(IAAC) PK 017-10.1 (Abell 51) - 17.5" F/4.5

Observer: Yann POTHIER (France)
Your skill: advanced (many years)
Object: Abell 51, PN G017.6-10.2, PK 017-10.1, PK 17-10 1, ARO 300,
IRAS 18581-1816
Category: planetary nebula
Constellation: SGR
Object data: Vmag=15.0, PHmag=15.4, diam.62" (67" in IDB), type IV,
central star UBV 161333 of Vmag=15.4 (sp. Sd 08k), uranometria chart
341; discovered by Abell in 1955; expansion velocity=84km/s (OIII);
ELCAT: OIII [496nm] = 2 x Hbeta [486nm].
RA/DE: 19h01m01s, -1812'06" (2000.0)
Date and UT of observation: 04 August 2002, 22h15 UT
Location & latitude: La Clapiere Obs. (France, latN44 40 00, longE06 27 36)
Site classification: rural, alt.1650m (5500ft)
Limiting magnitude (visual in UMi): 6.34 (less than 25% of the
observing time with averted vision)
Transparency (1 to 5 - best to worst): 2
Seeing (1 to 5 - best to worst): 4
Altitude of object above horizon: 27
Moon up (phase?): no
Instrument: Coulter 445mm/17.5" F/4.5
Magnification: 74x, 125x
Filters used: UHC, OIII, Hbeta
Description: at 183x with OIII filter, medium sized PN, extremely
faint, round with ill-defined edges, homogeneous but very slightly
brighter center; about 46" in diameter (on drawing); UHC and Hbeta
filter are not helping and OIII filter gives a small contrast gain; a
mag.11 star stands 2' to the SW.
I can provide a scanned drawing of PK 017-10.1 (Abell 51) to anyone
who can read the binhex encoding of Eudora (for Mac); just mail me to
try (yann.pothier@fnac.net), it works quite often with other
Carpe noctem, Yann.
Yann Pothier
11 impasse Canart, 75012 PARIS, FRANCE
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