Local Astronomical Info

Current Local Time: Thursday, November 2, 2006 2:14:02 am CST

Julian Date: 41.

Local Sidereal Time: 02:45:52.1

This page provides automatically generated astronomical information for the Saint Cloud, MN area[1] as well as links to astronomical information on other websites that can help you decide whether the conditions to make astronomical observations tonight.

Meteor Activity Outlook for October 27 - November 2, 2006

Meteor rates continue to be strong as seen from the northern hemisphere. The antihelion radiant has now merged with the two Taurid radiants producing slow meteors during the late evening and early morning hours. Meteors from the Orionid radiant are visible most of the month. Strong sporadic rates continue during the morning hours as long as the moon is below the horizon. From the southern hemisphere, sporadic rates have reached their nadir and begin a slow recovery the second half of the month. Meteors from the Taurid and Orionid radiants also help to fill the southern skies with more activity than has been seen since July. A new moon during the peak of the Orionid shower is a plus for all and should help inflate meteor totals that have suffered since the Perseid maximum back in August. This week the moon reaches its first quarter phase on Sunday October 29. At this time the moon will set near midnight local standard time (LST) and will not be a factor in observing during the busy morning hours.

The estimated total hourly rates for evening observers this week is near four for those north of the equator and two for observers south of the equator. For morning observers the estimated total hourly rates should be near thirty for northern observers and twenty for those south of the equator. 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 October 28/29.

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 showers are expected to be active this week: At this time of year debris from comet 2P/Encke produces a double radiant very close to the position of the antihelion radiant. From now through the end of November, it is impossible to resolve the antihelion meteors from those produced by comet 2P/Encke. Therefore we suggest that observers simply classify meteors from this area as either north or south Taurids.

Although the radiants actually lie in Aries during October, they reach maximum activity in November when they are situated in the constellation of Taurus. The Northern Taurid (NTA) radiant is now centered at 03:04 (046) +20. This position lies in eastern Aries, two degrees west of the fourth magnitude star Delta Arietis. The Southern Taurid (STA) radiant lies at 03:04 (046) +14. This position lies in southeastern Aries, five degrees southwest of Delta Arietis. The two radiants are separated by slightly over five degrees. Since they have the same right ascension (celestial longitude), it is difficult to distinguish meteors that move north or south out of the radiants.

It is slightly less difficult to distinguish those meteors traveling east or west. These radiants are above the horizon most of the night and are best placed near midnight LST, when they lie on the meridian and are located highest in the sky. Rates at this time should be near three per hour for the southern radiant and two per hour for the northern radiant, regardless of your location. With an entry velocity near 30 km/sec., the average Taurid meteor would be of medium-slow speed. The Orionids (ORI) put on a fantastic display this past weekend. Rates were three times than what were expected. Rates are still above normal at around 10-15 per hour. The radiant has now moved into the constellation of Gemini and is located at 06:40 (100) +16.

This position lies in southwestern Gemini, at the spot occupied by the second magnitude star Alhena (Gamma Geminorum). The radiant rises near 2100 LST and is best placed on the meridian near 0400. Rates will slowly diminish as we move further away from the date of maximum activity. At 64km/sec., the average Orionid is swift. Sirko Molau's study of video radiants has revealed activity from the Gemini/Cancer border during the period October 27 through November 4. Maximum occurs on October 31 with a radiant located at 07:44 (121) +16. This position lies in western Cancer, three degrees southwest of the faint star known as Zeta Cancri. This radiant is best placed on the meridian near 0500 LST.

It appears that six percent of the total activity for the night is related to this radiant. At 60km/sec., the average meteor from this radiant would be swift. Sporadic rates have reached the late year plateau for observers located in the northern hemisphere. One would expect to see perhaps sixteen random meteors during the last hour before dawn from rural observing sites. During the first dark hour after the end of evening twilight, perhaps four random meteors can be seen per hour. Sporadic rates increase as the night progresses so rates seen near midnight would be near ten per hour. Sporadic rates seen from the southern hemisphere have passed their annual minimum and are rising again.

One would expect to see approximately five random meteors per hour during the last hour before dawn and two per hour during the first dark hour after the end of evening twilight. Rates near midnight would be near four per hour. SHOWER DATE OF MAXIMUM ACTIVITY CELESTIAL POSITION ENTRY VELOCITY CULMINATION HOURLY RATE CLASS* RA (RA in Deg.) DEC Km/Sec Local Standard Time North-South Northern Taurid (NTA) Nov 12 03:04 (046) +20 29 00:00 2 – 2 II Southern Taurid (STA) Nov 5 03:04 (046) +14 27 00:00 3 – 3 II Orionids (ORI) Oct 21 06:40 (100) +16 66 04:00 10 – 10 I Zeta Cancrids (ZCA) Oct 31 07:44 (121) +16 60 05:00 2 – 2 IV

Maximum Distance from the Sun

• Mercury()
  43.4 million miles

  Venus()
  68 million miles

• Earth()
  94.5 million miles

  Mars()
  155 million miles

• Jupiter()
  508 million miles

  Saturn ()
  938 million miles

• Uranus()
  1.87 billion miles

  Neptune()
  2.82 billion miles