(meteorobs) Meteor Activity Outlook for January 28-February 3, 2005

[Robert Lunsford]

This upcoming period will see the moon reaching its last quarter phase on
Wednesday February 2.  At this time the moon will rise near midnight and
cause some interference during the prime morning observing hours. The
estimated total hourly rates for evening observers this week should be near
two for those in the Northern Hemisphere and three for those observers south
of the equator. For morning observers the estimated total hourly rates
should be near seven for those located in the Northern Hemisphere and twelve
for those in the Southern Hemisphere. Rates are reduced during the morning
due to moonlight. 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.

The radiant positions listed below are exact for Saturday night/Sunday
morning January 29/30. 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. 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.

These are the showers that may be observed this week:

The Alpha Carinids (ACN) is a shower listed among radiants of the Dutch
Meteor Society. The date of maximum activity is January 30 with a predicted
ZHR of two. With such low activity care must be taken to exclude any
sporadic activity from the Alpha Carinid count. The radiant currently lies
at 06:20 (095) -54. This position lies in western Carina, only one degree
south of the brilliant negative one magnitude star Canopus (Alpha Carinae).
This radiant is only seen well from the northern equatorial regions
southward. The area of the sky is also best placed near 2200 (10pm) local
standard time. At 25 km/sec. the Alpha Carinids produce meteors of slow
velocity.

The Delta Velids (DVE) is another shower listed among radiants of the Dutch
Meteor Society. The date of maximum activity is February 14 with a predicted
ZHR of one. With such low activity care must again be taken to exclude any
sporadic activity from the Delta Velid count. The radiant currently lies at
08:16 (124) -57. This position lies in central Carina, two degrees north of
the second magnitude star Epsilon Carinae. This radiant is only seen well
from the northern equatorial regions southward. The area of the sky is also
best placed near midnight local standard time. At 35 km/sec. the Delta
Velids produce meteors of average velocity.

The Anthelion radiant is now centered at 09:36 (144) +14. This area of the
sky is located in western Leo, seven degrees northwest of the bright star
Regulus (Alpha Leonis). Since this radiant is large and diffuse, any slow to
medium speed meteor from northeastern northwestern Hydra, western Leo or
Cancer could be a candidate for this shower. The center of this area is best
placed near 0100 local standard time when it lies on the meridian and is
highest in the sky. At this time expect to see two shower members per hour
from the Northern Hemisphere and one per hour south of the equator.

Unlike most of the annual showers the antihelion source is produced by
debris from unknown objects orbiting in a direct motion like the earth.
These objects are most likely asteroids, which produce stony and metallic
debris whose density is much greater than material produced by comets. There
is also the possibility that some of this activity may be caused by the
"Jupiter family of comets", comets which have been altered by Jupiter's
gravity into much shorter orbits. This material collides with the earth on
the inbound portion of its orbit, before its closest approach to the sun.
Therefore we best see them just after midnight when we are facing the
direction from which this activity appears. The antihelion source is active
all year from an area of the sky nearly opposite that of the sun. The center
of this source will move approximately one degree eastward per day and
travels through many different constellations over the course of a year. It
may make sense to list these meteors as anthelions or "ANT" but a majority
of meteor organizations prefer that you list them from the constellation in
which the radiant is currently located or the constellation where the shower
reaches maximum activity. Observers who send their reports to the
International Meteor Organization (I.M.O.) should label these meteors as
Delta Cancrids (DCA).

The Alpha Hydrids (AHY) is another shower listed among radiants of the Dutch
Meteor Society. The date of maximum activity was January 14 with a predicted
ZHR of two. Current rates would be far less than one shower member per hour.
With such low activity care must be taken to exclude any sporadic activity
from the Alpha Hydrid count. The radiant currently lies at 09:36 (144) -16.
This position lies in western Hydra, five degrees southeast of the second
magnitude star Alphard (Alpha Hydrae). This radiant is seen equally
well from both hemispheres. The area of the sky is also best placed near
0200 local standard time. At 44 km/sec. the Alpha Hydrids produce meteors of
average velocity.

The Omicron Centaurids (OCE) are one of several radiants that are active in
Centaurus during late January and throughout the month of February. The date
of maximum activity is February 14 with a predicted ZHR of two. The radiant
lies at 10:52 (163) -50. This position is in eastern Vela, very close to the
third magnitude star Mu Velorum. Due to the southern declination this shower
is not well seen north of the northern tropical regions. This area of the
sky is best placed near 0300 local standard time when it lies highest in the
sky. At 51 km/sec. the Omicron Centaurids produce meteors of medium-swift
velocity.

The Theta Centaurids (TCE) is the first of several radiants that are active
in Centaurus during late January and throughout the month of February. The
date of maximum activity is February 14 with a predicted ZHR of four. The
radiant lies at 12:52 (193) -35. This position is in northwestern Centaurus,
five degrees northwest of the third magnitude star Iota Centauri. This
shower is not well seen north of the northern tropical regions. It is
possible to see activity from the latitude of San Diego, CA as I have
witnessed several of these meteors during my winter observations. This area
of the sky is best placed near 0500 local standard time when it lies highest
in the sky. At 60 km/sec. the Theta Centaurids produce meteors of swift
velocity.

The Alpha Centaurids (ACE) are the strongest of the radiants that are active
in Centaurus during late January and throughout the month of February. The
date of maximum activity is February 8 with a predicted ZHR of seven.
Current ZHR's would be near two. The radiant lies at 13:12 (198) -56. This
position is in southeastern Centaurus, six degrees northeast of the bright
fisrt magnitude star Beta Crux (Beta Crucis). Due to the southern
declination this shower is not well seen north of the northern equatorial
regions. This area of the sky is also best placed near 0500 local standard
time when it lies highest in the sky. At 56 km/sec. the Alpha Centaurids
produce meteors of swift velocity.

Possible activity in Bootes-Corona Borealis-Serpens Caput? There have been
reports of activity in and around this area in late January and early
February. Veteran observer George Gliba was the first to notice this
activity during the mid 90's. Intensified video studies by t he IMO in 2000
revealed two radiants; one in Serpens Caput and another located in Corona
Borealis during the first week of February. Observers are urged to keep a
look out for this activity now through mid-February. The two IMO radiants
are located at 15:32 (233) +30 and 15:44 (236) +13. The northern radiant is
located within the "crown" close to the star Beta Coronae Borealis. The more
southern radiant is located near the "head" of Serpens two degrees south of
Beta Serpentis. Another area of possible activity would lie in eastern
Bootes between Arcturus and Xi Bootis. This area of the sky is too low until
0200 local standard time. The waning moon will be a hindrance this week, but
will move out of the way from February 5 onwards.

Any suspected shower members would appear to move slowly if seen near the
radiant or near the horizon. Those seen high in the sky and far from the
radiant will appear to be swift. Meteors seen near the radiant would also be
short. If you are facing the radiants and see a long meteor close to the
radiant(s) then that meteors is sporadic or belongs to another shower.
Plotting, photographic and video observations are of prime importance to try
to help us determine shower association. Your efforts in trying to help us
verify this activity and its exact radiant would be extremely appreciated.

The Sporadic rates for the Northern Hemisphere are now past their annual
peak. One would expect to see perhaps four random meteors per hour during
the last hours before dawn from rural observing sites. During the evening
hours perhaps two random meteors can be seen per hour. Sporadic rates seen
from the Southern Hemisphere are increasing toward a peak this month. One
would see approximately six random meteors per hour during the late morning
hours and three per hour during the evening. Rates are reduced during the
morning due to moonlight

Alpha Carinids (ACN)   Radiant Position  = 06:20 (095)  -54
Hourly Rate = 0  N. Hemisphere, 1  S. Hemisphere

Delta Velids(DVE)   Radiant Position  = 08:16 (124)  -57
Hourly Rate = 0  N. Hemisphere, <1  S. Hemisphere

Anthelion        Radiant Position  = 09:36  (144) +14
Hourly Rate = 3  N. Hemisphere, 2  S. Hemisphere

Alpha Hydrids (AHY)   Radiant Position  = 09:36 (144)  -16
Hourly Rate = <1  N. Hemisphere, <1  S. Hemisphere

Omicron Centaurids (OCE)   Radiant Position  = 10:52 (163)  -50
Hourly Rate = 0  N. Hemisphere, <1  S. Hemisphere

Theta Centaurids (TCE)   Radiant Position  = 12:52 (193)  -35
Hourly Rate = <1  N. Hemisphere, 1  S. Hemisphere

Alpha Centaurids (ACE)   Radiant Position  = 13:12 (198)  -56
Hourly Rate = 0  N. Hemisphere, 2  S. Hemisphere


Clear Skies!
Robert Lunsford
American Meteor Society