Meteor Activity Outlook for December 21-27, 2024

Cullen Brown captured this bright Perseid fireball on August 12, 2024, at 01:16 CDT (06:16 UT) from Canyon Lake. Texas USA. At latitude 29 north latitude, sightings of aurora are very rare! ©Cullen Brown

During this period, the moon reaches its last quarter phase on Monday December 23th. At that time the moon will rise near midnight and will remain in the morning sky the remainder of the night. As the week progresses, the waning crescent moon will rise later in the morning offering a longer opportunity to view meteor activity 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 18 as seen from mid-northern latitudes (45N) and 9 as seen from tropical southern locations (25S). 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. Morning rates are reduced during this period due to moonlight. 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 December 21/22. These positions do not change greatly day to day so the listed coordinates may be used during this entire period. Most star atlases (available online and at bookstores 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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Now that the activity from particles produced by comet 2P/Encke have ceased encountering the Earth, the Taurid showers for 2024 are over and we resume reporting activity from the Anthelion (ANT) radiant. This is not a true radiant, but rather activity caused by the Earth’s motion through space. As the Earth revolves around the sun it encounters particles orbiting in a pro-grade motion that are approaching their perihelion point. They all appear to be radiating from an area near the opposition point of the sun, hence the name Anthelion. These were once recorded as separate showers throughout the year, but it is now suggested to bin them into a category separate from true showers and sporadics. This radiant is a very large oval some thirty degrees wide by fifteen degrees high. Activity from this radiant can appear from more than one constellation. The position listed here is for the center of the radiant which is currently located at 06:52 (103) +22. This position lies in central Gemini, 3 degrees southeast of the 3rd magnitude star known as Mebsuta (epsilon Geminorum). This radiant is best placed near 01:00 local standard time (LST) when it lies on the meridian and is highest in the southern sky. Rates at this time should be near 2 per hour as seen from the northern hemisphere and 1 per hour as seen from south of the equator. With an entry velocity of 30 km/sec., the average Anthelion meteor would be of slow velocity.

The Monocerotids (MON) are active from a radiant located at 07:15 (109) +06. This area of the sky is located in western Canis Minor, 3 degrees southwest of the 3rd magnitude star known as Gomeisa (beta Canis Minoris). This radiant best placed near 0100 LST, when it lies highest in the southern sky. Rates should be less than 1 per hour no matter your location. With an entry velocity of 39 km/sec., most activity from this radiant would be of medium speed. This shower is active from November 23^rd through December 24^th, with maximum activity occurring on December 11^th.

The sigma Hydrids (HYD) are active from a radiant located at 09:10 (137) -01. This area of the sky is located in western Hydra, 3 degrees southwest of the 4^th magnitude star known as theta hydrae. These meteors are active from November 24 through January 7^th, with the main maximum activity occurring on December 7^th. To best see these meteors, face toward the south during the last couple of hours prior to dawn. With an entry velocity of 58km/sec, most of these meteors would appear swift. Expect to see less than 1 per hour no matter your location.

The kappa Velids (KVE) were recently discovered by SAAMER (Pokorný et al., 2017), an Argentine meteor radar system. This radiant is the main radiant in an area where many minor radiants seem to be active this time of year. The KVE’s are active from December 16 through January 6 with maximum activity occurring on December 26th. The radiant is currently located at 09:15 (139) -49, which places it in central Vela, midway between the bright stars known as lambda and kappa Velorum. These meteors are best seen near 0300 LST when the radiant lies highest above the southern horizon. Current rates should be less than 1 per hour no matter your location. With an entry velocity of 43 km/sec., most activity from this radiant would be of medium speed.

The eta Hydrids (EHY) were recently discovered by members of the Croatian Meteor Network. This radiant is active from November 26 through January 1st with maximum activity occurring on December 12th. The radiant is currently located at 09:37 (144) -00, which places it in western Hydra, 1 degree northwest of the 4th magnitude star known as Ukdah (iota Hydrae). This position is close to that of the sigma Hydrids so care must be taken to separate the two sources. These meteors are best seen near 0400 LST when the radiant lies highest above the southern horizon. Current rates should be less than 1 per hour no matter your location. With an entry velocity of 62 km/sec., most activity from this radiant would be of swift speed.

The theta Pyxidids (TPY) consists of two weak showers that peak two weeks apart. The later version is active from December 8 through January 8, with maximum occurring on December 18th. The radiant is currently located at 10:35 (159) -25. This area of the sky is located in central Hydra, near the faint star known as 44 Hydrae. These meteors are best seen near 0500 LST when the radiant lies highest in the southern sky. Rates are expected to be less than 1 no matter your location. At 62 km/sec. the theta Pyxids would produce mostly swift meteors.

The Comae Berenicids (COM) are a long duration shower active from December 5th through February 4th. Maximum activity occurs on December 16th. The radiant is currently located at 10:56 (164) +29, which places it in southwestern Leo Minor, 5 degrees south of the 4^th magnitude star known as 48 Leonis Minoris. These meteors would be best seen near 05:00 LST, when the radiant lies highest in the eastern sky. Current rates should be near 2 per hour as seen from the northern hemisphere and near one as seen from south of the equator. At 63km/sec., these meteors would produce mostly swift meteors.

The December chi Virginids (XVI) was discovered by Japanese observers using data from SonotaCo. This source is active from November 26 through December 30 with maximum occurring on December 12^th. The radiant is currently located at 13:07 (197) -13, which places it in southern Virgo, 3 degrees southwest of the 1^st magnitude star known as Spica (alpha Virginis). Hourly rates should be less than 1 no matter your location. These meteors are best seen during the last dark hour before dawn, when the radiant lies highest above the southeastern horizon in a dark sky. At 69 km/sec. the December chi Virginids would produce mostly swift meteors.

The December rho Virginids (DRV) are active from November 29 through December 22 with peak rates occurring near December 5th. The current radiant location is at 13:25 (201) +11, which places it in northeastern Virgo, 4 degrees east of the 3^rd magnitude star known as Vindemiatrix (epsilon Virginis). Current hourly rates would be less than 1 no matter your location. These meteors are best seen during the last dark hour before dawn, when the radiant lies highest above the southeastern horizon in a dark sky. At 67 km/sec. the December rho Virginids would produce mostly swift meteors.

The December sigma Virginids (DSV) is a source of long duration discovered by John Greaves using the data from SonotaCo. This source is active from November 26 through January 24 with peak rates occuring near December 21st. The current radiant location is at 13:52 (208) +04, which places it in eastern Virgo, 3 degrees northeast of the 4th magnitude star known as tau Virginis. Current hourly rates would be less than 1 no matter your location. These meteors are best seen during the last dark hour before dawn, when the radiant lies highest above the southeastern horizon in a dark sky. At 66 km/sec. the December Sigma Virginids would produce mostly swift meteors.

The Ursids (URS) are active from a radiant located at 14:41 (220) +75. This area of the sky is located in southern Ursa Minor, 2 degrees northwest of the 2nd magnitude star known as Kochab (beta Ursae Minoris). The Ursids are active from December 13-24, with maximum activity occurring on the 22^nd. Current rates are expected to be near per hour, decreasing rapidly to less than 1 per hour after December 22nd. These meteors are best seen in the last few hours before dawn when the radiant lies highest in the northern sky. At 33km/sec., these meteors are of medium velocity. Due to the high northern location, these meteors are not visible from the southern hemisphere.

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 9 sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near 3 per hour. As seen from the tropical Southern latitudes (25S), morning rates would be near 7 per hour as seen from rural observing sites and 2 per hour during the evening hours. Locations between these two extremes would see activity between these listed figures. Morning rates are reduced due to moonlight.

The list below offers the information in tabular form of the showers that I feel are within reach of the visual observer to discern. Hourly rates are often less than one, so these sources are rarely listed as visual targets in most meteor shower lists. If you are like me and wish to associate as many meteors as possible with known sources, then you will appreciate these listings. Before listing meteors from these obscure sources, you should attempt to prove these meteors belong to them and are not chance alignments of sporadic meteors. You can note parameters such as duration, length, radiant distance and the elevation of each meteor to help compute the probability of shower association.  It should be remembered that slow meteors can be seen from fast showers, but fast meteors cannot be produced from slow showers. Slower showers are those with velocities less than 35/km per second. Slow meteors can appear from fast showers when they appear close to the radiant or low in the sky. The table located on page 22 of the IMO’s 2024 Meteor Shower Calendar is a big help in aiding in the identification of meteors. If you record the length and duration of each meteor, you can use this chart to check the probability of the meteor belonging to a shower of known velocity. If the angular velocity is similar to the figure in the table, then your meteor probably belongs to that shower. Rates and positions are exact for Saturday night/Sunday morning.

You can keep track of the activity of these meteor showers as well as those beyond the limits of visual observing by visiting the NASA Meteor Shower Portal. You can move the sky globe to see different areas of the sky. Colored dots indicate shower meteors while white dots indicate sporadic (random) activity. The large orange disk indicates the position of the sun so little activity will be seen in that area of the sky.

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.
  

Tags: Anthelion Meteors Comae Berenicids December Chi Virginids December Meteor Activity December Meteor Showers December rho Virginids December Sigma Virginids Eta Hydrids kappa Velids Meteors Monocerotids Sigma Hydrids theta Pyxidids Ursids

Robert Lunsford

Bob has been interested in the stars as far back as he can recall His first experience with meteors was a biggie, the 1966 Leonid shower. In 1980, a major awaking occurred. He received a sample copy of Meteor News. He was amazed to learn there was a group actually devoted strictly to meteor observing! He joined the group also started to view some of the minor showers list among the pages of Meteor News. Lastly, he was contracted by Springer Publishing in 2007 to write a book on observing meteors. The book is now available and hopefully will be a useful guide to all interested in the enjoyable field of meteor observing.