On Apr 18, 2005, at 3:11 PM, Mark Wagner wrote:
> I think a more appealing list would be interesting pairs. NGC 6946
> and NGC 6939 are a prime example. Steve Gottlieb had an article in
> S&T not too long ago using this theme. Anyone have some
> recommendations? Which Abell Planetary has the galaxy showing through
> the edge of its ring?
The July '03 article in S&T includes mostly challenging pairs rather
than eye-candy (M57/IC 1296, etc.), but if anyone would like to see a
copy, I can attach it as a .pdf (contact off list). Has anyone
mentinoned gc NGC 6712 and pn IC 1295?
Abell 70 has an uncatalogued galaxy shining through its rim! I've
looked at this one a number of times –
18" (9/20/03): at 160x, visible without a filter although the contrast
is slightly improved with a UHC filter. Appears faint, fairly small,
roundish, 35" diameter, slightly irregular surface brightness. At 257x
without a filter a very small, brighter "knot" (galaxy) is definitely
visible on the N side. Two mag 14 stars are off the SW and SE sides
and another mag 14 star lies 1.5' NNE.
17.5" (8/16/01): picked up at 220x without filter and an excellent view
at 280x. The PN appears slightly elongated NW-SE, ~40"x35" with a
clearly irregular surface brightness. The galaxy shining through the
north side is visible as a brighter "knot", but with extended viewing
this enhancement is elongated WNW-ESE, perhaps 15"x8". A faint star is
~30" off the SW side with a brighter star ~45" off the SE edge. Modest
contrast gain with UHC filter although the brightening along the N side
was slightly more difficult to detect.
17.5" (8/12/96): picked up without problem at 100x using an OIII filter
as a 40" disc with a slightly brighter streak running along the north
side. The PN is visible unfiltered but the streak and disc are dimmer
to view. Seen well without filter at 220x where the disc is a bit more
prominent and still brighter along the north side.
17.5" (7/31/92): easily visible at 100x using an OIII filter and can
hold steadily with direct vision. Fairly faint, fairly small, almost
round, 30" diameter, estimate V = 14.0-14.3. Visible without filter
using averted vision. At 220x viewed without filter; faint, fairly
small, appears to be brighter along the N side, edges not as crisp
using this higher power. The brightening detected along the N edge of
the rim at 220x is assumed to be a very faint anonymous galaxy shining
through the planetary.
Steve
Received on Mon Apr 18 17:45:29 2005