Object of the Week September 9, 2012- Abell 70 (PK 38-25.1

Abell 70 (PK 38-25.1)

Aquila

RA
20 31 33

DEC
-07 05 18

Type PN and Galaxy

14.3 (P) MAG

Abell 70 is one of my all time favorite deep sky objects. There is nothing like getting two different types of objects for the price of one star hop. This faint ring really comes alive when I use the NPB filter but the back ground EO galaxy on the North side of the ring fades out with the filter. The back ground overlap EO looks best unfiltered at the highest power that the night will let you use so be sure to turn up the power for you're unfiltered view. I would like to here from you as to what is the smallest scope it takes to glimpse the back ground EO galaxy. I hope you will try this (TWO FER) in Aquila the next time you are under a clear dark sky and be sure to -

"GIVE IT A GO AND LET US KNOW"

GOOD LUCK AND GREAT VIEWING!
Attachment 296

Tomorrow morning I head off the island to a this star party. http://www.merrittastronomical.com/ I've just printed out the chart off Megastar. I'll let you know in a week what success I have with my 20". If I succeed then I'll see if anyone else with smaller scopes will let me try with theirs'.

Bill

Bill, I observed it with my Juno 14 some years ago. I found it best to observe both objects together with medium power and no filter. Getting there is not an easy star hop.

Off to CalStar - Nice object to track down. Pretty sure Paul Alsing showed it to me. But like Paul, I use the "new friends every night" observing method.

Agree on this being a real gem and one to revisit. Have a couple observations both of which describe a brighter side of the ring on the north but I had not known the galaxy was there till the second observation was logged and I noted it was a galaxy (my notes after the field are in brackets and either translate my fov measurements or state other facts from MegaStar.

This is from 7-29-2011 at Lassen Bumpass Hell lot with an amazing 21.7SQM, 6.9 NELM (extremely high for my eyes) and seeing 10/10 with transparency 8/10. This started at 216x for 9mm then 7mm was 278x in my 18" dob.

Abell_70: NPB filter shows a donut of 1/20fov diameter [0.63'] where averted indicates the central open or dimmer portion of about 1/3 the diameter or about 20" dia open area. It is still glowing but just darker with averted in the central area. 7mmNag unfiltered available averted 100% of the time. There is brightness along north side in a bright line 20 degrees from EW that does not show up with the NPB FILTER [This is a galaxy]

Got a chance to see it from NELM 6.4 skies at Cherry Springs State Park last Wednesday evening. I used a 22" f4.8 at 337x. My notes: "Seen without a filter; the O-III actually made it seem dimmer; the UHC was a bit better. With or without a filter, the northern part was definitely brighter and elongated (PGC-187663)." Thanks for the tip on the TWO-FER!

Al

That really was a fun object to observe. With my 20" at first what I was seeing was a bit confusing but with taking some time at 321X with a 6mm Ethos the defintition of the two separate objects started began to become clearer. The PN was rather elongated. The slash of the galaxy across the northen section was impresive. I put a UHC filter on which killed the galaxy so enjoyed the unfiltered look best. I tried showing this to someone else at the star party but they found it difficult. To me at that point of the evening it was easy as I had just finished observing 10 Palomar Globulars in a row. I never got a chance on anything smaller as the 12" Starmaster next to me was tied up and the next closest biggish scope was way across the field.

Thanks for the tip.

Bill

Also one of my favorite object in the sky Jimi, very cool OOTW. My experience with different aperture (all without filter):

16": galaxy is visible as a very faint spot at the N edge sketch
20": galaxy is easy to see as a faint, 1:3 elongated nebula, brighter second stellar spot at the S edge of the ring, no CS
24": galaxy is easy visible as 1:4 elongated nebula, easy to separate from the ring, no CS
27": impressive view, PN easy with direct vision, round ring, galaxy 1:3/1:4 elongated, concentrated to its middle

Two nights ago I finally observed this great planetary nebula. Definitely one of the easier Abells out there. My notes taken with my 20" read:

At 151x visible without filter. Round, not annular. Responds well to UHC.
At 256x visible without filter. Annular. Clearer visible with UHC and more with OIII.
At 320x without filter I see the galaxy as a brighter edge which disappears with UHC and OIII. Only with OIII visible as a ring.

We also observed it with a 12" using an UHC. Faintly visible without filter, clear with. Round, not annular. Galaxy not seen.