Photo of the Week. From the deep south comes
Pavo
(the Peacock), featuring the luminary Alpha star (itself "Peacock")
and the globular
cluster NGC 6752, 15,000 light years away.
Astronomy news for the week starting Friday, September 24,
2010.
As busy as last week was, this one is quiet, the sky not much
caring about doing things week by week. Yet there is a charm to
it, as we embrace
Moon-phases of the moment. Full Moon
took place last Thursday morning (September 23), while the last quarter is hit on the evening of
Thursday the 30th (about the time of, or shortly before, Moonrise
in North America), leaving practically the entire week for the waning gibbous, the day-night line on the
Moon (the "terminator") sweeping from right to left. A telescopic view of this dividing line, where
the Sun is setting on the Moon and shadows are long, reveals a
spectacular number of craters
.
The evening sky features a rather distant conjunction between
brilliant Venus and
not-so-bright Mars on Tuesday the
28th, Venus passing six degrees south of the red planet, which
hovers at the edge of second magnitude and will be near-impossible
to see in twilight, both planets now setting before the sky is
fully dark. Saturn, long lost to us, makes a bit of a
comeback by invisibly passing conjunction with the
Sun the night of Thursday the 30th, just three hours before the
Moon passes third quarter.
The later planetary evening sky thus belongs now to bright Jupiter, which,
having passed opposition to the Sun last Thursday (the 23rd), is
already up in the east (still in western Pisces) by the time the sky darkens. After
crossing the meridian to the south
around 12:30 AM Daylight Time, the giant planet can be seen way in the
west by the time of morning's first light. Look then also for
little Mercury,
which can be seen low in the east just after the commencement of
dawn.
The morning hours also bring us the stars that will eventually
grace winter skies, allowing us to admire them with some warmth
left in the air. As the morning sky brightens, find Sirius in the southeast, with Orion up and to the right. In the
evening, though, the summer's stars are still with us, Sagittarius low in the south. If you
live far enough to the south and have a clear southern horizon,
look for the gentle curve of stars below the Archer that makes Corona Australis, the Southern Crown.
From the deep south, you might even spot the bright luminary of Pavo the Peacock sticking up just a
bit over the horizon down the to the left.
