re: What did I see? Was it a new Lacrosse?

From: Walter Nissen <dk058_at_cleveland.Freenet.Edu>
Date: Sun, 28 May 1995 12:24:43 -0400
>         May 19 at about 11:45 PM or so (+-20 minutes) I saw a VERY BRIGHT,
> VERY RED, and VERY SLOW satellite go over, due overhead, from North to South.

Thank you very much for posting this observation.  You provided some very
interesting information and it may be that it will lead to an
identification of the object.

I used QuickSat to search my file of 1000 potentially bright LEOs for a
candidate which would have culminated above 70 degrees within the 40
minute interval you give.

  36.198  95.888  500.    Tulsa, OK  <--------- 1950  8.5 70 F F F F F
***  1995 May  20  *** Times are UT ***   216 1021
14521 C* 1510
 4 29 32   .0 82 251 C 142 21.4   47.3 1516 661 1527 1.0  63 1318  33.4
18340 C* 1875-80 r                    20.0  bt
 4 37 29   .0 84  80 C 143 21.2   43.3 1458 508 1464 1.1  59 1430  37.0

C* 1510             73.6
1 14521U 83115A   95136.44759628 -.00000004  00000-0  10000-3 0  8943
2 14521  73.6140  44.2348 0027282  39.2410 321.0571 12.41039306520488
C* 1875-80 r
1 18340U 87074G   95136.81418385  .00000027  00000-0  10000-3 0  7973
2 18340  82.5680  39.7687 0042003  44.2037 316.2387 12.55488680352340

Neither of these candidates seems very promising, and one isn't even in
what I would call a polar orbit, but then neither are the Lacrosses (57
and 68); I think you may be trying to say this wasn't like HST which is in
a tropical orbit.  I observed the G object on the 23rd and it wasn't
remotely near mag -1.  It may be that someone with a larger file of elsets
will find more candidates.

A curious thing happened.  You wrote me asking if I had seen your post.  I
didn't recall seeing it, checked my archive, and then sent an "archive
egrep delli latest/*" to seesat-l-request to see if I had missed
something.  Within minutes of my receipt of an empty response from that
archive, your post appeared.  I guess it must be a coincidence, yes?  I
couldn't have jarred it loose?

I find your use of the term "very slow" to be somewhat helpful, even
though I have no precise idea what that means.

I hope that you will not feel targeted if I take this occasion to try to
draft an answer to this FAQ:  "What information will be required to
identify or reobserve my satellite?"

I'm probably not the most qualified to do so, but it seems worthwhile, so
here goes.

The reason this is such an interesting question is that it has no quick,
highly satisfactory answer.  If your satellite is as bright as Jupiter, it
may well be Mir or a shuttle and get a quick, off-hand reply, which will
very likely be correct.  If the approximate time, magnitude, direction of
travel, and behavior don't match up with anything obvious, your
observation becomes much more valuable and may lead to an extensive search
and require the most precise information available.

The more and better the information available the more useful it will be.
Many people regularly time astronomical events (including occultations) to
within about .2 seconds.  Most anyone can achieve this accuracy with a
little care.  An ordinary watch and one of the national time services will
suffice.  1 second accuracy should be a slam-dunk if the event is sharp
enough to permit it.  Routinely, positions accurate to 2 minutes of arc
are measured relative to the background stars.  One observation to .2
seconds of time and 2 minutes of arc is very valuable.  It should
eliminate at least 7998 of the 8000 objects for which elsets are available
(I think this is about right for OIG; and consider that there are 41253
square degrees in the sky).  A second such observation will make it
possible to produce a preliminary orbit which will greatly facilitate
attempts to reobserve the object within the next few days.  Perhaps the
RGO has specific guidelines in this area.

I made a rather poor quality observation of an UnID a couple weeks ago,
but I did get an appulse with a star and a general area about 100 seconds
earlier.  This was sufficient for Rainer Kracht (danke sch"on to you, sir)
to make a very satisfactory identification.  Yesterday I had a lot of
trouble getting good data on Spektr in the twilight, and reporting it when
I was extremely exhausted), but perhaps it will prove useful.

If the object is flashing, you can time the flashes, though astrometric
positions would be more useful in identification.  Any flashes, clouds
emitted from the satellite, colors, etc., can provide valuable clues.
Report the UTC and also, unless frequent use has resulted in a comfort
level with UTC, your VIT (village idiot time) if that was what you used.
Novices screw up the conversion to UTC with astonishing regularity.

If you don't know how to get accurate time, call someone within an hour or
two and get it done right.  If you have an accurate position, or other
interesting event such as an occultation or an explosion, and a reason to
think it may be of interest, you can call me at 1-216-243-4980, 24 hours a
day, and I will tell you to call 1-900-410-TIME or give you a frequency
(2.5, 5, 10, 15, 20 or 25Mhz) for a national time service, 3.33, 7.335, or
14.67 MHz for CHU, Ottawa, or do whatever can be done to get accurate
time.  Even if you are backpacking with a poorly set watch and it takes a
day to walk to a radio or a phone, you can carefully track the error in
the watch for a day or so and possibly get a very useful time for your
observation (a badly set clock may slew at some horrible rate, but the
slew may be stable; as a result I never reset my watch, I just record
carefully its behavior).

You cannot rely on commercial radio and TV networks to provide accurate
time, nor on long distance phone calls (you can call 202-653-1800 within
the Washington, DC, area and 303-499-7111 within the Fort Collins area),
and sometimes the CBS radio hour marker is very close (I think some
stations are using disks now to record the news and play it a few seconds
late), and I guess the six pips on BBC are still good provided you are not
listening to a tape, as on US stations (they claim to be on GMT, but no
one keeps that any more and I assume the six pips are actually UTC).  In
the US, local telephone time services are notoriously unreliable, but this
is not true everywhere.

Make a sketch of the star field for each position you record, and its
general location in the sky.  If a satellite passes between two stars you
should be able to estimate a proportion of the distance between them, like
1/3 or 3/5 of the way from the brighter to the fainter.  If you can do
this in tenths, that's great.  If you have to, you can extend such a fence
beyond the space between them.

Errata:  Spektr was about the same magnitude as Altair when I saw it near
Altair yesterday (perhaps .1 mag brighter than Altair), so it was roughly
mag 0.8 then; and I left out a question mark in reporting the magnitude of
the glint; it should have been mag -3(?); being far brighter than Jupiter
which was very low near the horizon (there was some cirrus) and not as
useful a reference as I might have hoped.  Fatigue has its price; my
apologies for the sloppiness of the message I sent out a few minutes
before I collapsed.

Received on Sun May 28 1995 - 12:41:01 UTC

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