(IAAC) Supernova observations
Last night I managed to observe two of the three supernovae currently
visible in Ursa Major and thouight I saw the other.
The one I thought I saw was SN 1998T in NGC3690.
NGC 3690 is a colliding pair of galaxies, part of a cluster ARP 299 which
also includes a much fainter galaxy IC 694, which I did not search for last
night. The galaxy pair is a remarkable object and a worthwhile subject of
observation in its own right. It is quite small and condensed object so
despite its dim magnitude it is easily visible and represents the clearest
pair of colliding galaxies I have seen telescopically. The pair look like
what they are colliding oval galaxies. They have condensed central regions
with some structure visible. Using averted vision ( and imagination?)I
thought I saw the supernova near the crook where the two galaxies join.
Although subsequent examination of a net image of the supernova showed this
was the correct location, Gary Popyner of the BAA variable star section told
mew the SN was about 16 magnitude, too dim for my 20". What I probably saw
was a condensation in the galaxy.
The other two supernovae were easily visible in their parent galaxies giving
a vivid impression of how much energy they were releasing, the brightness of
each was approaching the brightness of the whole galaxy ( about 12 magnitude
for each). The galaxies with their pinprick stars are really beautiful,
currently a must for any deepsky observer. SN1998S is in NGC 3877 (RA 11hr
46 Dec+47 30) and SN 1998aq is in NGC3982 (RA 11 56.5 Dec +55 07)
Observations on SN 1998aq, SN 1998S 20" F4.4 Newtonian on Dobsonian mount,
Sky clear with patchy cloud
Object name Julian date Magn. Compstars Chart
SN 1998aq - 2,450,925.5000 126 121 122 124 130 AAVSO
SN 1998S 2,450,925.5000 130 125 126 132 136 AAVSO