During this period the moon reaches its full phase on Tuesday May 17. At this time the moon will lie opposite the sun and will be in the sky all night long. This is the worst time of the month to try and view meteor activity as the bright moonlight will obscure all but the brightest meteors. The estimated total hourly rates for evening observers this week is near one as seen from the northern hemisphere and two as seen from the southern hemisphere. For morning observers the estimated total hourly rates should be near five from the northern hemisphere and nine as seen from south of the equator. 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 moonlight.
The radiant (the area of the sky where meteors appear
to shoot from) positions and rates listed below are exact for Saturday night/Sunday
morning May 14/15. 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 following showers are expected to be active this week. Details concerning each shower will continue next week when the moon will be in a more favorable position.
SHOWER | DATE OF MAXIMUM ACTIVITY | CELESTIAL POSITION | ENTRY VELOCITY | CULMINATION | HOURLY RATE | CLASS* |
RA (RA in Deg.) DEC | Km/Sec | Local Daylight Time | North-South | |||
Antihelion (ANT) | – | 16:28 (247) -22 | 30 | 02:00 | 1 – 2 | II |
Eta Aquariids (ETA) | May 07 | 22:56 (344) +02 | 67 | 09:00 | 1 – 3 | I |