Meteor Activity Outlook for November 7-13, 2009

As seen from the northern hemisphere, meteor rates continue to be strong in November. While no major showers are active this month, the two Taurid radiants plus the Leonids keep the skies active. The addition of strong sporadic rates make November one of the better months to view meteor activity from north of the equator. Skies are fairly quiet as seen from the southern hemisphere this month. Activity from the three showers mentioned above may be seen from south of the equator, but the sporadic rates are much lower than those seen in the northern hemisphere.

During this period the moon reaches its last quarter phase on Monday November 9th. On that date the moon lies ninety degrees west of the sun and rises near midnight local standard time (LST). While not the most favorable conditions, successful meteor observations can be undertaken at this time if one keeps the moon out of your field of view. Conditions improve with each passing night this week as the moon wanes and rises later each morning. The estimated total hourly rates for evening observers this week is near four as seen from the northern hemisphere and two from the southern hemisphere. For morning observers the estimated total hourly rates should be near fifteen from the northern hemisphere and eight as seen from the southern hemisphere. 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 by moonlight during the morning hours during this period.

The radiant positions and rates listed below are exact for Saturday night/Sunday morning November 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 following showers are expected to be active this week:

Sirko Molau's studies of video radiants has revealed that activity from the famous Andromedid shower, noted for intense storms during the 19th century, may still be seen throughout November. The current position of the large radiant is 01:27 (022) +27. This position lies in a spase area of northeastern Pisces. The nearest bright star star is third magnitude Alpha Trianguli, which lies five degrees to the northeast. Visual activity is expected to be low, but detectable. The Andromedid radiant is best placed near 2200 (10pm) LST when it lies on the meridian. At 20km/sec., the average Andromedid will appear as a very slow moving meteor. Sirko mentions that these meteors are "conspicuously slow and of almost constant activity" during this period.

The Northern Taurids (NTA) are active from a large radiant centered at 03:42 (056) +22, which lies in western Taurus, three degrees southwest of the famous naked eye star cluster known as the Pleiades. The radiant is best placed near 0100 LST, when it lies highest above the horizon, but activity may be seen all night long. Meteors from the Northern Taurids strike the atmosphere at 29km/sec., which would produce meteors of slow velocity. Expected rates would be near three per hour as seen from the northern hemisphere and two per hour as seen south of the equator.

The center of the large Southern Taurid (STA) radiant lies at 03:45 (056) +14. This position lies in western Taurus, ten degrees south of the famous naked eye star cluster known as the Pleiades. The radiant is best placed near 0100 LST, when it lies highest above the horizon, but activity may be seen all night long. Striking the atmosphere at 29 km/sec., the average Southern Taurid meteor travels slowly through the skies. Rates should be near two per hour no matter your location.

The Orionids (ORI) reached maximum activity on the nights of October 21 and 22. Rates have fallen since then and will do so until the last Orionids are seen near November 14. The radiant is currently located at 07:17 (109) +16. This position lies in southern Gemini very close to the fourth magnitude star Lambda Geminorum. The radiant is best placed near 0500 LST, when it lies highest above the horizon. Current rates would be less than one per hour. At 66km/sec., the average Orionid is swift.

The Leonids (LEO) are just now coming to life from a radiant located at 09:52 (148) +25. This position lies in western Leo, very close to the position of the faint star 22 Leonis. Maximum activity is still more than a week away so current rates would most likely be less than one per hour. At 70km/sec., the average Leonid is swift with a high percentage of trains. The radiant is most favorably located during the last dark hour before the onset of morning twilight.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately ten Sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near three per hour. As seen from the mid-southern hemisphere (45S), morning rates would be near four per hour as seen from rural observing sites and one per hour during the evening hours. Locations between these two extremes would see activity between the listed figures. Sporadic rates seen during the morning hours are reduced during this period due to moonlight.

The table below presents a condensed version of the expected activity this week. Rates and positions are exact for Saturday night/Sunday morning but may be used all week long.

Andromedids (AND) - 01:27 (022) +27 Velocity - 19km/sec. Northern Hemisphere - <1 per hr. Southern Hemisphere - <1 per hr.

Northern Taurids (NTA) - 03:42 (056) +22 Velocity - 29km/sec. Northern Hemisphere - 2 per hr. Southern Hemisphere - 3 per hr.

Southern Taurids (STA) - 03:45 (056) +14 Velocity - 29km/sec. Northern Hemisphere - 2 per hr. Southern Hemisphere - 2 per hr.

Orionids (ORI) - 07:17 (109) +16 Velocity - 67km/sec. Northern Hemisphere - <1 per hr. Southern Hemisphere - <1 per hr.

Leonids (LEO) - 09:52 (148) +25 Velocity - 70km/sec. Northern Hemisphere - <1 per hr. Southern Hemisphere - <1 per hr.