(IAAC) M 2-55 (PK 116+08.1; PK 116+8 1; PN G116.2+08.5) - 17.5" F/4.5

Observer: Yann POTHIER (France)
Your skill: advanced (many years)
Date and UT of observation: 20 December 1992, about 20h30 UT
Location & latitude: La Clapiere Obs. (France, latN44 40 00, longE06 27 36)
Site classification: rural, alt.1650m (5500ft)
Limiting magnitude (visual in UMi): 6.2
Transparency (1 to 5 - best to worst): 2
Seeing (1 to 5 - best to worst): 4
Moon up (phase?): no
Instrument: Meade 8"/203mm F/10
Magnification: 145x
=46ilters used: OIII, UHC
Object: M 2-55 (PK 116+08.1; PK 116+8 1; PN G116.2+08.5)
Category: planetary nebula
Constellation: CEP
Object data: Vmag=3D14.2; dim.40"x40" (66"x40" according to IDB); type III;
central star ?; discovered by Minkowski in 1947; ELCAT: OIII [496+501nm]=3D
12 x Hbeta [486nm]
RA/DE: 23h31.9m, +70=B023' (2000); Uranometria 15;
Description: at 145x, very faint nebula, small to medium in size, only seen
with OIII filter between 87 and 145x; seen 50% of the observing time,
fleeting in averted vision; UHC has a smaller contrast gain than OIII;
homogeneous and about 33" in diameter; the PN forms a triangle with 2 mag11
stars at 2'NNE and 1'ESE.
I can provide a scanned drawing of M2-55 to anyone who can read the binhex
encoding of Eudora (for Mac); just mail me to try
(ypothier@abi.snv.jussieu.fr), it works sometimes with other
Yann Pothier
11 impasse Canart, 75012 PARIS, FRANCE
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