* Astronomy

Blobrana · L

RE: Quadrantids

Blobrana · L

Astronomers have confirmed the origin of the Quadrantid meteors as a "deep-space explosion" of a comet in 1490 which was observed in China, Japan and Korea, New Scientist reports.
Fourteen astronomers last week tracked the shower's annual display during a nine-hour flight from California to the North Pole. Peter Jenniskens of NASA had previously followed up suspicions that it was caused by the debris of the 1490 event, in which observers spotted a comet "following a path similar to that of the Quadrantids", and which suddenly "flared up".

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Blobrana · L

Last week's Quadrantid meteor shower was probably debris from a deep-space explosion that went off in the late 15th century, new observations reveal.

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Blobrana · L

Quadrantids Meteor Shower

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Blobrana · L

Utahns who were denied seeing the Geminid meteor shower because of cloudiness in December have another chance to see meteors Thursday night.
The Quadrantids are "one of the three best showers of the year," according to Patrick Wiggins, NASA solar system ambassador to Utah.
Peak hours will be Thursday night and into early Friday morning, with more than 100 meteors per hour possible if viewers are away from the city lights.

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Blobrana · L

Anyone who missed out on the fireworks last night will be able to watch the natural version in the form of a meteor shower that starts today

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Blobrana · L

NASA scientists and astronomers will take to the skies in the afternoon of Jan. 3 to observe nature's New Year's celebration: the Quadrantid meteor shower.
Scientists believe this could be the most brilliant meteor shower in 2008 with over 100 visible meteors per hour at its peak. Best viewing times with the highest meteor rates are expected to be in either the late evening of Jan. 3 over Europe and western Asia or the early morning of Jan. 4 over the eastern United States.

We will fly to the North Pole and back to compensate for Earth's rotation and to keep the stream in view throughout the flight - Peter Jenniskens, a principal investigator at NASA's Ames Research Centre, Moffett Field, California, who also works for the SETI Institute, Mountain View, California.

A Gulfstream V aircraft will take off from San Jose, California, to fly scientists and their instruments for 10 continuous hours over the Arctic and back to San Jose. The primary goal of the lengthy airborne mission is to observe the Quadrantid meteor shower in ideal and virtually unchanging conditions far above light pollution and clouds to determine when it peaks and how the stream is dispersed.

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Blobrana · L

The source the Quadrantid meteor shower was unknown until recently. In Dec. 2003 Peter Jenniskens of the NASA Ames Research Centre found evidence that Quadrantid meteoroids come from 2003 EH1, an asteroid that is likely a remnant of a comet, C1490 Y1, that broke apart some 500 years ago, perhaps with a close encounter with Jupiter in 1650, that ejected the into a different orbit. However, ancient Chinese, Korean and Japanese astronomers had described brightening in what must have been a violent explosion that occurred between Dec. 31, 1490, and Feb. 12, 1491.
The Earth intersects the orbit of 2003 EH1 at a perpendicular angle, which means that we quickly move through any debris--hence the rapid decline in the meteor rates.
Assuming an average albedo, asteroid 2003 EH1 is estimated to be only about 2.1 ± 0.8 km in diameter.

Meteor Orbit	Photographic	Radio-echo
Argument of Perihelion () [J2000]	170.7 deg.	168.1 deg.
Ascending Node () [J2000]	283.3 deg.	283.0 deg.
Inclination (i) [J2000]	71.4 deg.	70.3 deg.
Perihelion Distance (q)	0.975 AU	0.974 AU
Eccentricity (e)	0.614	0.682
Semimajor axis (a)	2.526 AU	3.064 AU

The brightest pulse

This annual meteor shower is active from January 1 through January 5, peaking around 18h20m UT on January 4th. The Quadrantids are named after an old and unused constellation, Quadrans Muralis, and the radiant lies now in top region of Boötes the Herdsman, average Position(j2000): RA=229 deg, DEC=+49 deg.
An Italian astronomer recorded the first observations of the Quadrantid meteors on Jan. 2, 1825. Though, the age of the shower is estimated at 5,400 years .

The shower

is of course seen best before dawn when the radiant is at its highest position ( For the Northern Hemisphere).
The Quadrantids are not considered a good meteor display for observers in the Southern Hemisphere. The radiant rises above the horizon for a short time during morning daylight. The rates of meteors are highly variable, doubling from 60 per hour to 120 per hour for brief periods. But normally, 100 meteors per hour, if the radiant lies directly overhead.
The meteors are medium velocity (41 km/h), that have a bluish tinge to them.
The Last Quarter Moon in Virgo, rises in the east around midnight, so may drown out the fainter trails. Boötes rises in the northeast at 2 AM on January 4. The Earth will also be at perihelion, the point in its orbit closest to the Sun.

Blobrana · L

RE: Quadrantid Radiant

Blobrana · L

RE: Quadrantids