(IAAC) M 2-51 (PK 103+00.1; PK 103+0 1; PN G103.2+00.6) - 17.5" F/4.5

Observer: Yann POTHIER (France)
Your skill: advanced (many years)
Date and UT of observation: 14 August 1997, about 01h50 UT
Location & latitude: La Clapiere Obs. (France, latN44 40 00, longE06 27 36)
Site classification: rural, alt.1650m (5500ft)
Limiting magnitude (visual in UMi): 6.4 with indirect vision in UMi 30% of
the time
Transparency (1 to 5 - best to worst): 1
Seeing (1 to 5 - best to worst): 2 (stellar stars until 211x)
Moon up (phase?): no
Instrument: Coulter 17.5" (445mm) F/4.5
Magnification: 400x
=46ilters used: OIII, UHC, Hbeta
Object: M 2-51 (PK 103+00.1; PK 103+0 1; PN G103.2+00.6)
Category: planetary nebula
Constellation: CEP
Object data: Vmag=3D13.5; dim>41" ; central star GSC 3990-815 of V=3D13.6;
discovered by Minkowski in 1947; ELCAT: OIII [496+501nm]=3D 12.5 x Hbeta
RA/DE: 22h16.1m, +57=B029' (2000); Uranometria 57;

Description: at 400x and UHC, medium to large PN, faint without filter and
better seen with filter; round, fuzzy edges with filter but ill-defined
without; already visible at 74x and UHC; a little brighter center;
estimated diameter of about 49"; central star of mag14 seen on the disk
along with 2 stars of mag15 at 21"SSW and 26"NE; mag13 stars at 1.3'SW and
2.0'NE; both UHC and OIII filters have the same good contrast gain, with
Hbeta having no effect.

I can provide a scanned drawing of M2-51 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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