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

Challenge Objects: In Aquila/Cygnus

  • Please log in to reply
6 replies to this topic

#1 RLK1

RLK1

    Viking 1

  • -----
  • topic starter
  • Posts: 519
  • Joined: 19 Apr 2020

Posted 10 August 2020 - 10:20 PM

Using the Observer's Guide, I've noted several planetaries that have been described as challenge objects for 16"/18"in Aquila and Cygnus. Although I could penetrate to about magnitude 13.5 in front of my light polluted home last night with very good transparency and excellent seeing, the following planetaries are around 13.5 magnitude or greater and some appear stellar in surrounding star fields. 

First up: PK 85 +4.1 Abell 71 in Cygnus.  At magnitude 14.5, it's said to appear as a very faint, tenuous 2' disc with milky way stars superimposed on it:

https://in-the-sky.o...php?id=Abell_71

Next in Cygnus: PK77 + 14.1 Abell 61.  At magnitude 13.5, it's said to be responsive to an O111 filter and the Guide notes it to be an extremely faint and diffuse 2' diameter disc:

https://in-the-sky.o...php?id=Abell_61

Also in Cygnus: PK 81 -14.1 Abell 78: At magnitude 13.4, it's 1.5' disc, although responsive to an 0111 filter, sits between two 7th magnitude stars and their glare interferes with it:

http://www.visualdee...g/msg01154.html

Moving onto Aquila, PK 40 - 0.1 Abell 53: At magnitude 15.5, it's 30" disc is said to be extremely faint although responsive to an 0111 filter:

https://in-the-sky.o...php?id=Abell_53

PK 47 - 4.1 Abell 62:  At magnitude 14.8 is fairly large but is situated in a rich star field:

https://in-the-sky.o...php?id=Abell_62

PK 51 - 3.1: At magnitude 13.7, it's said to require "blinking" with an 0111 filter in order to be visualized at powers of 300X or more:

http://martingermano.com/PK51-3.1.htm

Well, I have a bit of a plate waiting for me at my favorite dark sky site...

PS Seeing was so good last night that I was able to use a 3.2mm x cel eyepiece, the shortest focal length eyepiece in my collection, in my 16" f4.5 dob on Saturn and Jupiter...talk about "big planets"!


  • Dave Mitsky, Ptarmigan and Allan Wade like this

#2 Allan Wade

Allan Wade

    Aurora

  • *****
  • Posts: 4,738
  • Joined: 27 Jan 2013
  • Loc: Newcastle, Australia

Posted 10 August 2020 - 10:49 PM

Planetaries are amongst my favourites. They can hide in a star field by pretending to be a star, or hide in plain site by blowing themselves up to a huge scale.


  • KidOrion likes this

#3 andreww71

andreww71

    Ranger 4

  • *****
  • Posts: 307
  • Joined: 07 Jul 2014
  • Loc: NE Ohio

Posted 11 August 2020 - 08:14 PM

I’ve been slowly picking away at the Abell planetary catalog since the mid 1990’s. I first started with an 18” F/4.5 scope, and then moved up to a 22” F/5. After a long hiatus I reentered the hobby and have continued to pick away at these often exceedingly faint objects, most recently with a 22” F/4.16. I’ve read reports of people seeing most of the catalog with similar sized scopes but they are observing under much darker skies than I am.

 

My notes for the objects you list:

 

Abell 71 – 18” / 73x / OIII Filter – Extremely faint, seen using averted vision, two stars appeared superimposed

 

Abell 61 – 18” / 73x / OIII Filter – Extremely faint, found using averted vision though I was able to hold it with direct vision after a few minutes

 

Abell 53 – 18” / 73x / OIII Filter – Faint, found using averted vision though I was able to hold it with direct vision after a few minutes, round shaped

 

Abell 62 – 22” – seen with direct vision, easy

 

PK 51-3.1 – No observation

 

I typically try to make a few observations of an object just to be sure I have actually seen it. Also, in almost every case I have a POSS image with me at the eyepiece to help identify the object in the surrounding star field. I have found an OIII filter is a requirement to see most, but not all on the list.

 

Below are some summer Abell’s other than the ones on your list that I found not difficult. None of these are described as being extremely faint in my notes:

 

Abell 39 – Her / 18”

 

Abell 43 – Oph / 18”

 

Abell 44 – Sgr / 22”

 

Abell 46 – Lyr / 18”

 

Abell 55 – Aql / 18”

 

Abell 60 – Sgr / 18”

 

Abell 62 – Aql / 18”

 

Abell 65 – Sgr / 18”

 

Abell 70 – Aql / 18”

 

Abell 72 – Del / 12 1/2”

 

Abell 78 – Cyg / 18”

 

Abell 79 – Cep / 22”

 

Good luck and let us know how you do.

 

Andrew


  • KidOrion, Allan Wade and Knasal like this

#4 RLK1

RLK1

    Viking 1

  • -----
  • topic starter
  • Posts: 519
  • Joined: 19 Apr 2020

Posted 12 August 2020 - 02:26 PM

Although my initial post in this thread noted the challenge objects for 16'/18" scopes, I decided to take my 12" ES scope out in front of my light-polluted home last night for general observing and while I couldn't detect the challenge objects themselves, I did observe PK 65 + 0.1, also known as NGC 6842, a magnitude 13.10 planetary identified in the Observer's Guide as being a "faint 50" disk with diffuse edges located in a rich star field":

http://www.kopernik....chive/n6842.htm

The Guide identifies the object as being in Cygnus, however, my sky commander and the above link identify it in Vulpecula. Either way, I was just jazzed to see it at all and I note the above link has the magnitude as 14!

I used a DGM NPB filter with a pentax 10.5mm eyepiece/paracorr combo under conditions of superb transparency and good seeing. 

I think I've got a chance of picking up a few of the 16/18" challenge objects under dark sky conditions with my 12" although I'll attempt them first with my 16". I like pushing the envelope on the the observable magnitudes of these objects, either under adverse or more favorable dark sky conditions....



#5 andreww71

andreww71

    Ranger 4

  • *****
  • Posts: 307
  • Joined: 07 Jul 2014
  • Loc: NE Ohio

Posted 12 August 2020 - 07:13 PM

Although my initial post in this thread noted the challenge objects for 16'/18" scopes, I decided to take my 12" ES scope out in front of my light-polluted home last night for general observing and while I couldn't detect the challenge objects themselves, I did observe PK 65 + 0.1, also known as NGC 6842, a magnitude 13.10 planetary identified in the Observer's Guide as being a "faint 50" disk with diffuse edges located in a rich star field":

http://www.kopernik....chive/n6842.htm

The Guide identifies the object as being in Cygnus, however, my sky commander and the above link identify it in Vulpecula. Either way, I was just jazzed to see it at all and I note the above link has the magnitude as 14!

I used a DGM NPB filter with a pentax 10.5mm eyepiece/paracorr combo under conditions of superb transparency and good seeing. 

I think I've got a chance of picking up a few of the 16/18" challenge objects under dark sky conditions with my 12" although I'll attempt them first with my 16". I like pushing the envelope on the the observable magnitudes of these objects, either under adverse or more favorable dark sky conditions....

Nothing wrong with pushing your scope to the limits. I do however recommend going after the challenging objects, such as Abell planetaries, during the most favorable conditions. 


  • KidOrion likes this

#6 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 47,400
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 14 August 2020 - 07:13 PM

I’ve been slowly picking away at the Abell planetary catalog since the mid 1990’s. I first started with an 18” F/4.5 scope, and then moved up to a 22” F/5. After a long hiatus I reentered the hobby and have continued to pick away at these often exceedingly faint objects, most recently with a 22” F/4.16. I’ve read reports of people seeing most of the catalog with similar sized scopes but they are observing under much darker skies than I am.

 

My notes for the objects you list:

 

Abell 71 – 18” / 73x / OIII Filter – Extremely faint, seen using averted vision, two stars appeared superimposed

 

Abell 61 – 18” / 73x / OIII Filter – Extremely faint, found using averted vision though I was able to hold it with direct vision after a few minutes

 

Abell 53 – 18” / 73x / OIII Filter – Faint, found using averted vision though I was able to hold it with direct vision after a few minutes, round shaped

 

Abell 62 – 22” – seen with direct vision, easy

 

PK 51-3.1 – No observation

 

I typically try to make a few observations of an object just to be sure I have actually seen it. Also, in almost every case I have a POSS image with me at the eyepiece to help identify the object in the surrounding star field. I have found an OIII filter is a requirement to see most, but not all on the list.

 

Below are some summer Abell’s other than the ones on your list that I found not difficult. None of these are described as being extremely faint in my notes:

 

Abell 39 – Her / 18”

 

Abell 43 – Oph / 18”

 

Abell 44 – Sgr / 22”

 

Abell 46 – Lyr / 18”

 

Abell 55 – Aql / 18”

 

Abell 60 – Sgr / 18”

 

Abell 62 – Aql / 18”

 

Abell 65 – Sgr / 18”

 

Abell 70 – Aql / 18”

 

Abell 72 – Del / 12 1/2”

 

Abell 78 – Cyg / 18”

 

Abell 79 – Cep / 22”

 

Good luck and let us know how you do.

 

Andrew

Abell 70 was amazing--the little edge-on galaxy on the "ring" is truly stunning.

And that was in a 12.5".  I'd love to see it in, say, a 28".



#7 RLK1

RLK1

    Viking 1

  • -----
  • topic starter
  • Posts: 519
  • Joined: 19 Apr 2020

Posted 14 August 2020 - 08:21 PM

Abell 70 was amazing--the little edge-on galaxy on the "ring" is truly stunning.

And that was in a 12.5".  I'd love to see it in, say, a 28".

That'll be on my list and I hope to observe it from Mt Pinos around new moon time in the next few days. Can't do any observing in front of my home right now because the Lake fire, about 20 miles NE of me, is causing intermittent haze and a smokey smell in the air, depending on the winds. Hopefully none of it will waft up to Mt Pinos but there's little containment of it at this time. It's gosh darn fire season in SoCal...




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






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics