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(IAAC) Abell 33 (PK 238+34.1; PN G238.0+34.8) - 17.5" F/4.5



Observer: Yann POTHIER (France)
Your skill: advanced (many years)
Date and UT of observation: 02 February 1995, about 02h00 UT
Location & latitude: La Clapiere Obs. (France, latN44 40 00, longE06 27 36)
Site classification: rural, alt.1650m (5500ft)
Limiting magnitude (visual in UMi): 6.0 with averted vision
Transparency (1 to 5 - best to worst): 1
Seeing (1 to 5 - best to worst): 3
Moon up (phase?): no
Instrument: Coulter 17.5" (445mm) F/4.5
Magnification: 145x
Filters used: UHC, OIII
Object: Abell 33 (PK 238+34.1; PN G238.0+34.8; ARO 65)
Category: planetary nebula
Constellation: HYA
Object data: Vmag=12.6; Bmag=13.4; dim.268"x215"; type IIb PN; central star
of Vmag=15.66; discovered by Abell in 1955; ELCAT: [OIII, 496+501nm] = 15 x
[Hbeta, 486nm].
RA/DE: 09h39.1m, -0248' (2000); Uranometria 233

Description: at 145x and OIII, large PN, oval NE-SW, very very faint, quite
sharp edges, darker center with portions of ring seen on the W, NW and N
borders; estimated to be 268"x215"; UHC has a good response and OIII a very
good one; a mag8 star touches the SW edge (and degrades a bit the viewing);
one mag13 and two mag14 stars are forming a group on the N part of the
ring; the nebula is invisible at 74 and 87x without filter; suspected at
125x as a halo extending from the mag8 star.

Note1: an error occured in JC Vickers' CCD Atlas North concerning his shot
of Abell 33 (confirmed by correspondance with him).

Note2: the nebula looks larger, more circular and homogeneous on POSS red
plate (as in DSS).

I can provide a scanned drawing of Abell 33 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
configurations...

Yann Pothier
11 impasse Canart, 75012 PARIS, FRANCE
ypothier@abi.snv.jussieu.fr
ypothier@closun.snv.jussieu.fr
http://www.astrosurf.org/cielextreme
http://www.astrosurf.com/cielextreme
http://astrosurf.org/skylink/publi/cielextreme,


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