Ursids

Last updated
Ursids (URS)
Radiant for Ursids 2018.jpg
Ursa Minor with the radiant of the Ursids marked in red
Parent body 8P/Tuttle [1]
Radiant
Constellation Ursa Minor (near Kochab)
Right ascension 14h 36m [2]
Declination +75.3° [2] (Northern Hemisphere)
Properties
Occurs duringDecember 17 – December 26 [1]
Date of peakDecember 22 [1]
Velocity33 [2]  km/s
Zenithal hourly rate 10 [1]
See also: List of meteor showers

The Ursid (URS) meteor activity begins annually around December 17 and runs for over a week, 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.

Contents

History

The Ursids were probably discovered by William F. Denning, who observed them for several years around the start of the 20th century. [1] While there were sporadic observations after, the first coordinated studies of the shower didn't begin until Dr. A. Bečvář observed an outburst of 169 per hour in 1945. [1] Further observations in the 1970s and ongoing to current have established a relationship with comet 8P/Tuttle. [1] Peter Jenniskens and Esko Lyytinen discovered that outbursts could happen when comet Tuttle was at aphelion because some meteoroids get trapped in the 7/6 orbital resonance with Jupiter.

Technical information

Earlier observations described an average radiant of RA=217°, DEC=76°, [1] 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. You have to be within 12 hours of maximum to see much." [1]

Related Research Articles

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<span class="mw-page-title-main">Geminids</span>

The Geminids are a prolific meteor shower caused by the object 3200 Phaethon, which is thought to be a Palladian asteroid with a "rock comet" orbit. This would make the Geminids, together with the Quadrantids, the only major meteor showers not originating from a comet. The meteors from this shower are slow moving, can be seen in December and usually peak around December 4–16, with the date of highest intensity being the morning of December 14. The shower is thought to be intensifying every year and recent showers have seen 120–160 meteors per hour under optimal conditions, generally around 02:00 to 03:00 local time. Geminids were first observed in 1862, much more recently than other showers such as the Perseids and Leonids.

<span class="mw-page-title-main">Meteor shower</span> Celestial event caused by streams of meteoroids entering Earths atmosphere

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<span class="mw-page-title-main">46P/Wirtanen</span> Periodic comet with 5 year orbit

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<span class="mw-page-title-main">55P/Tempel–Tuttle</span> Periodic comet with an orbital period of 33 years, parent body of the Leonid meteor shower

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<span class="mw-page-title-main">15P/Finlay</span> Periodic comet with 6 year orbit

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The October Draconids, in the past also unofficially known as the Giacobinids, are a meteor shower whose parent body is the periodic comet 21P/Giacobini-Zinner. They are named after the constellation Draco, where they seemingly come from. Almost all meteors which fall towards Earth ablate long before reaching its surface. The Draconids are best viewed after sunset in an area with a clear dark sky.

<span class="mw-page-title-main">Lyrids</span> Meteor shower occur in April

The April Lyrids are a meteor shower lasting from April 16 to April 25 each year. The radiant of the meteor shower is located in the constellation Lyra, near its brightest star, Vega. The peak of the shower is typically around April 22 each year.

<span class="mw-page-title-main">Arietids</span>

The Arietids are a strong meteor shower that lasts from May 22 to July 2 each year, and peaks on June 7. The Arietids, along with the Zeta Perseids, are the most intense daylight meteor showers of the year. The source of the shower is unknown, but scientists suspect that they come from the asteroid 1566 Icarus, although the orbit also corresponds similarly to 96P/Machholz.

<span class="mw-page-title-main">Andromedids</span> Meteor shower is associated with Bielas Comet

The Andromedids meteor shower is associated with Biela's Comet, the showers occurring as Earth passes through old streams left by the comet's tail. The comet was observed to have broken up by 1846; further drift of the pieces by 1852 suggested the moment of breakup was in either 1842 or early 1843, when the comet was near Jupiter. The breakup led to particularly spectacular showers in subsequent cycles.

<span class="mw-page-title-main">Tau Herculids</span> Annual meteor shower in May/June

The Tau Herculids are a meteor shower that when discovered in 1930 appeared to originate from the star Tau Herculis. The parent comet of the Tau Herculids is periodic comet Schwassmann-Wachmann 3 with a 5.4 year orbital period. This meteor shower occurs from May 19 - June 19. The meteor shower was first observed by the Kwasan Observatory in Kyoto, Japan in May 1930. The Tau Herculids' average radiant was α=236°, δ=+41°. Due to orbital perturbations of the meteor streams by Jupiter, 2022 activity will have a radiant of R.A. = 13:56 (209), Decl. = +28. The meteors are relatively slow moving making atmospheric entry at around 16 km/s (36,000 mph).

<span class="mw-page-title-main">209P/LINEAR</span>

209P/LINEAR is a periodic comet discovered on 3 February 2004 by Lincoln Near-Earth Asteroid Research (LINEAR) using a 1.0-metre (39 in) reflector. Initially it was observed without a coma and named 2004 CB as a minor planet or asteroid, but in March 2004 Robert H. McNaught observed a comet tail which confirmed it as a comet. It was given the permanent number 209P on 12 December 2008 as it was the second observed appearance of the comet. Prediscovery images of the comet, dating back to December 2003, were found during 2009. Arecibo imaging in 2014 showed the comet nucleus is peanut shaped and about 2.4 km in diameter. The comet has extremely low activity for its size and is probably in the process of evolving into an extinct comet.

<span class="mw-page-title-main">Cameras for All-Sky Meteor Surveillance</span> Meteor shower observatory

CAMS is a NASA-sponsored international project that tracks and triangulates meteors during night-time video surveillance in order to map and monitor meteor showers. Data processing is housed at the Carl Sagan Center of the SETI Institute in California, USA. Goal of CAMS is to validate the International Astronomical Union's Working List of Meteor Showers, discover new meteor showers, and predict future meteor showers.

References

  1. 1 2 3 4 5 6 7 8 9 Gary W. Kronk. "Observing the Ursids". Meteor Showers Online. Archived from the original on 2013-07-24. Retrieved 2012-11-17.
  2. 1 2 3 IMO Meteor Shower Calendar: Ursids (URS)