Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Can't find planetaries NGC 2392 and NGC 3242

dso observing planetarium software
  • Please log in to reply
12 replies to this topic

#1 FredOz

FredOz

    Sputnik

  • -----
  • topic starter
  • Posts: 37
  • Joined: 26 Jan 2020
  • Loc: Prescott, AZ

Posted 21 May 2020 - 09:54 PM

Last night I looked unsuccessfully for NGC 2392 (Clown Face nebula) and NGC 3242 (Ghost of Jupiter nebula) with my 150 mm f/8 Newtonian under an estimated Bortle level 3 sky.  I believe I had the right locations based on Turn Left at Orion and Stellerium but I saw no hint of nebulousity at either low-power (32 mm, 38X) or medium (15 mm, 80X).  I had a higher power eyepiece (9 mm, 133X) fitted with an OIII filter but didn't use it because I could not see the planetaries.  I also have a 5 mm, 240X that has been disappointing and a 2X Barlow but did not try them.

 

I just read a thread from 2017 that suggests higher power: 

But what good is high power if I cannot find the object?

 

Below is a chart I made using Stellerium and PowerPoint.

Attached Thumbnails

  • Nebula.png


#2 Thomas Marshall

Thomas Marshall

    Viking 1

  • *****
  • Posts: 588
  • Joined: 24 Feb 2015
  • Loc: Spring Valley AZ.

Posted 21 May 2020 - 10:25 PM

I can't say about the "clown nebula", but the 'Ghost of Jupiter' is pretty easy, and you have good skies. My guess is you mistook it for a Fuzzy Star, and didn't dial in on it. 



#3 Cames

Cames

    Viking 1

  • -----
  • Posts: 947
  • Joined: 04 Aug 2008

Posted 21 May 2020 - 11:20 PM

I agree with Thomas. Magnification will reveal the candidates for you.  Especially when seeing isn't the best, one can mistake the planetary for a star at low magnification.  Make sure that your finder is precisely coordinated with the optical axis of the SkyWatcher.  Both are nice dense planetaries, roughly the diameter of planet Jupiter and will be rewarding once you reveal them. NGC 2392 you may actually see the Eskimo's parka at high power.  Good hunting. I predict you will succeed next time out although it is getting late in the season for 2392.

------------

C

 

 



#4 Keith Rivich

Keith Rivich

    Vanguard

  • *****
  • Posts: 2,134
  • Joined: 17 Jun 2011
  • Loc: Cypress, Tx

Posted 22 May 2020 - 04:57 PM

Both of these are pretty easy to see in my 80mm finder at 12x. They look like fat stars. The Eskimo is right next to a similarly bright star and one can readily see the difference in appearance. I'm with Thomas...you were probably on them but did not recognize them as planetaries. 


Edited by Keith Rivich, 22 May 2020 - 04:58 PM.

  • havasman likes this

#5 havasman

havasman

    Voyager 1

  • ****-
  • Posts: 10,801
  • Joined: 04 Aug 2013
  • Loc: Dallas, Texas

Posted 22 May 2020 - 05:33 PM

NGC2392 is well placed for observing from @ early January to maybe mid-April but now by sundown is quite low in the west and even lower by the time it's dark. NGC3242 is somewhat better placed but is moving away from the meridian at sundown.

 

You may like to try NGC4361 in Corvus. It is a bit dimmer than either of the others and about twice as large in total but it sits very near meridian at sundown. Very high surface brightness NGC6210 in Hercules is a good option late these nights and will become well placed at sundown pretty soon.


  • j.gardavsky likes this

#6 Dave Mitsky

Dave Mitsky

    ISS

  • *****
  • Moderators
  • Posts: 90,411
  • Joined: 08 Apr 2002
  • Loc: PA, USA, Planet Earth

Posted 22 May 2020 - 05:58 PM

NGC 6543 in Draco is another possible target.


  • havasman and j.gardavsky like this

#7 Love Cowboy

Love Cowboy

    Viking 1

  • -----
  • Posts: 968
  • Joined: 05 May 2014
  • Loc: Houston, TX USA

Posted 22 May 2020 - 06:41 PM

As others have said, most bright PN's are quite small. If you're new to this, you could easily mistake them for stars if you're sweeping the area at high speed. They're also super bright. You're not going to be seeing a large fuzzy glow like a galaxy; it will be a small disk, much like a planet (that's where the name for the class of objects came from). Slow down and examine. See what looks to be a bit bigger than a star. THEN crank up the power to verify your identification and examine the details.


Sent from my SM-G930P using Tapatalk
  • kfiscus likes this

#8 Sketcher

Sketcher

    Apollo

  • *****
  • Posts: 1,303
  • Joined: 29 Jun 2017
  • Loc: Under Earth's Sky

Posted 22 May 2020 - 06:44 PM

Fine tune your pointing, then up the magnification.

 

If one knows what to expect and look for, these planetaries can be spotted and recognized at relatively low magnifications.  But until one knows, they can be mistaken for stars unless higher magnifications are used.

 

For an idea of scale, M57 is about 230" in size.  Ghost of Jupiter is about 25" in size.  Eskimo Nebula is about 48" in size.

 

Relatively speaking, M57 is a monster!

 

Looking at Ghost of Jupiter at 80x is like looking at M57 at about 9x -- pretty small.  The Eskimo at 80x would be similar in size to M57 at about 16x.

 

Fine tune your pointing, then up the magnification!

 

And of course, everything is better when higher in one's sky.  I generally focus on nebulae that are either high in my sky or (me being in the northern hemisphere) near my south meridian (as high as they're going to get for me.)


  • payner, kfiscus, havasman and 1 other like this

#9 FredOz

FredOz

    Sputnik

  • -----
  • topic starter
  • Posts: 37
  • Joined: 26 Jan 2020
  • Loc: Prescott, AZ

Posted 23 May 2020 - 12:00 AM

I can't say about the "clown nebula", but the 'Ghost of Jupiter' is pretty easy, and you have good skies. My guess is you mistook it for a Fuzzy Star, and didn't dial in on it. 

Thanks to all for the advice.  I did see both nebulae tonight from my Bortle 5 front yard despite neighbors bright mail-box lights.  I could not detect either at low power, 38X but did notice a fuzzy star appearance at medium power, 80X) and could definitely see them in my higher power eyepiece, 133X.  The O-III filter (Svbony UHC) did not seem to help much.

 

I tried a 2X Barlow on the Clown, thus giving 266X and that made it bigger but harder to keep in the field of view.  I did not try the Barlow on the Ghost because there were no reasonably-bright stars nearby to use to focus.


  • havasman and Thomas Marshall like this

#10 chrysalis

chrysalis

    ISS

  • *****
  • Posts: 21,636
  • Joined: 10 Aug 2013
  • Loc: North Central NC

Posted 23 May 2020 - 03:35 AM

Great that you found both, good advice from all.

 

The two best ways to distinguish most high SB PNs in my experience are "fuzzy" star and distinct cyan color. Fuzzy star perception just takes some experience to develop. I experienced it's slow evolution as a new impression that while all the other stars in the field were "pinpoints", this one "star" was bloated / unfocused / swollen. Cyan color kind of speaks for itself.

 

By the way, the color criterion doesn't apply to IC418 ... ;)



#11 Andrekp

Andrekp

    Mariner 2

  • -----
  • Posts: 210
  • Joined: 14 Apr 2020

Posted 23 May 2020 - 10:39 AM

Try moving your filter in and out of view at the eyepiece as you are looking.  The stars will darken, the planetary mostly wont.  It helps to narrow down which is which before you are sure.



#12 IVM

IVM

    Surveyor 1

  • -----
  • Posts: 1,606
  • Joined: 07 Jan 2008

Posted 23 May 2020 - 04:29 PM

It's like that with all small objects. Find the location based on the star chart, then switch to high power to see the object. You probably saw them, but they looked like stars.



#13 Feidb

Feidb

    Mercury-Atlas

  • -----
  • Posts: 2,926
  • Joined: 09 Oct 2009
  • Loc: Nevada

Posted 25 May 2020 - 08:23 PM

I've seen NGC-2392 multiple times and it's been a fuzzy round ball with a star in the middle.

 

NGC-3242 has a slightly bluish tint, is oval shaped, flaking at the edges and at least one time, kind of reminded me of the Blue Snowball. I've also seen it multiple times.

 

Out of all those observations, I only used the O-III one time and that was on 2392 and I wasn't impressed with the improvement. The nebulae looked best unfiltered. Magnifications ranged from 70X up to 480X.




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics





Also tagged with one or more of these keywords: dso, observing, planetarium software



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics