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(IAAC) Obj: PK 22-3.1 (M1-58), PK 22-2.1 (M1-57) - Inst: 20" f/5 dob newt
Observer: Lew Gramer
Your skills: Intermediate
Date and UT of Observation: 1997-07-31/08-01, 04:45 UT
Location: Savoy, MA, USA (42N, elev 700m)
Site classification: rural
Limiting magnitude: 7.2 (zenith)
Seeing: 7 of 10 - pretty good
Moon up: no
Instrument: 20" f/5 Tectron truss-tube dob Newtonian reflector
Magnification: 420x (70x, 210x - NOPE)
Filters used: OIII
Object: PK 22-3.1 (M1-58), PK 22-2.1 (M1-57) (? - see note below)
Category: Planetary nebulae [both Type 2]
Constellation: Sct
Data: mag 12.4, 14 size 7"x6", 9"x8"
RA/DE: 18:42:57.0 -11:06:55.0, 18:40:20.20 -10:39:48.0
Description:
The field for these two FAINT challenge-objects was readily found
2o SW of delta Sct, near a pretty broad-based "diamond" of finder
stars - mags 7, 7, 8 and 9. About 10' W of the mag 7 vertex star
to the E, and then about 40' SW of there, near the center of the
SW edge of the parallelogram, were respectively found two stellar
objects that responded to OIII blinking, but only when averted
vision AND either field motion or concentrated vision (either of
these worked) were used. Even with all these tricks, neither of
these tiny planetaries was visible at 70x or 210x, both requiring
420x to be seen under any conditions.
--
FAINT is an understatement: but it can be interesting to find out
the true deep-sky limits of your vision, training, and scope!
Interestingly, no brightness difference between these was noted.
--
[NOTE: The attribution of the second (E-most) of these two objects
is uncertain: both are plotted as planetaries without designation
on Herald & Bobroff's "AstroAtlas" C-Series charts, and PK 22-2.1
is the nearest deep-sky object to the position of the second haze!]
--
[Later Note (02 Jun 2004): Viewing the result of a SIMBAD query in
the "Aladin" online plotting tool verified that these two PNe are
in fact distinct objects, within about 40' of each other...]