This post discusses the expected meteor activity and lunar conditions for the upcoming week. It is focused on North American latitudes but may be used in all locations. Sky charts displaying current radiant positions are provided for early evening hours, mid-night, and the hour prior to dawn. European readers may wish to use the charts in the same article at www.imo.net for better accuracy.
The Quadrantids can be one of the strongest displays of the year, yet they are difficult to observe. The main factor is that the display of strong activity only has a duration of about 6 hours. The reason the peak is so short is due to the shower’s thin stream of particles and the fact that the Earth crosses the stream at a perpendicular angle. Unlike most meteor showers which originate from comets, the Quadrantids have been found to originate from an asteroid. Asteroid 2003 EH1 takes 5.52 years to orbit the sun. It is possible that 2003 EH1 is a “dead comet” or a new kind of object being discussed by astronomers sometimes called a “rock comet.”
These meteors were first noted in 1825 and appeared to radiate from the obsolete constellation of Quadrans Muralis (Mural Quadrant). Today, this area of the sky lies within the boundaries of the constellation of Boötes the herdsman. During early January nights as seen from the northern hemisphere, this area of the sky lies very low in the northwest in the evening sky. Very little activity is normally seen at this time. As the night progresses this area of the sky swings some 40 degrees beneath the northern celestial pole. From areas south of 40 degrees north latitude, it actually passes below the horizon. It then begins a slow rise into the northeastern sky where it obtains a useful altitude around 02:00 local standard time (depending on your latitude). It is between this time and dawn that you will have your best chance to view these meteors. If the peak occurs during this time you will be in for a treat as rates could exceed 100 per hour as seen from rural locations under a moonless sky. Unlike the 2022 shower, when moonlight was not a problem, the 2023 Quadrantids peak only three days prior to a full moon. This means that the moon will set shortly before dawn, allowing just a small window of opportunity to view this display under dark skies.
Predictions for the peak of the 2023 Quadrantids range from 3:40 to 6:40 Universal Time on January 4th. The earlier time favors European observers while the later peak favors the eastern portion of North America. Note that high latitude sites in Europe such as Scandinavia can observe during this entire period due to their later sunrise. Those viewing from the Southern Hemisphere will not see much activity at all as the radiant does not rise very high in their sky before dawn intervenes.
The best strategy to see the most activity is to face the northeast quadrant of the sky and center your view about half-way up in the sky. By facing this direction you be able to see meteors shoot out of the radiant in all directions. This will make it easy to differentiate between the Quadrantids and random meteors from other sources. To provide a scientific useful observing session one needs to carefully note the starting and ending time of your session. If you are able to provide the time of each meteor, that would help tremendously in analyzing the strength of the shower. The type of meteor needs to be recorded as well as its magnitude. Other parameters that can be recorded are colors, velocity (degrees per second or verbal description) and whether the meteor left a persistent train. Fireballs should be noted and a separate online form filled out after the session.
Serious observers should watch for at least an hour as numerous peaks and valleys of activity will occur. If you only few for a short time it may coincide with a lull of activity. Watching for at least an hour guarantees you will get to see the best this display has to offer. Observers are also encouraged to fill out a visual observing form on the website of the International Meteor Organization located. You must register with the IMO to use the form, but there is an option of registering for free if you do not wish to become a full-fledged member. Data is often scarce for this display, especially when the moon interferes. Therefore if your skies are clear please make an effort to view this display. If will be your last opportunity to view enhanced meteor activity until the Lyrids peak in April.
The Quadrantids also offer those interested in observing meteor showers by radio a good opportunity to view strong activity. Meteors do not emit radio waves, but they act as mirrors and reflect radio waves from distant transmitters which aren’t heard otherwise. This is called forward scatter, opposed to backscatter where the transmitter and receiver are at the same place (radar). For practical reasons the frequency range 50 – 150 MHz (wavelength 6 m – 2 m) is used. This includes amongst others the FM band and TV transmitters which haven’t switched yet to digital. Most reflections are short (less than a second), but brighter meteors can cause reflections lasting minutes. The shortest radio reflections are caused by faint meteors, fainter than visual ones. Contrary to visual rates, the radio rates are not maximal when the radiant of a stream is in the zenith, but rather when it is 45 degrees high. For higher elevations, the rates decrease again. Radio reflections can be observed regardless of daylight or clouds, allowing more complete views of streams. The forward scatter technique will pick up Quadrantids from the afternoon (UT) Jan 3, 2023 until about noon Jan 4, with a maximum around 2-3 h UT. The Quadrantids activity is one of the best of the year, but lasts only a day.
We look forward to seeing your results!
Robert Lunsford & Christian Steyaert
This illustration above depicts the Quadrantid radiant as seen during the morning hours looking low toward the northeast. The brilliant star Arcturus is a good guide to this area of the sky. All Quadrantid meteors will trace back to the radiant area located in northern Bootes. There are several other minor showers active during this time plus random meteors that will appear in different paths than the Quadrantids with different velocities.
December 23, 2022
This post discusses the expected meteor activity and lunar conditions for the upcoming week. It is focused on North American latitudes but may be used in all locations. Sky charts displaying current radiant positions are provided for early evening hours, mid-night, and the hour prior to dawn. European readers may wish to use the charts in the same article at www.imo.net for better accuracy.
Meteor Activity Outlooks for observers in the southern hemisphere are available upon request at: lunro.imo.usa@cox.net
Clear Skies!
Robert Lunsford
ALPO Meteors Section Coordinator
Location of the Ursid (URS) radiant on December 21/22, looking slightly east (right) of due north.
The Ursid meteor shower is the least observed of the major annual showers. In the northern hemisphere December nights are cold and often cloudy. Another hindrance is the fact that it peaks just before the Christmas holiday when many people are busy with holiday festivities. This shower is completely invisible from the southern hemisphere as the radiant lies too far north to be seen from south of the equator this time of year.
The Ursids are active from December 13-24 with a sharp maximum on December 22nd. Activity is normally low away from maximum with rates less than 1 shower member per hour. At maximum activity this source normally adds 5-10 medium velocity meteors to the 15 or so that are normally seen each morning hour from dark sky sites. This year though, the earth passes close to several past trails of debris that closely follow the orbit of comet 8P/Tuttle. This could enhance the Ursid activity seen this year. See the list of encounters in chronological order below listing the year of the debris trail, the expected time of maximum activity and the expected activity:
filament encounter, December 22, 10h 21m UT Expected activity: ZHR=28
843 debris trail, December 22, 14h22m UT Expected activity: ?*
These predictions are no guarantee of enhanced activity as the timing is easier to predict than the density of the dust trails. The moon will be near its new phase and will not be visible at night on December 22nd. Both of these times favor North America, although the 843 event is only visible from Alaska and the western provinces of Canada. The northern polar and sub-polar regions of the Earth are also favored as the radiant remains high in the sky at all times.
At maximum, the Ursid radiant lies just west of the fairly bright (2nd magnitude) orange star known as Kochab (beta Ursae Minoris). To those not familiar with star names, this area lies adjacent to the bowl of the “Little Dipper” as shown in the illustration. This area of the sky lies lowest in the northern sky near 20:00 (8pm) local standard time. This is the worst time to view the Ursids as most of the activity will occur beyond your line of sight, below the northern horizon. As the night progresses the Ursid radiant will slowly rise higher into the northern sky and is best placed during the last dark hour before dawn. To best view this activity it is suggested that you face toward the northern half of the sky. It doesn’t have to be directly at the radiant, but it’s a good idea to have the radiant within your field of view to help with shower association. Don’t look straight up as this is the worst place to look for meteors. Lower you view so that none of the horizon blocks your view. About half way up in the sky is suggested for most observers.
Despite the bitter cold, try to view for at least an hour. Meteor activity is notoriously variable and if you view for only a short time, it may occur during a lull in activity. Viewing for at least an hour ensures you will see several peaks and valleys of activity. An estimate of your limiting magnitude is important in your report as it provides the sky condition during your watch. This is easily done by counting the number of stars visible with certain areas of the sky. Charts for these areas are available at: https://www.imo.net/observations/methods/visual-observation/major/observation/#table1. Areas 1, 7, and 19 on chart #3 would be the easiest to use. Using more than one area is also encouraged to provide more estimates. The conversion table is available in Table 2 on the link provided above. At least two estimates of the limiting magnitude are requested, hopefully at the beginning and end of your session. If conditions change during your session, more estimates will provide a more accurate figure for your data. Helpful tips for visual observing are also available at: https://www.imo.net/observations/methods/visual-observation/ and https://www.imo.net/observations/methods/visual-observation/major/observation/. In order to submit your observations we suggest that you fill out an online visual form provided by the International Meteor Organization. You must register to provide your data, but there is a free option for those not wishing to subscribe to the IMO Journal. Note that not every meteor will be an Ursid. There are several minor showers also active during this period adding a few meteors to the hourly total. There are also upwards of 10 random meteors appearing each hour to add to your count. Therefore shower association of each meteor must be included.
If you have never viewed this shower, be sure to check it out this year as a waxing gibbous moon will interfere with viewing this shower in 2023!
December 16, 2022
This post discusses the expected meteor activity and lunar conditions for the upcoming week. It is focused on North American latitudes but may be used in all locations. Sky charts displaying current radiant positions are provided for early evening hours, mid-night, and the hour prior to dawn. European readers may wish to use the charts in the same article at www.imo.net for better accuracy.
Meteor Activity Outlooks for observers in the southern hemisphere are available upon request at: lunro.imo.usa@cox.net
Clear Skies!
Robert Lunsford
ALPO Meteors Section Coordinator
December 9, 2022
This post discusses the expected meteor activity and lunar conditions for the upcoming week. It is focused on North American latitudes but may be used in all locations. Sky charts displaying current radiant positions are provided for early evening hours, mid-night, and the hour prior to dawn. European readers may wish to use the charts in the same article at www.imo.net for better accuracy.
Meteor Activity Outlooks for observers in the southern hemisphere are available upon request at: lunro.imo.usa@cox.net
Clear Skies!
Robert Lunsford
ALPO Meteors Section Coordinator
December 3, 2022
This post discusses the expected meteor activity and lunar conditions for the upcoming week. It is focused on North American latitudes but may be used in all locations. Sky charts displaying current radiant positions are provided for early evening hours, mid-night, and the hour prior to dawn. European readers may wish to use the charts in the same article at www.imo.net for better accuracy.
