http://www.skyandtelescope.com.au 47by Con Stoitsis METEORSSuper summer showers
Get ready for the Leonids and Geminids show.
T
wo of my favourite meteor
showersreturninNovemberand
December. The last perihelion
passageoftheLeonids’parentcomet,
55P/ Tempel-Tut t le, in 1998 is almost
twodecadesagonow.Ourknowledge
of the comet’s dust ejection and trail
evolutionhasgreatlyimprovedsince
then,duemainlytotheworkofMikhail
Maslov.Accordingtohiscalculations
thereisachanceforarathernarrow
trailofmeteoroidstobereleasedfromNOVEMBER
2 Venus4°northofSpica
3 Uranus4°northofMoon
6 Aldebaran0.8°southofMoon
12 Regulus0.4°southofMoon
13 Venus 0.3° north of Jupiter
15 Mars 3° south of Moon
17 Jupiter4°southofMoon
20 Mercury7°southofMoon
21 Saturn3°southofMoon
24 Mercurygreatestelong.east(22°)
28 Mars 3° north of Spica
28 Mercury 3° south of SaturnNOVEMBER
Full Moon ...... 4th, 05:23 UT
LastQuarter......10th,20:36UT
New Moon ...... 18th, 11:42 UT
First Quarter ...... 26th, 17:03 UT
Perigee ...... 6th, 00h UT, 361,438 km
Apogee ...... 21st, 19h UT, 406,132 km
DECEMBER
Full Moon ...... 3rd, 15:47 UT
Last Quarter ...... 10th, 07:51 UT
New Moon ...... 18th, 06:30 UT
First Quarter ...... 26th, 09:20 UT
Perigee ...... 4th, 09h UT, 357,492 km
Apogee ...... 19th, 01h UT, 406,603 kmSKY PHENOMENA(dates in AEST) LUNAR PHENOMENA
DECEMBER
3 Mercury stationary
3 Aldebaran 0.8° south of Moon
9 Regulus0.7°southofMoon
13 Mercuryininferiorconjunction
14 Mars4°southofMoon
15 Jupiter 4° south of Moon
22 Solstice
22 Saturn in conjunction with Sun
23 Mercury stationary
24 Neptune1.4°northofMoon
28 Uranus5°northofMoon
31 Aldebaran 0.8° south of MoonThe Geminids is the best and the
most reliable meteor shower of the year,
this year reaching its broad maximum
on December 14 at 06:30 UT. From
the Southern Hemisphere the radiant
appears around local midnight or so;
it is best placed after 3:00am local
time. There will be plenty of activity,
with a splendid stream of often-bright,
medium-speed meteors.
Rates of 40 to 60 meteors per hour
are predicted for the morning of thethe parent comet, reaching Earth on
November 16 at 17:07 universal time
(UT), with a zenithal hourly rate (ZHR)
of about 10 to 12, composed of brighter
meteors. The traditional maximum
should occur on November 17 near
16:30 UT, also with a ZHR of 10 to 12.
For Australian observers the radiant
will be best placed after 3:00am, low
in the northeast. It’ll probably be best
to observe on the mornings of the 17th
and 18th after 3.30am local time.
15th for those with dark
skies. From town it will
be closer to 12 to 18 per
hour. Mass-sorting within
the meteoroid stream
means fainter meteors
should be abundant
almost a day ahead and
after the maximum. Start
observing on the morning
of the 13th, and finish on
the morning of the 15th.■ CON STOITSIS
is director of the
Astronomical Society
of Victoria’s comet and
meteor sections.