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View Full Version : Object of the Week July 17th, 2016 – Peimbert-Costero 22



Uwe Glahn
July 17th, 2016, 09:22 PM
Peimbert - Costero 22 (PC 22)
PN G 051.0-04.5 (PK 051-04.1)
RA: 19h 42m 03.5s
DEC: +13° 50' 37"
Size: 20"

Beside the famous NGC/IC Planetary Nebula we all know the Minkowski’s and the Kohoutek’s, of course also the Abell’s. But next to them the knowledge of the numerous catalogues drops. This is of course the difficult observation which concerns the faint brightness or often the very small angular size <5” which let the PN looks like a star.

Today we meet one of the very rare exceptions – “Peimbert-Costero 22”.

But WTF is PB 22? “P” stands for the person Manuel Peimbert, “C” for Rafael Costero – both Mexican astronomers who worked at the Tonantzintla Observatory (Bill Keel's presentation (http://pages.astronomy.ua.edu/keel/telescopes/tonantzintla.html)) near Puebla, Mexico. They published a list (the second list of them) of 14 new discovered PN (Nuevas Nebulosas Planetarias II (http://www.astroscu.unam.mx/bott/BOTT..3-21/PDF/BOTT..3-21_mpeimbert.pdf)) which were found trough objective prism plates with the 28-inch Schmid camera.

Number 22 is the goal this week. With 20" it belongs to the bigger PN. I noted "nonstellar from 100x up". With the brightness it could be a goal already for the 8" class. With higher magnification the rectangular for is obvious and good good seeing brings out some detail within the brighter rim. I could not detect any CS, one source says 18.1mag.

DSS blue, 30'x30'
2198

IAC (Bruce Balick)
2199

sketch: 27", 837x, no filter, NELM 6m5+, Seeing II-III
2200

GIVE IT A GO AND LET US KNOW

Steve Gottlieb
July 17th, 2016, 10:51 PM
This is one of the largest Peimbert-Costero planetaries and a nice object that should be better known!

My last observation was in 2001 using a 17.5" -- PC 22 was found at 220x (without filter) as a fairly faint oval, elongated nearly 2:1 SW-NE, ~20"x12" with a mag 13 star at the NE end and a brighter mag 12 star 1' SE. At 380x, a very faint companion is just ENE of the mag 13 star. PC 22 is interesting at high power with a relatively high surface brightness and an unusual elongation. Located 14' ENE of mag 6 SAO 105132 = QS Aquilae.

Back on 2 August 1986 I made what may be the first visual observation -- "at 220x a nice 10"-15" disc is visible, estimate V = 13.0-13.5. Appears slightly elongated with a faint star at the east end."