Nova?

We were having a little beach party on a Saturday night (9/20/2003) on
the shores of Lake Superior just outside Marquette MI. The sky was
clear and the Milky Way was very beautiful. Mars was quite bright,
and my wife and i even saw a satellite pass over. Then my father
pointed out a bright light in the northern sky. It was brighter than
Mars. It even appeared to have a halo. I don't know when it started,
but we watched it for maybe a minute or more. Then it faded to the
brightness of a dim star. It did not move relative to the other
stars. After it faded, i checked my watch. It was 9:20 p.m., Eastern
time. I'm not as familiar with the constellations as i would like to
be, but my wife was sure that it was in Perseus.

Does anyone have an idea about what we saw that night? From what i
have read, it sounds like variable stars don't shine that bright, and
novas last for days.

Thanks for your help,
--david kristola

"David Kristola" wrote in message
om...
We were having a little beach party on a Saturday night (9/20/2003) on
the shores of Lake Superior just outside Marquette MI. The sky was
clear and the Milky Way was very beautiful. Mars was quite bright,
and my wife and i even saw a satellite pass over. Then my father
pointed out a bright light in the northern sky. It was brighter than
Mars. It even appeared to have a halo. I don't know when it started,
but we watched it for maybe a minute or more. Then it faded to the
brightness of a dim star. It did not move relative to the other
stars. After it faded, i checked my watch. It was 9:20 p.m., Eastern
time. I'm not as familiar with the constellations as i would like to
be, but my wife was sure that it was in Perseus.

Does anyone have an idea about what we saw that night? From what i
have read, it sounds like variable stars don't shine that bright, and
novas last for days.

Thanks for your help,
--david kristola

Other than the bit about not moving, and lasting a minute, what you saw
sounds a lot like an "Iridium Flare" caused by specular reflection from the
solar panels on a satellite. So possibly it was a high altitude spy
satellite in a polar orbit. Iridium satellites are in relatively low
polar/high inclination orbits and move visibly; the flares can be bright
enough to be seen in daylight and last maybe 10 seconds.

The halo might be due to a small amount of cirrus cloud or haze that you
couldn't see.

Iridium Flares can be checked and predicted on the website

http://www.heavens-above.com/

Unfortunately, they only keep details on flares for about 48 hours before
present, so you can't check something two months old. You can get local
predictions a week ahead.

Alternative identification might be a high altitude military aircraft with
its landing lights on. When I worked at Palomar the B52s and C5As coming in
to land at a local base would sometimes fly over and spoil my efforts at
photometry. They were supposed to avoid the area. They were often so quiet
that you would see the light but not hear the engines.

--
Mike Dworetsky

(Remove "pants" spamblock to send e-mail)

Mike Dworetsky wrote:


"David Kristola" wrote in message
om...
We were having a little beach party on a Saturday night (9/20/2003) on
the shores of Lake Superior just outside Marquette MI. The sky was
clear and the Milky Way was very beautiful. Mars was quite bright,
and my wife and i even saw a satellite pass over. Then my father
pointed out a bright light in the northern sky. It was brighter than
Mars. It even appeared to have a halo. I don't know when it started,
but we watched it for maybe a minute or more. Then it faded to the
brightness of a dim star. It did not move relative to the other
stars. After it faded, i checked my watch. It was 9:20 p.m., Eastern
time. I'm not as familiar with the constellations as i would like to
be, but my wife was sure that it was in Perseus.

....snip...

Alternative identification might be a high altitude military aircraft with
its landing lights on. When I worked at Palomar the B52s and C5As coming in
to land at a local base would sometimes fly over and spoil my efforts at
photometry. They were supposed to avoid the area. They were often so quiet
that you would see the light but not hear the engines.

Rob Kennicutt (head editor of the Astrophysical Journal these days) has
an amazing plate taken with the Palomar Schmidt showing the result of
the autoguider attempting to lock onto a B-52's landing lights
during an exposure of (IIRC) NGC 2403. Very entertaining as long
as they weren't my data...

And back on-topic, you can run the heavens-above flare predictions
backwards - the fastest way is to ask for the next 7 days, then
repeatedly use the "previous" link. However, I cannot vouch for
whether it pulls out the proper historical orbital elements.
I ran it backward for Marquette, and (voila!) there was a flare
of magnitude -2 at 2120 EDT! It was fairly low in the sky (30 degrees
or so, due north), which makes the satellites move slowly enough
that without a good reference star, they can look pretty stationary.
And (for non-Iridium spotters) the flare could appear as bright
as mag -7 depending on exactly where the observer was within
about a 35-km band.

Bill Keel

"William C. Keel" wrote in message
...
Mike Dworetsky wrote:


"David Kristola" wrote in message
om...
We were having a little beach party on a Saturday night (9/20/2003) on
the shores of Lake Superior just outside Marquette MI. The sky was
clear and the Milky Way was very beautiful. Mars was quite bright,
and my wife and i even saw a satellite pass over. Then my father
pointed out a bright light in the northern sky. It was brighter than
Mars. It even appeared to have a halo. I don't know when it started,
but we watched it for maybe a minute or more. Then it faded to the
brightness of a dim star. It did not move relative to the other
stars. After it faded, i checked my watch. It was 9:20 p.m., Eastern
time. I'm not as familiar with the constellations as i would like to
be, but my wife was sure that it was in Perseus.

...snip...

Alternative identification might be a high altitude military aircraft
with
its landing lights on. When I worked at Palomar the B52s and C5As
coming in
to land at a local base would sometimes fly over and spoil my efforts at
photometry. They were supposed to avoid the area. They were often so
quiet
that you would see the light but not hear the engines.

Rob Kennicutt (head editor of the Astrophysical Journal these days) has
an amazing plate taken with the Palomar Schmidt showing the result of
the autoguider attempting to lock onto a B-52's landing lights
during an exposure of (IIRC) NGC 2403. Very entertaining as long
as they weren't my data...

And back on-topic, you can run the heavens-above flare predictions
backwards - the fastest way is to ask for the next 7 days, then
repeatedly use the "previous" link. However, I cannot vouch for
whether it pulls out the proper historical orbital elements.
I ran it backward for Marquette, and (voila!) there was a flare
of magnitude -2 at 2120 EDT! It was fairly low in the sky (30 degrees
or so, due north), which makes the satellites move slowly enough
that without a good reference star, they can look pretty stationary.
And (for non-Iridium spotters) the flare could appear as bright
as mag -7 depending on exactly where the observer was within
about a 35-km band.

Bill Keel


Thanks for the tip on backdating Iridium predictions! And for the
interesting anecdote on aircraft over Palomar.

--
Mike Dworetsky

(Remove "pants" spamblock to send e-mail)

"William C. Keel" wrote in message ...
Mike Dworetsky wrote:


"David Kristola" wrote in message
om...
We were having a little beach party on a Saturday night (9/20/2003) on
the shores of Lake Superior just outside Marquette MI. The sky was
(snip)

...snip...

Alternative identification might be a high altitude military aircraft with
its landing lights on. When I worked at Palomar the B52s and C5As coming in
to land at a local base would sometimes fly over and spoil my efforts at
photometry. They were supposed to avoid the area. They were often so quiet
that you would see the light but not hear the engines.

Rob Kennicutt (head editor of the Astrophysical Journal these days) has
an amazing plate taken with the Palomar Schmidt showing the result of
the autoguider attempting to lock onto a B-52's landing lights
during an exposure of (IIRC) NGC 2403. Very entertaining as long
as they weren't my data...

And back on-topic, you can run the heavens-above flare predictions
backwards - the fastest way is to ask for the next 7 days, then
repeatedly use the "previous" link. However, I cannot vouch for
whether it pulls out the proper historical orbital elements.
I ran it backward for Marquette, and (voila!) there was a flare
of magnitude -2 at 2120 EDT! It was fairly low in the sky (30 degrees
or so, due north), which makes the satellites move slowly enough
that without a good reference star, they can look pretty stationary.
And (for non-Iridium spotters) the flare could appear as bright
as mag -7 depending on exactly where the observer was within
about a 35-km band.

Bill Keel

Thanks very much! While a satellite flare isn't as cosmic as a nova,
it is very interesting. Due north, 30 degrees, 2120 EDT. That is the
right place and time. I guess my perception of time was a little off
(10 seconds can seem like a minute here in Silicon valley when the
ground is shaking).

The new Marquette airport used to be a SAC base. When i first looked
up and saw the light, "B-52" came to mind. But there was no apparent
motion as there would be with a plane (and if it was at a very high
altitide, it would not have been so bright). I guess that the angular
motion was small enough that i wasn't able to notice it. After the
flare faded, i checked the time then looked back at the sky. I wasn't
sure which "star" it had been, but there were a number of dim stars in
the area (about the brightness of a satellite). I didn't watch for
long. Perhaps i would have seen it move if i had.

The interesting thing is that i work with some people who worked on
Iridium, and my cube is in the same building where the solar panal was
probably made.

Thanks again!
--david kristola