|
NEW SUNSPOT:
The Solar and Heliospheric Observatory (SOHO) is monitoring
a sunspot now forming in the sun's northern hemisphere. The spot's
high latitude and magnetic polarity identify it as a member of new
Solar Cycle 24. Readers, if you have a solar
telescope, now is the time to watch sunspot genesis in action.
COMET LULIN AT ITS
BEST: Today, Feb. 24th, Comet Lulin is making
its closest approach to Earth. The speedy green comet is about 38
million miles away and a fine target for backyard telescopes. In
fact, the comet is so bright, around 5th magnitude, a camera may
be all the optics you need. Consider this photo of Comet Lulin passing
by Saturn last night:
Joe Wheeler of Fort Davis, Texas, took the picture using a Canon
XSi. "I mounted the camera on the back of a 16-inch telescope
at the McDonald Observatory and opened the shutter for a two-minute
exposure." The telescope tracked the stars and the camera did
the rest. "Look between Saturn and the comet," points
out Wheeler. "I think I caught a tumbling satellite."
The next 24 hours could be an interesting time for Comet Lulin.
The comet is going to line up almost perfectly with the Sun and
Earth as follows: Sun-Earth-Lulin. This could make the dust in the
comet's tail briefly but significantly increase in brightness--a
phenomenon astronomers call "the
opposition effect." So don't stop watching; the best may
be yet to come. Feb.
25th sky map.
UPDATED: Comet
Lulin Photo Gallery
[Comet
Hunter Telescope] [Sky maps: Feb.
22, 23,
24, 25]
NEW ZEALAND SUNDOGS:
Sundogs normally travel in pairs,
but on Feb. 20th, Graham Palmer of Hastings, New Zealand, came upon
a larger pack:
Photo details: Canon 40D, ISO
100, 1/250th second, 15mm fisheye lens
"I went for a walk in the park to catch two nice sundogs,
but was surprised to see a third," says Palmer, who recorded
the gathering using his Canon
40D.
Sundogs (the ones in the sky) are caused by sunlight shining through
ice crystals
in high clouds. Even during a warm New Zealand summer, these crystals
are present; it's always freezing cold 5 to 10 km above the ground
where cirrus clouds float in front of the sun.
So, no matter where you live, no matter what the season, be alert
for sundogs, furry and icy. You might find more than you
bargained for....
more images: from
Rob Kleeman of Niles, Illinois; from
Ken Scott on the shore of Lake Michigan; from
Andrew Shaidurov at the Bukovel ski resort in the Ukraine; from
Cheryl Heassig of Waukesha, Wisconsin; from
Monika Landy-Gyebnar of Veszprem, Hungary
February
2009 Aurora Gallery
[Previous Februaries: 2008,
2007,
2006,
2004,
2003,
2002]
Explore
the Sunspot Cycle
|
