 1

Share this post


Link to post
Share on other sites
7 minutes ago, jetstream said:

Thanks Stu, the weather is finally co operating.

I must do something, including shutting it off if needed- maybe an orange film over it to turn red? Another no no for me is the computer screen with its polarized light- this wrecks my eyes for a very long time, as well as the LED TV.

 

That's good news.

A bit of experimenting needed perhaps to see what works best. I assume you have dimmed it as far as it goes in the settings?

Share this post


Link to post
Share on other sites

Lovely read Gerry....I feel the ap fever is upon me!

  • Like 1

Share this post


Link to post
Share on other sites
15 minutes ago, Stu said:

That's good news.

A bit of experimenting needed perhaps to see what works best. I assume you have dimmed it as far as it goes in the settings?

yes, its on the lowest setting and I love this thing already. Even with all my ducks in a row I'm not so sure I'll exceed 16mag on an extended object by much... with the 15" I don't think I exceeded Moores magnitude in the chart on an extended object.

Share this post


Link to post
Share on other sites
6 minutes ago, estwing said:

Lovely read Gerry....I feel the ap fever is upon me!

Thanks Calvin!

Just curious for reference, how faint of galaxies can you guys go on dark sites?  Has anyone gone over 16mag on one?

Share this post


Link to post
Share on other sites

15 occasionally...Mapstar has had success with higsons 55.

  • Like 2

Share this post


Link to post
Share on other sites
10 minutes ago, estwing said:

15 occasionally...Mapstar has had success with higsons 55.

Thanks so much Calvin, the voice of experience means a lot. I just looked up Hickson on Vogels site- I can see where magnitudes get confusing- Vogel lists blue and red magnitudes and judging from the red I can see an opportunity for 4 of them-"a" and"b" should be do able here with luck, maybe more. Simbad lists UGC 6514 (Hickson 55) as 15.2 mag-maybe for the object as a whole.

If you guys have any suggestions for me pass them on will you? Thanks, Gerry

Share this post


Link to post
Share on other sites

One of the best and challenging books for big dob owners is the peculiar galaxies book available from FLO. very interesting articles and gives descriptions from observers using 18,20,22,24 even 26 and bigger scopes.

I highly recommend it Gerry.

  • Like 1
  • Thanks 1

Share this post


Link to post
Share on other sites

Yes mags do vary in different books,websites and even on sky safari!

  • Like 1

Share this post


Link to post
Share on other sites

You'll be in PGC territorys along with PALs!!!

  • Like 1

Share this post


Link to post
Share on other sites
2 hours ago, estwing said:

One of the best and challenging books for big dob owners is the peculiar galaxies book available from FLO. very interesting articles and gives descriptions from observers using 18,20,22,24 even 26 and bigger scopes.

I highly recommend it Gerry.

Thanks Calvin, I'm going to get it. Tonight looks very good! Possibly better than the last couple of night, we'll see. Maybe I'll dust off the 10mm BCO and try Hickson 55 its nice and high.

Share this post


Link to post
Share on other sites

Fantastic report, Gerry. Your influence on me always shows through when I reach for the Orthos on fainter targets! 

The Interstellarum Deep Sky Guide is a great book and has a definite big scope bias. Lots of sketches of targets at very high power in big scopes. Examples of the cat’s eye and Hickson 55 below.

274019BF-8EC9-4476-AAA6-40E71B6CB64A.thumb.jpeg.12acc4a1a4a2ecbb6ce148d1df5cc86d.jpeg

98981268-79CE-4423-A3A1-9E4A96C99E8A.thumb.jpeg.067f9d3f77741ea7703f740d3c0c0fe7.jpeg

F1B1CF26-CA86-441E-A8C7-AA06CDCC2954.thumb.jpeg.ca0de1477ac786317191a7e4b7826247.jpeg

8530A9E7-AE95-486C-BE6F-FAE5D9163B92.thumb.jpeg.81f0eb4c1cb475fae5bc3ea78060c50e.jpeg

Edited by Littleguy80
  • Like 1
  • Thanks 1

Share this post


Link to post
Share on other sites

Yeah....those D and E take some teasing 😳

  • Like 1

Share this post


Link to post
Share on other sites
7 hours ago, Littleguy80 said:

The Interstellarum Deep Sky Guide

Thanks Neil, I need resources such as this- I'm a bit lacking in the info dept.. had a great night last night and the ortho worked! M57 central star easy with the 10mm BCO at 249x, among other things. Hickson 55 was behind the trees though unfortunately.

  • Like 2

Share this post


Link to post
Share on other sites
7 hours ago, Littleguy80 said:

The Interstellarum Deep Sky Guide

Where did you buy it Neil, it seems very expensive here...

Share this post


Link to post
Share on other sites

I got urano off FLO good details and the field guide is full of information. 

20190629_165916.jpg

  • Like 2

Share this post


Link to post
Share on other sites

These are from the peculiar atlas

20190629_170224.jpg

  • Like 1

Share this post


Link to post
Share on other sites
1 minute ago, estwing said:

20190629_165907.jpg

Thanks Calv- what red torch do you guys use at night?

Share this post


Link to post
Share on other sites

Great notes at the bottom also..

20190629_170233.jpg

  • Like 2

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.