View source for Boötes

=== Meteor showers ===
[[File:Quad2011.324.JPG|thumb|left|A Quadrantid captured by an all-sky camera during a 4-second exposure]]
Boötes is home to the [[Quadrantid]] [[meteor shower]], the most prolific annual meteor shower. It was discovered in January 1835 and named in 1864 by Alexander Herschel.{{sfn|Jenniskens|2006|pp=357–368}} The [[radiant (meteor shower)|radiant]] is located in northern Boötes near Kappa Boötis,{{sfn|Jenniskens|2006|p=612}} in its namesake former constellation of Quadrans Muralis. Quadrantid meteors are dim, but have a peak visible hourly rate of approximately 100 per hour on January 3–4.{{sfn|Ridpath|2001|pp=88–89}}{{sfn|Moore|Tirion|1997|pp=132–133}} The [[zenithal hourly rate]] of the Quadrantids is approximately 130 meteors per hour at their peak; it is also a very narrow shower.

The Quadrantids are notoriously difficult to observe because of a low radiant and often inclement weather. The parent body of the meteor shower has been disputed for decades;{{sfn|Jenniskens|2006|pp=357–368}} however, [[Peter Jenniskens]] has proposed [[(196256) 2003 EH1|2003 EH<sub>1</sub>]], a minor planet, as the parent.{{sfn|Jenniskens|2006|p=368}} 2003 EH<sub>1</sub> may be linked to [[Qingyang event|C/1490 Y<sub>1</sub>]], a comet previously thought to be a potential parent body for the Quadrantids.{{sfn|Jenniskens|2006|p=373}}{{sfn|Jenniskens|2006|p=376}}

2003 EH<sub>1</sub> is a [[short-period comet]] of the [[Jupiter family comet|Jupiter family]]; 500 years ago, it experienced a catastrophic breakup event. It is now dormant.{{sfn|Jenniskens|2012}} The Quadrantids had notable displays in 1982, 1985 and 2004.{{sfn|Levy|2008|p=49}} Meteors from this shower often appear to have a blue hue and travel at a moderate speed of 41.5–43 kilometers per second.{{sfn|Levy|2008|p=104}}

On April 28, 1984, a remarkable outburst of the normally placid [[Alpha Bootids]] was observed by visual observer Frank Witte from 00:00 to 2:30 UTC. In a 6&nbsp;cm telescope, he observed 433 meteors in a field of view near Arcturus with a diameter of less than 1°. [[Peter Jenniskens]] comments that this outburst resembled a "typical dust trail crossing".{{sfn|Jenniskens|2006|p=199}} The Alpha Bootids normally begin on April 14, peaking on April 27 and 28, and finishing on May 12.{{sfn|Levy|2008|p=110}} Its meteors are slow-moving, with a velocity of 20.9 kilometers per second.{{sfn|IAU Alpha Bootids}} They may be related to Comet [[73P/Schwassmann–Wachmann]] 3, but this connection is only theorized.{{sfn|Levy|2008|p=110}}

[[File:QUADRANTID meteor on January 3 2009.jpg|thumb|A bright Quadrantid observed at twilight]]

The [[June Bootids]], also known as the Iota Draconids, is a meteor shower associated with the comet [[7P/Pons–Winnecke]], first recognized on May 27, 1916, by William F. Denning.{{sfn|Jenniskens|2006|p=334}} The shower, with its slow meteors, was not observed prior to 1916 because Earth did not cross the comet's dust trail until Jupiter perturbed Pons–Winnecke's orbit, causing it to come within {{Convert|0.03|AU|e6km e6mi|abbr=unit|lk=in}} of Earth's orbit the first year the June Bootids were observed.

In 1982, E. A. Reznikov discovered that the 1916 outburst was caused by material released from the comet in 1819.{{sfn|Jenniskens|2006|p=335}} Another outburst of the June Bootids was not observed until 1998, because Comet Pons–Winnecke's orbit was not in a favorable position. However, on June 27, 1998, an outburst of meteors radiating from Boötes, later confirmed to be associated with Pons-Winnecke, was observed. They were incredibly long-lived, with trails of the brightest meteors lasting several seconds at times. Many [[Meteoroid#Fireball|fireball]]s, green-hued trails, and even some meteors that cast shadows were observed throughout the outburst, which had a maximum zenithal hourly rate of 200–300 meteors per hour.{{sfn|Jenniskens|2006|p=336–337}}

Two Russian astronomers determined in 2002 that material ejected from the comet in 1825 was responsible for the 1998 outburst.{{sfn|Jenniskens|2006|p=338}} [[Ejecta]] from the comet dating to 1819, 1825 and 1830 was predicted to enter Earth's atmosphere on June 23, 2004. The predictions of a shower less spectacular than the 1998 showing were borne out in a display that had a maximum zenithal hourly rate of 16–20 meteors per hour that night. The June Bootids are not expected to have another outburst in the next 50 years.{{sfn|Jenniskens|2006|p=339–344}}

Typically, only 1–2 dim, very slow meteors are visible per hour; the average June Bootid has a magnitude of 5.0. It is related to the [[Alpha Draconids]] and the [[Bootids-Draconids]]. The shower lasts from June 27 to July 5, with a peak on the night of June 28.{{sfn|Levy|2008|p=113}} The June Bootids are classified as a class III shower (variable),{{sfn|AMS 2012 List}} and has an average entry velocity of 18 kilometers per second. Its radiant is located 7 degrees north of Beta Boötis.{{sfn|AMS June 23}}

The [[Beta Bootids]] is a weak shower that begins on January 5, peaks on January 16, and ends on January 18. Its meteors travel at 43&nbsp;km/s.{{sfn|Levy|2008|p=105}} The [[January Bootids]] is a short, young meteor shower that begins on January 9, peaks from January 16 to January 18, and ends on January 18.{{sfn|Levy|2008|p=106}}

The [[Phi Bootids]] is another weak shower radiating from Boötes. It begins on April 16, peaks on April 30 and May 1, and ends on May 12.{{sfn|Levy|2008|p=110}} Its meteors are slow-moving, with a velocity of 15.1&nbsp;km/s. They were discovered in 2006.{{sfn|IAU Phi Bootids}} The shower's peak hourly rate can be as high as six meteors per hour. Though named for a star in Boötes, the Phi Bootid radiant has moved into Hercules.{{sfn|Koed|Sherrod|2003|p=52}} The meteor stream is associated with three different asteroids: [[1620 Geographos]], [[2062 Aten]] and [[1978 CA]].{{sfn|Štohl|Porubčan|1993|p=43}}

The [[Lambda Bootids]], part of the [[Bootid-Coronae Borealid Complex]], are a weak annual shower with moderately fast meteors; 41.75&nbsp;km/s.{{sfn|IAU Lambda Bootids}} The complex includes the Lambda Bootids, as well as the [[Theta Coronae Borealids]] and [[Xi Coronae Borealids]].{{sfn|IAU Bootid-Coronae Borealid Complex}}{{sfn|Green|2007}} All of the Bootid-Coronae Borealid showers are [[Jupiter family comet]] showers; the streams in the complex have highly inclined orbits.{{sfn|Jenniskens|2012}}

There are several minor showers in Boötes, some of whose existence is yet to be verified. The [[Rho Bootids]] radiate from near the namesake star, and were hypothesized in 2010.{{sfn|IAU Rho Bootids}} The average Rho Bootid has an entry velocity of 43&nbsp;km/s.{{sfn|IAU Rho Bootids}}{{sfn|Brown|Wong|Weryk|Wiegert|2010}} It peaks in November and lasts for three days.

The Rho Bootid shower is part of the [[SMA complex]], a group of meteor showers related to the [[Taurids]], which is in turn linked to the comet [[2P/Encke]]. However, the link to the Taurid shower remains unconfirmed and may be a chance correlation.{{sfn|Brown|Wong|Weryk|Wiegert|2010}} Another such shower is the [[Gamma Bootids]], which were hypothesized in 2006. Gamma Bootids have an entry velocity of 50.3&nbsp;km/s.{{sfn|IAU Gamma Bootids}} The [[Nu Bootids]], hypothesized in 2012, have faster meteors, with an entry velocity of 62.8&nbsp;km/s.{{sfn|IAU Nu Bootids}}