February is the only month of the year that sees a fall in rates in both
hemispheres. As seen from the northern hemisphere, sporadic rates continue
the fall that began in January. This will continue until June when rates
reach their nadir. After a brief peak of activity in January, sporadic rates
in the southern hemisphere also slide downward until March. Shower activity
is low this month but decidedly more interesting in the southern hemisphere.
During February there are several sources of activity in the southern
morning sky. Most notable is the Alpha Centaurids, which are active during
the entire month of February. Other sources are scattered from Carina
through Puppis, Vela, and on into Centaurus and Lupus. None of these even
rate as a minor shower but together, along with the Alpha Centaurids, create
some interesting viewing during the summer nights south of the equator. Only
a trace of this activity can be seen from the northern tropics. The
Antihelion radiant remains north of the celestial equator and produces a
modest 1-2 meteors per hour from Leo. The weak Delta Leonids become active
at mid-month but are few and far between, even at maximum activity.
During this period the moon reaches its full phase on Monday February 9. At
this time the moon will rise near sundown and will remain in the sky all
night long. As the week progresses the moon will rise later in the evening
giving a growing window of darkness just after evening twilight. The more
active morning hours will still suffer from the intense moonlight. The
estimated total hourly rates for evening observers this week is near one no
matter your location. For morning observers the estimated total hourly rates
should be near five for those located in the mid-northern hemisphere (45 N)
and six for those viewing from the mid-southern hemisphere (45 S). These
rates assume that you are watching from rural areas away from all sources of
light pollution. The actual rates will also depend on factors such as
personal light and motion perception, local weather conditions, alertness
and experience in watching meteor activity. Rates are reduced this week due
to intense moonlight.
The radiant positions and rates listed below are exact for Saturday
night/Sunday morning February 7/8. These positions do not change greatly day
to day so the listed coordinates may be used during this entire period. Most
star atlases (available at science stores and planetariums) will provide
maps with grid lines of the celestial coordinates so that you may find out
exactly where these positions are located in the sky. A planisphere or
computer planetarium program is also useful in showing the sky at any time
of night on any date of the year. Activity from each radiant is best seen
when it is positioned highest in the sky, either due north or south along
the meridian, depending on your latitude. It must be remembered that meteor
activity is rarely seen at the radiant position. Rather they shoot outwards
from the radiant so it is best to center your field of view so that the
radiant lies at the edge and not the center. Viewing there will allow you to
easily trace the path of each meteor back to the radiant (if it is a shower
member) or in another direction if it is a sporadic. Meteor activity is not
seen from radiants that are located below the horizon. The positions below
are listed in a west to east manner in order of right ascension (celestial
longitude). The positions listed first are located further west therefore
are accessible earlier in the night while those listed further down the list
rise later in the night.
The full descriptions of each active meteor shower will continue next week
when the moon becomes less of a nuisance to observers.
The list below presents a summary of the expected activity this week. Rates
and positions are exact for Saturday night/Sunday morning but may be used
all week.
Antihelion (ANT) - 10:08 (152) +09 Velocity - 30km/sec.
Hourly Rates - Northern Hemisphere - 1 Southern Hemisphere - 1
Alpha Centaurids (ACE) 14:08 (212) -59 Velocity - 56km/sec.
Hourly Rates - Northern Hemisphere - <1 Southern Hemisphere - 3
Clear Skies!
Robert Lunsford
International Meteor Organization |
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