Meteor Activity Outlook for 14-20 October 2023

Joe Nidd captured this bright fireball at 20:40 NZDT on March 18, 2023 (13:40 UT on March 17), from Dunedin, New Zealand. If you follow the Milky Way in the area of clear sky you can see the brilliant stars of Scorpius, Centaurus, Crux, and Carina as seen from mid-southern latitudes. ©Joe Nidd

During this period, the moon reaches its new phase on Saturday October 14th. As the week progresses, the moon will then enter the evening sky as a waxing crescent but will set before the more active morning hours arrive. The estimated total hourly rates for evening observers this week should be near 3 as seen from mid-northern latitudes (45N) and 2 as seen from tropical southern locations (25S) For morning observers, the estimated total hourly rates should be near 20 as seen from mid-northern latitudes (45N) and 12 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. 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 October 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. 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.

.

The Southern Taurids (002 STA) are active from a wide radiant centered near 02:24 (036) +11. This position lies in southern Aries near the location of the faint star known as xi Arietis. These meteors are best seen near 02:00 local standard time (LST) when the radiant lies highest in the southern sky. Rates are expected to be near 3 per hour no matter your location. With an entry velocity of 27 km/sec., the average STA meteor would be of medium-slow velocity.

The delta Aurigids (224 DAU) are a weak shower active from October 10-18, with maximum activity occurring on the 11th. The radiant is currently located at  05:48 (087) +43. This position lies in central Auriga, 2 degrees southwest of the 2nd magnitude star known as Menkalinan (beta Aurigae). This area of the sky is best placed for observing during the last dark hour prior to dawn, when it lies highest nearly overhead as seen from the mid-northern latitudes.  Current rates are expected to be less than 1 per hour, no matter your location. With an entry velocity of 64 km/sec., the average ORI meteor would be of swift velocity.

The Orionids (008 ORI) are active from October 2 through November 7, with maximum activity occurring on October 22nd. The radiant is currently located at 06:03 (091) +15, which places it in northeastern Orion, just west of the faint star known as nu Orionis. This position is also 7 degrees northeast of the 1st magnitude star known as Betelgeuse (alpha Orionis). This area of the sky is best placed for observing during the last dark hour prior to dawn, when it lies highest in the southern sky.  Current rates are expected to be near 3 per hour, no matter your location. With an entry velocity of 66 km/sec., the average ORI meteor would be of swift velocity.

The epsilon Geminids (023 EGE) are active from October 14-27  with maximum activity occurring on October 18^th. The radiant is currently located at 06:36 (099) +27. This area of the sky lies in southeastern Auriga, 4 degrees southeast of the 4th magnitude star known as kappa Aurigae. To best see these meteors face toward the  east during the last dark hour prior to dawn. Rates at this time should be near 1 per hour as seen from the northern hemisphere and less than one as seen from south of the equator. With an entry velocity of 69 km/sec., the average EGE meteor would be of swift velocity.

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 10 sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates should be near 2 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 1 per hour during the evening hours. Locations between these two extremes would see activity between these listed figures. Evening rates are slightly reduced due to moonlight.

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.