Meteor Activity Outlook for 18-24 November 2023

Boris Häußler captured this bright fireball on June 22, 2023, at 05:14 UT from Antofagasta, Chile. He mentioned that the persistent train lasted an incredible 20-30 minutes! ©Boris Häußler

During this period, the moon reaches its first quarter phase on Monday November 20th. On that night the half-illuminated moon will be located 90 degrees east of the sun and will set near 23:00 local standard time (LST). As the week progresses, the waxing gibbous moon will set later in the morning hours, shrinking the window of opportunity to view under dark skies. The estimated total hourly rates for evening observers this weekend should be near 4 as seen from mid-northern latitudes (45N) and 3 as seen from tropical southern locations (25S) For morning observers, the estimated total hourly rates should be near 22 as seen from mid-northern latitudes (45N) and 13 as seen from tropical southern locations (25S). Evening rates are reduced due to moonlight. The actual rates seen will also depend on factors such as personal light and motion perception, local weather conditions, alertness, and experience in watching meteor activity. Note that the hourly rates listed below are estimates as viewed from dark sky sites away from urban light sources. Observers viewing from urban areas will see less activity as only the brighter meteors will be visible from such locations.

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 November 18/19. 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. I have also included charts of the sky that display the radiant positions for evening, midnight, and morning. The center of each chart is the sky directly overhead at the appropriate hour. These charts are oriented for facing south but can be used for any direction by rotating the charts to the desired direction. 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. Radiants that rise after midnight will not reach their highest point in the sky until daylight. For these radiants, it is best to view them during the last few hours before dawn. It must be remembered that meteor activity is rarely seen at its radiant position. Rather they shoot outwards from the radiant, so it is best to center your field of view so that the radiant lies toward 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 sporadic. Meteor activity is not seen from radiants that are located far 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 sources of meteoric activity are expected to be active this week

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The last of the Southern Taurids (002 STA) are expected this weekend from a radiant located at 04:12 (063) +16. This position lies in central Taurus, 1 degree northwest of the 4th magnitude star known as Prima Hyadum (gamma Tauri A). To best see these meteors, one should face southward near 01:00. Rates at this time should be near 1 per hour from the northern hemisphere and less than 1per hour from south of the equator. With an entry velocity of 27 km/sec., the average STA meteor would be of medium-slow velocity.

The Northern Taurids (017 NTA) are active from a radiant located at 04:17 (064) +24. This area of the sky is located in northwestern Taurus, 5 degrees east of the Pleiades. Like the STA’s, to best see these meteors, one should face southward near 01:00. Maximum activity was on November 12^th so rates at this time should be near 2 per hour as seen from the northern hemisphere and 1 as seen from south of the equator. With an entry velocity of 29 km/sec., the average NTA meteor would be of medium-slow velocity.

The November Orionids (250 NOO) are active from November 13 through December 12, with maximum activity occurring on November 30^th. The radiant is currently located at 05:34 (083) +16. This area of the sky lies on the Orion/Taurus border, 6 degrees north of the 4th magnitude star known as Meissa (lambda Orionis A). This radiant is best placed in the southern sky near 0200 LST, when it lies highest above the  horizon. Rates should be near 2 per hour as seen from the northern hemisphere and 1 as seen from south of the equator. With an entry velocity of 44 km/sec., most activity from this radiant would be of medium speed.

The alpha Monocerotids (246 AMO) are best known for their occasional outbursts, the last which occurred in 2019. These meteors are active from November 13-27 with maximum occurring on the 22nd. Rates away from the night of maximum are very low, far less than 1 per hour no matter your location. The radiant is currently located at 07:43 (116) +01. This area of the sky is located in southern Canis Minor, 4 degrees south of the zero-magnitude star known as Procyon (alpha Canis Minoris A). To best see these meteors, face toward the south during the last hours prior to dawn. With an entry velocity of 65km/sec, most of these meteors would appear to be swift.

The Leonids (013 LEO) are active from November 3^rd to December 2nd with maximum activity occurring on November 18^th. The radiant is currently located at 10:19 (155) +21. This position lies in northwestern Leo, 3 degrees northwest of the 3rd magnitude double star known as Algieba (gamma Leonis A). The Leonid radiant is best placed in the southeastern sky during the last hour before morning twilight when the radiant lies highest in the northern sky. Leonids may be seen from the southern hemisphere, but the viewing conditions are not quite as favorable as those north of the equator. Current rates are expected to be near 5 per hour as seen from the northern hemisphere and 3 as seen from south of the equator. With an entry velocity of 71 km/sec., most activity from this radiant would be of swift speed with numerous persistent trains on the brighter meteors.

Sporadic meteors are those meteors that cannot be associated with any known meteor shower. All meteor showers are evolving and disperse over time to the point where they are no longer recognizable. Away from the peaks of the major annual showers, these sporadic meteors make up the bulk of the activity seen each night. As seen from the mid-Northern Hemisphere (45N) one would expect to see during this period approximately 12 sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near 2 per hour. As seen from the tropical Southern latitudes (25S), morning rates would be near 8 per hour as seen from rural observing sites and 1 per hour during the evening hours. Locations between these two extremes would see activity between these listed figures.

The list below offers the information in tabular form. Rates and positions are exact for Saturday night/Sunday morning.

Class Explanation: A scale to group meteor showers by their intensity:

• Class I: the strongest annual showers with Zenith Hourly Rates normally ten or better.
• Class II: reliable minor showers with ZHR’s normally two to ten.
• Class III: showers that do not provide annual activity. These showers are rarely active yet have the potential to produce a major display on occasion.
• Class IV: weak minor showers with ZHR’s rarely exceeding two. The study of these showers is best left to experienced observers who use plotting and angular velocity estimates to determine shower association. These weak showers are also good targets for video and photographic work. Observers with less experience are urged to limit their shower associations to showers with a rating of I to III.