|
meteoptic-l [ät] ursa.fi
message archive
This is meteoptic-l [ät] ursa.fi message archive.
Note, your can reply the messages on this page only if your
are already subscribed the list.
» To the end of the list/message
>From latitude 43o56'30" on July 15/16, I observed an extended
sky-brightening in
the east, starting at 2:12 am, extending up 15o at it's highest. It showed
no
details or outstanding features, and did not appear to obscure the sky
behind
it. It was not truly dome-shaped, extending only about 20o in azimuth, but
I
assumed it was most likely twilight at the time, as this was a new and
very dark
location for me, and I was unsure of the start of local astronomical
twilight.
However, I've since checked an ephemeris for that location (actually
'xephem'),
and it lists the beginning of astronomical twilight for that morning as
02:32
local time. I did NOT note how it changed while true twilight approached,
or I
might have been able to confirm this sighting one way or another.
So what should I assume this was? An NLC sighting at a record low
latitude, or
an indication of just how early twilight can begin in a truly dark
Northern sky?
Comments appreciated,
Lew Gramer
|