Ursids
Encyclopedia
The Ursids meteor activity begins annually around December 17th and runs for a week plus, until the 25th or 26th. This meteor shower
is named for its radiant
point which is located near the star Beta Ursae Minoris
(Kochab) in the constellation Ursa Minor
.
, which also has some controversy.
The Ursids have a particularly narrow stream, prompting veteran meteor observer, Norman W. McLeod, III (Florida) to comment that the Ursids "must be a compact stream like the Quadrantids
. You have to be within 12 hours of maximum to see much."
Meteor shower
A meteor shower is a celestial event in which a number of meteors are observed to radiate from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at extremely high speeds on parallel trajectories. Most meteors are smaller...
is named for its radiant
Radiant (meteor shower)
The radiant or apparent radiant of a meteor shower is the point in the sky, from which meteors appear to originate. The Perseids, for example, are meteors which appear to come from a point within the constellation of Perseus....
point which is located near the star Beta Ursae Minoris
Beta Ursae Minoris
Beta Ursae Minoris is the second brightest star in the bowl of the "Little Dipper,"the constellation Ursa Minor. It has the traditional name Kochab. Kochab's magnitude is 2.07. It is 16 degrees from Polaris. The star is an orange giant and is 126.4 ± 2.5 light years from Earth. It is 130 times...
(Kochab) in the constellation Ursa Minor
Ursa Minor
Ursa Minor , also known as the Little Bear, is a constellation in the northern sky. Like the Great Bear, the tail of the Little Bear may also be seen as the handle of a ladle, whence the name Little Dipper...
.
History
The Ursids were probably discovered by William F. Denning who observed them for several years around the turn of the 20th century. While there were sporadic observations after, the first coordinated studies of shower didn't begin until Dr. A. Bečvář in 1945. Further observations in the 1970s and ongoing to current have established a relationship with the Tuttle comet8P/Tuttle
8P/Tuttle is a periodic comet in our solar system. Perihelion was late January 2008, and as of February was visible telescopically to Southern Hemisphere observers in the constellation Eridanus. On December 30, 2007 it was in close conjunction with spiral galaxy M33...
, which also has some controversy.
Technical information
Earlier observations described an average radiant of RA=217 deg, DEC=+76 deg, with maximum occurring at a solar longitude of 270.66 deg (about December 22), with the duration being established as December 17-24.The Ursids have a particularly narrow stream, prompting veteran meteor observer, Norman W. McLeod, III (Florida) to comment that the Ursids "must be a compact stream like the Quadrantids
Quadrantids
The Quadrantids are an easily visible January meteor shower.The radiant of this shower is an area inside the constellation Boötes. The name comes from Quadrans Muralis, an obsolete constellation that is now part of Boötes...
. You have to be within 12 hours of maximum to see much."