[Prev][Next][Index][Thread]
(meteorobs) 1997 NAMN Minor Shower Calendar
*********************************************
***** North American Meteor Network *****
***** 1997 Meteor Shower Calendar *****
***** Minor Shower Highlights *****
*********************************************
What follows is the calendar of NAMN minor shower targets for the upcoming
year. These showers are highlighted for 1997 because of their need for many
additional observations. These showers are best observed by experienced
observers using plotting techniques. For information on the technique of
plotting meteors, observers are encouraged to obtain a copy of the NAMN
Guide from the Coordinator.
I would like to thank Gary Kronk, Director, NAMN Minor Shower Section, who
compiled the following calendar.
-Mark Davis
NAMN Coordinator
-------------------------------------------------------------------------
JANUARY BOOTIDS
Radiant: RA=226 degrees (15 hours 04 minutes), DEC=+44 degrees
Observations of this radiant extend all the way back to the 1870s, but it
has never been fully studied. Since 1937 there have only been a handful of
visual observations, and the existence of only one photographic meteor
orbit did not inspire further observations. The modern study of this stream
began in 1958, when it was observed with the radio telescope at Jodrell
Bank during January 11 to 25, with a peak on January 18. A radiant was
determined at the time of maximum. Interestingly, eight radar stations in
Russia detected enhanced meteor activity on January 15-16 of that year, but
no radiant was determined. The radiant was again detected during the 1969
session of the Radio Meteor Project. The duration of activity covers the
period of January 9-18, with maximum falling sometime between January 16-18
in 1997. Full moon on the 23rd will not greatly interfer with observations
of the radiant which reaches the zenith at about 6:40 a.m.
AURIGIDS
Radiant: RA=74 degrees (4 hours 56 minutes), DEC=+42 degrees
Occasionally referred to as the Alpha Aurigids. This minor meteor shower
seems to have been observed quite often during the late 19th and early 20th
centuries, with famous British amateur astronomer William F. Denning and
other observers noting it was rich in bright fireballs; however, it is
frequently ignored nowadays. It is uncertain whether this indicates
activity from the radiant is waning or not. Based on only a handful of
observations since 1970, hourly rates seem to reach a maximum of only 1 or
2 per hour, although the Western Australia Meteor Section found a ZHR of
7.3 during February 2-7, 1980. There is only one photographic meteor orbit
available for this radiant and no radio-echo orbits, so the stream's orbit
is very poorly known. The radiant's duration extends from January 31 to
February 23, with maximum occurring sometime between February 4 and 10. A
February 7 new moon will favor observations in 1997, with the radiant at
the zenith around 8 p.m. (local time).
XI DRACONIDS
Radiant: RA=280 degrees (18 hours 40 minutes), DEC=+54 degrees
This radiant was discovered in 1996 by six individuals in the United States
and Europe, including two NAMN members. The observations were made between
June 12 and 18. Research has revealed no trace of the radiant prior to
1931, but 10 visual radiants, possibly as many as 19 photographic meteor
orbits, and 11 radio-echo meteor orbits since 1931. Especially notable are
the three visual radiants detected during 1931 from Europe and the United
States. The duration seems to extend from June 2 to 23, but despite all of
the data, the maximum can not be pinpointed any better than Solar longitude
81 to 85 degrees, which will occur within the period of June 12 to 16 in
1997. Although the radiant is circumpolar, it will pass through the zenith
around midnight. The moon will be full on June 20, so morning observations
around the time of maximum are favored. This radiant desparately needs more
observations.
ARIES-TRIANGULIDS
Radiant: RA=31 degrees (2 hours 04 minutes), DEC=+30 degrees
This radiant was discovered on September 12, 1993 by three individuals in
the United States and a possible fourth in Europe. The radiant appears to
have a rather rich history, with 20 radiants plotted during the period of
1915 to 1967, yet no one ever recognized it as a returning radiant. In
addition, a search through a database of over 39000 radio-echo meteor
orbits revealed 47 likely members of this stream, so the orbit is well
determined. Interestingly, independent observations were made by two
individuals during 1934, 1940, and 1951. These observations, as well as the
1993 observations, could indicate the activity is periodic, with a likely
period of 5.5 to 6 years. The actual name of this radiant has still not
been decided upon, although it is becoming clear that there are two
possible radiants: a strong one near Alpha Triangulii, and a weak one in
Aries. The duration of the activity may extend from September 5 to 15, and
in 1997 the probable date of maximum comes on the night of September 12. A
full moon on the 16th will cause some problems, but morning observations of
this radiant are possible. The radiant reaches the zenith after 2 a.m.
OCTOBER CETIDS
Radiant: RA=16 degrees (1 hours 04 minutes), DEC=+2 degrees
Traces of this radiant are found in the visual records as early as 1916 and
1917. The orbit is very well defined using 70 meteors from both the
photographic and radio-echo database, but it is still frequently ignored by
observers. Both northern and southern branches are indicated, with the
northern being the strongest. The duration of activity may extend from
September 8 to October 30, with probable maximums coming on October 8 for
the southern radiant and October 10 for the northern. The radiant may be
especially important because its orbit is similar to the lost Apollo
asteroid Hermes, which made a very close approach to Earth in 1937. Full
moon occurs on October 16 in 1997, so observations during the period of
maximum activity seem favorable with the radiant transitting around
midnight.
<END OF CATALOG>