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(meteorobs) A-T Campaign 96: Part 1
Part 1: The Discovery of the Aries-Triangulid Radiant
By Gary W. Kronk
The Aries-Triangulid radiant was discovered on the night of September 12,
1993 by ALPO and IMO member Gary W. Kronk (Troy, Illinois), Kurt Sleeter
(Swansea, Illinois), and ALPO and AMS member George Gliba (Greenbelt,
Maryland).
Kronk and Sleeter began observing together at 4:00 UT. Their intentions
were not to look for meteors, but to search for deep sky objects with a
13.1-inch and 10-inch reflectors, with the hope of observing numerous faint
objects listed in the Herschel catalog and determining their magnitudes.
The area being covered at the beginning of the session was the region
around Andromeda and Cassiopeia. Within 5 minutes of the beginning of the
session, each observer had already detected a meteor through their
telescopic field of views: Sleeter was observing in Cassiopeia and saw a
faint meteor heading northwestward, while Kronk was observing the
satellites of the Andromeda galaxy and saw a meteor heading westward. It
was decided to occasionally look at the sky during the brief periods of not
searching for deep sky objects.
By the time 5:15 UT had rolled around, Kronk and Sleeter had recorded a
total of 15 meteors during occasional meteor watching within the 1 hour and
15 minute session. From their brief descriptions, it seemed obvious that 11
meteors had radiated out of the Aries-Triangulum region. One 3rd-magnitude
meteor that had passed 41 Arietis was plotted by Sleeter on the only chart
they had available--Uranometria 2000.0 : Volume I (chart 130). The last
meteor detected was one of the brighter ones seen at magnitude 2. It was
short-trailed (about one degree long) and seemed to have began at Gamma
Arietis and traveled away from that star seemingly on the line connecting
Gamma and Beta Arietis. It was immediately plotted by Kronk on Uranometria
2000.0 chart 129.
Beginning at 5:15 UT, Kronk and Sleeter grabbed a pair of lawn chairs and
began looking exclusively for meteors. During the course of the next hour,
they were severely hampered by clouds for half the time, but still observed
5 meteors, of which 1 was a Piscid and 3 were from the Aries-Triangulum
region. All three of the meteors from the latter radiant were short-trailed
and were plotted by Sleeter, based on the observations of Kronk and
himself.
Kronk and Sleeter ended their session at 6:15 UT. Kronk visually estimated
the radiant as a little south of Alpha Triangulii, and came up with a
radiant estimate of RA=35 degrees, DEC=+30 degrees. Sleeter extended the
plotted meteors backward and found they all met very close to RA=30
degrees, DEC=+30 degrees. Except for a few exceptions, the meteors were
described as faint, with magnitudes typically between 3 and 5.
George Gliba was unaware of what the midwestern observers had seen when he
began his meteor observing session near Mathias, West Virginia, at the
private observing site of the Westminster Astronomical Society of Maryland.
His session began at 5:18 UT after extensive deep-sky observing. For the
next two hours, with very clear skies, he counted 35 meteors, but was
struck by the fact that 11 had radiated out of the Aries region. Although
he saw one of magnitude -2 and another of magnitude 1, all the other
meteors from this region were between magnitudes 3 and 5. He estimated the
radiant was near Gamma Arietis, indicating a position of RA=28 degrees,
DEC=+19 degrees. Gliba later admitted that, because of his orientation, the
meteor distribution made his right ascension more accurate than his
declination. He also noted the radiant seemed diffuse and that the position
could easily be moved as much as 5° in any direction.
Both Kronk and Gliba independently e-mailed several people on the internet
asking for any confirmation. Fortunately, one person contacted by both
observers was Peter Brown, the Coordinator of the North American branch of
the International Meteor Organization. Since Gliba had beat Kronk in
writing to Brown, Brown quickly acknowledged Kronk's e-mail with the news
that Gliba had seen activity from the same region of the sky.
Kronk continued to pursue the matter after getting details from Gliba and
approached several European observers. Although there was no obvious
confirmation of activity, Kronk later learned that during the period of
0:00 to 2:00 UT on September 12, Maurice De Meyere (Deurle, Belgium) was
operating a forward scatter radio meteor detector and registered enhanced
activity that was 17% to 83% higher than during the same hours on all other
dates during the period of September 1 to 15. Although it connot be
absolutely said that this activity belonged to the same radiant seen by
Gliba, Kronk, and Sleeter, the fact that enhanced activity was detected
during the early hours of the 12th in Belgium, West Virginia, and Illinois
was certainly suspicious.
The next installment will be Part 2: Search for Historical Data