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(meteorobs) Kind of a mini Radiant-Rising
The AURIGIDS, A NEW MOON, AND LABOR DAY
This holiday weekend in the US brings the two most
active showers of the month to the early morning sky.
The alpha-Aurigids (AUR) have a narrow peak (ZHR=~10)
at about O hours UT on September 1st. Rates are in the
visual range (ZHR>3) for three nights either side of that,
and exceed 1 per hour through Sept 5th, suitable for plotting.
The delta-Aurigids (DAU), which are actually in
Perseus at the peak on the 9th, have lower rates. In fact
ALPO refers to this shower as the September Perseids.
The peak rate is about ZHR=6, with the official start of
the shower at the time the alpha-Aurigids end on the 5th.
However the IMO record of observations since
1988 suggest that it may be visible earlier; if one
assumes that the rise and fall of rates is symmetrical
visual detection should be possible by Sept 1st or earlier
and should continue to nearly the end of the month,
with detection by plotting continuing through the
official end of the shower Oct 10th.
Since Auriga and Perseus rise after midnight
for North America, these are not going to be seen in the evening.
As with all minor showers, plotting is the best way
to accuratly identify these shower's meteors, and even then
some care must be taken to separate them. A field of view in
Taurus or Cepheus gives the best chance to differentiate between
the two, since both have similar velocities; 66 kph for the AUR's
and 64 for the DAU's. Both radiants are on Atlas BRNO charts
# 1 and 7, other maps that may be needed for plotting include
2,3,4 and 6. Limiting magnitude areas that are nearby include
#7 in Cepheus, #18 in Taurus, #2 in Perseus, and #17 in Auriga.
Here are the radiant positions for some of the dates. RA is
given in degrees, then Hours and minutes, and of course Declination
is in degrees. By the way the dates given refer to the morning hours,
since by the time we observe here in North Amereica,
it's the next day in UT
alpha-Aurigids (AUR) delta-Aurigids (DAU)
ZHR 10 Velocity 66kps ZHR 6 Velocity 64kps
r=2.5 r=3.0
Date RA Dec RA Dec
Aug 30 082 (5H 27m) +42 050 (3H 20m) +46 tonight
Sept 1 084 (5H 35m) +42 052 (3H 28m) +46 AUR peak
Sept 5 088 (5H 54m) +42 056 (3H 44m) +47 AUR/DAU vis
Sept 9 094 (6H 11m) +42 060 (4H 00m) +47 DAU peak
Sept14 098 (6H 33m) +42 065 (4H 20m) +48 last night before full moon
Much more information is needed on these two showers, and with the new moon,
along with an extra weekend day, this is a great chance to collect lots
of data. Clear skies to you all, and stay up late!
Coming up next week....another possible shower needing more data;
the Arietids-Triangulids
Wayne