Re: Evening viewing
Sean Sullivan (tssulliv@unix.amherst.edu)
Sun, 11 Jan 1998 10:20:02 -0500 (EST)
The OAO-2 and OAO-3 rocket bodies, along with the Centaur 2 test vehicle,
have the distinction of being the only Centaur stages in LEO. Thus, it
is understandable that they would be spectacular objects quite often.
They have rather slow tumbles in comparison to the GTO Centaurs that I
like to observe, so the LEO objects seem a little erratic if one doesn't
follow them for awhile.
The OAO-2 and OAO-3 spacecraft are also visually interesting. Both s/c
produce occasional brilliant glints (negative magnitudes), perhaps from
the mirror (?) though it could be some other flat surface. Of the two, I
have found OAO-3 to be more reliable at producing flares. It seems to have
a tumble period around 1 min (haven't seen it in a few years, since I moved
north) and would vary in a complex pattern between mag 7 and mag 1, with the
mag 1 flash quite brief but regular, preceeded by a long plateau around mag
3. In contrast, OAO-2 never flared when I specifically went to look at it,
and seemed fairly constant in mag, but quite a few times it made an
appearance as an unid bright sat.
OAO-3 (also known as Copernicus) is one of my favorite satellites, nearly
on par with even EGP/Ajisai, although harder to spot (it slips by easily
when it's in its faint period of the cycle). Complex light curve,
brilliant flares on a regular basis ... it has it all.
I've tried looking at the OAO-1 objects, and never noticed anything
noteworthy about them. The rocket was an Agena-D, and looked like all the
rest.
-- Sean Sullivan
On Sun, 11 Jan 1998, Craig Cholar wrote:
> Jeff Hunt mentioned an UNID he saw that was almost as bright as Saturn.
> He said that OAO 2 rk (3598/68110B) matched the track, but he doubted
> that it could get that bright. I've seen it get as bright as mag 1,
> and there are quite a few PPAS entries that show it getting that bright.
> The other OAO objects can occasionally put on a good show, so they are
> on my 'always look' list.
>
> OAO 1 02142 66 31A
> OAO 1 Rk 02144 66 31B
> OAO 2 03597 68 110A (I saw this glint to -2 once)
> OAO 2 Rk 03598 68 110B
> OAO 3 06153 72 65A
> OAO 3 Rk 06155 72 68B