(IAAC) Jones-Emberson 1 (JE1, PK 164+31.1, PN G164.8+31.1) - 17.5" F/4.5

Observer: Yann POTHIER (France)
Your skill: advanced (many years)
Date and UT of observation: 28 December 1997, about 23h50 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 5% of the time
Transparency (1 to 5 - best to worst): 1
Seeing (1 to 5 - best to worst): 3 (stellar stars until 180x)
Moon up (phase?): no
Instrument: Coulter 17.5" (445mm) F/4.5
Magnification: 211x
=46ilters used: OIII, UHC, Hbeta
Object: Jones-Emberson 1 (JE1, PK 164+31.1, PN G164.8+31.1)
Category: planetary nebula
Constellation: LYN
Object data: Vmag=3D12.1; dim.7'x6' (410"x365" according to IDB); type IV ;
central star of Vmag=3D16.8; discovered by Jones & al. in 1939
RA/DE: 07h57.8m, +53=B025' (2000); Uranometria 43
Description: at 125 and 211x with OIII, large PN, very faint, round with
ill-defined edges, with two brighter lobes or annular parts; about 5' in
diameter (estimated on drawing); the two lobes are about 1.85'x1.20' along
a N-S axis and situated on the approximate W and E borders (PA60=B0 & 240=B0=
brighter than the rest of the nebula; 5 stars of mag13 to 15 are scattered
on its surface; invisible without filter or just vague traces of it;
internal structure (lobes) accessible from 74x+OIII; UHC has a good
contrast gain, OIII a very good one and Hbeta has no gain (as quasi-usual).
I can provide a scanned drawing of JE 1 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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