Earth and Space News: February meteor showers

Showing posts with label February meteor showers. Show all posts

Wednesday, February 20, 2019

February Mu Virginids Shower Earth’s Skies February to Early March

Summary: The February mu Virginids shower Earth’s skies February to early March, with peak activity expected around Feb. 25 to Feb. 26.

The February mu Virginid meteor shower appears to radiate from an area near Mu Virginis in southeastern Virgo the Virgin constellation; Hercules (HER) constellation map credit: IAU and Sky & Telescope (Roger Sinnott and Rick Fienberg; constellation patterns by Alan MacRoberts), CC BY 4.0 International, via IAU (International Astronomical Union)

The recently detected February mu Virginids shower Earth’s skies February to early March, the meteor shower’s annual activity dates, with an expected peak around Feb. 25 or Feb. 26.

The announcement of the discovery of the February mu Virginids as one of eight new showers appeared in the June 2013 issue of WGN, the Journal of the International Meteor Organization. The eight new showers emerged from radiant analyses of 133,653 orbits culled from Croatian Meteor Network catalogues for 2007 to 2010 and Japan’s SonotaCo Network catalogues from 2007 to 2011. The Croatian Meteor Network’s report credited the February mu Virginids with 21 known orbits.

The discoverers of the February mu Virginids described the shower as weak “with moderate duration.” They initially assigned activity dates of Feb. 7 to Feb. 27. The February mu Virginids were identified as active between solar longitudes 318 and 338.

Robert Lunsford, the American Meteor Society’s Meteor Activity Outlook weekly columnist, placed annual activity dates from Feb. 16 to March 4 for 2018. He expanded the 2017 and 2016 activity dates by one day, with the shower beginning Feb. 15 and ending March 4.

Lunsford’s predicted peak date for the 2018 February mu Virginids was Feb. 25. Peak activity in 2017 and 2016 was predicted to occur Feb. 26.

Lunsford describes the February mu Virginids as producing “mostly swift meteors.” He places entry into Earth’s atmosphere at a velocity of 62 kilometers per second (38.52 miles per second). The Croatian Meteor Network’s report valued the entry velocity of the February mu Virginid members at 66.9 kilometers per second (41.56 miles per second), with a standard deviation of plus or minus 0.7.

Lunsford predicts rates of less than one February mu Virginid meteor per hour at all viewing locations. He recommends around 5 a.m. local standard time for best viewing, with the shower’s apparent point of origin, known as radiant, appearing high above the horizon.

The February mu Virginids appear to radiate from the vicinity of Mu Virginis (μ Virginis; mu Vir, μ Vir) in southeastern Virgo the Virgin constellation, near Virgo’s border with northwestern Libra the Scales constellation. The fourth magnitude star lies in the Southern Celestial Hemisphere, less than six degrees south of the celestial equator, astronomy’s projection of Earth’s equator onto space’s imaginary sphere.

Virgo the Virgin’s straddling of the celestial equator qualifies the sky’s second largest constellation as an equatorial constellation. Virgo’s visibility stretches from 80 degrees north latitude to 80 degrees south latitude.

The Croatian Meteor Network’s discovery report of the February mu Virginids approximates the shower’s daily motion for right ascension (RA; similar to geographical longitude) at 0.8 degrees per day. Declination (DEC; similar to geographical latitude) has a rough value of minus 0.4 degrees per day. The superposition of the shower’s members with Earth’s movements determines the shower’s radiant drift.

For the 2016 February mu Virginids, Lunsford tracked radiant drift from constellation Virgo to Ophiuchus the Serpent Bearer constellation. The radiant Saturday, Feb. 13, to Sunday, Feb. 14, favored southeastern Virgo, five degrees east of dim, fourth magnitude star Iota Virginis (ι Virginis; Iota Vir, ι Vir). The radiant Saturday, Feb. 27, to Sunday, Feb. 28, associated with southern Ophiuchus, near the fourth magnitude, triple star system of Lambda Ophiuchi (λ Ophiuchi; Lambda Oph, λ Oph).

The parent body of the February mu Virginids is unknown. The Croatian Meteor Network report stated: “Note that geocentric velocity is very well defined for this shower, which may indicate a relatively young shower.”

Damir Šegon of Croatia’s Astronomical Society Istra Pula and Višnjan Science and Education Center and five other members of the Croatian Meteor Network are credited with discovery of the February mu Virginids. Šegon shares the discovery with Željko Andreić of the University of Zagreb; Korado Korlević of Višnjan Science and Education Center; Filip Novoselnik, Denis Vida and Ivica Skokić of Astronomical Society “Anonymus” and University of Osijek.

As chair of the IAU (International Astronomical Union) Commission 22’s Task Group on Meteor Shower Nomenclature, Dutch and American astronomer Peter Jenniskens reported the recognition of the February mu Virginids as a new meteor shower via IAU’s Central Bureau Electronic Telegram no. 3707, Nov. 12, 2013. The IAU designates the new shower as 00516 FMV.

The takeaways for the February mu Virginids, which shower Earth’s skies annually from February to early March, are that peak activity by the shower’s swiftly moving meteors happens around Feb. 24 to Feb. 25, the shower’s parent body is unknown and the shower’s discovery was reported in June 2013.

Mu (μ) Virginis, namesake of February mu Virginid meteor shower, represents the right foot in Virgo the Virgin constellation; Alexander Jamieson, A Celestial Atlas, Plate XVIII: Public Domain, via U.S. Naval Observatory Library

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

The February mu Virginid meteor shower appears to radiate from an area near Mu Virginis in southeastern Virgo the Virgin constellation; Virgo (VIR) constellation map credit: IAU and Sky & Telescope (Roger Sinnott and Rick Fienberg; constellation patterns by Alan MacRoberts), CC BY 4.0 International, via IAU (International Astronomical Union) @ https://www.iau.org/public/themes/constellations/#com

“00516 FMV February mu Virginids.” IAU (International Astronomical Union) Meteor Data Center > List of All Meteor Showers.
Available @ https://www.ta3.sk/IAUC22DB/MDC2007/Roje/pojedynczy_obiekt.php?kodstrumienia=00516&colecimy=0&kodmin=00001&kodmax=01032&sortowanie=0

Dibon-Smith, Richard. “α Virginis.” The Constellations.
Available @ http://www.dibonsmith.com/vir_a.htm

Espenak, Fred. “Phases of the Moon: 2001-2010 Universal Time.” AstroPixels > Ephemeris > Moon > Six Millennium Catalog of Phases of the Moon: Moon Phases From -1999 to +4000 (2000 BCE to 4000 CE).
Available @ http://astropixels.com/ephemeris/phasescat/phases2001.html

Garfinkle, Robert. Star-Hopping: Your Visa to Viewing the Universe. Cambridge, England: Cambridge; New York NY; Melbourne, Australia: University Press, 1994.

Jamieson, Alexander. A Celestial Atlas: Comprising a Systematic Display of the Heavens in a Series of Thirty Maps Illustrated by Scientific Description of Their Contents and Accompanied by Catalogues of the Stars and Astronomical Exercises. London England: G. & W.B. Whittaker, 1822.
Available via U.S. Naval Observatory Library @ http://aa.usno.navy.mil/library/

Jenniskens, P. (Peter). “New Meteor Showers Recognized.” CBET (Central Bureau for Electronic Telegrams), no. 3707. Nov. 12, 2013. Edited by Daniel W.E. Green.
Available via Harvard University’s Central Bureau for Astronomical Telegrams @ http://www.cbat.eps.harvard.edu/cbet/003700to003800.txt

Jenniskens, Peter. Meteor Showers and Their Parent Comets. Cambridge, England: Cambridge University Press, 2006.

Lunsford, Robert. “Meteor Activity Outlook for February 13-19, 2016.” American Meteor Society. Feb. 14, 2016.
Available @ https://www.amsmeteors.org/2016/02/meteor-activity-outlook-for-february-13-19-2016/

Lunsford, Robert. “Meteor Activity Outlook for Feb. 17-23, 2018.” American Meteor Society. Feb. 16, 2018.
Available @ https://www.amsmeteors.org/2018/02/meteor-activity-outlook-for-february-17-23-2018/

Lunsford, Robert. “Meteor Activity Outlook for February 18-24, 2017.” American Meteor Society. Feb. 17, 2017.
Available @ https://www.amsmeteors.org/2017/02/meteor-activity-outlook-for-february-18-24-2017/

Lunsford, Robert. “Meteor Activity Outlook for February 24-March 2, 2018.” American Meteor Society. Feb. 22, 2018.
Available @ https://www.amsmeteors.org/2018/02/meteor-activity-outlook-for-february-24-march-2-2018/

Lunsford, Robert. “Meteor Activity Outlook for February 25-March 3, 2017.” American Meteor Society. Feb. 24, 2017.
Available @ https://www.amsmeteors.org/2017/02/meteor-activity-outlook-for-february-25-march-3-2017/

Lunsford, Robert. “Meteor Activity Outlook for Feb 27-March 4, 2016.” American Meteor Society. Feb. 28, 2016.
Available @ https://www.amsmeteors.org/2016/02/meteor-activity-outlook-for-february-27-march-4-2016/

Lunsford, Robert. Meteors and How to Observe Them. Astronomers’ Observing Guides. New York NY: Springer Science+Business Media, 2009.

Marriner, Derdriu. "2019 February Epsilon Virginids Shower Earth’s Skies Jan. 29 to Feb. 9." Earth and Space News. Wednesday, Jan. 30, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/01/2019-february-epsilon-virginids-shower.html

“Moon Phases February 2019.” Calendar-12.com > Moon Calendar > 2019.
Available @ https://www.calendar-12.com/moon_calendar/2019/february

“Moon Phases March 2019.” Calendar-12.com > Moon Calendar > 2019.
Available @ https://www.calendar-12.com/moon_calendar/2019/march

Ofek, Eran. “Convert Solar Longitude to JD & Date.” Tel Aviv University School of Physics & Astronomy Department of Astrophysics > Wise Observatory.
Available @ http://wise-obs.tau.ac.il/~eran/Wise/Util/SolLon.html

Šegon, Damir; Željko Andreić; Korado Korlević; Filip Novoselnik; Denis Vida; Ivica Skokić. “8 New Showers From Croatian Meteor Network Data.” WGN, vol. 41, no. 3 (June 2013): 70-74.
Available via via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://articles.adsabs.harvard.edu/full/2013JIMO...41...70S
Available via IMO @ https://www.imo.net/publications/wgn/

Tatum, Jeremy B. “Where Is the Radiant?” Journal of the Royal Astronomical Society of Canada, vol. 101 (February/février 2007), no. 1: 14-24.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://adsabs.harvard.edu/full/2007JRASC.101...14T

Wednesday, February 13, 2019

Annual Beta Herculids Briefly Shower Earth’s Skies Feb. 11 to Feb. 15

Summary: The beta Herculids briefly shower Earth’s skies Feb. 11 to Feb. 15, the shower’s annual activity dates, with peak activity around Feb. 12 to Feb. 14.

February’s beta Herculid meteor shower appears to radiate from an area near Kornephoros (Beta Herculis) in southwestern Hercules the Hero constellation; Hercules (HER) constellation map credit: IAU and Sky & Telescope (Roger Sinnott and Rick Fienberg; constellation patterns by Alan MacRoberts), CC BY 4.0 International, via IAU (International Astronomical Union)

The beta Herculids shower Earth’s skies Feb. 11 to Feb. 15, the meteor shower’s annual activity dates, with an expected peak around Feb. 12, Feb. 13 or Feb. 14.

Robert Lunsford, the American Meteor Society’s Meteor Activity Outlook weekly columnist, predicted peak activity Feb. 14 for the 2015 to 2018 beta Herculid showers and Feb. 13 for the 2014 shower. Carl Hergenrother, staff scientist with University of Arizona’s Lunar and Planetary Laboratory, assigned peak activity to Feb. 13 for the 2011 and 2013 beta Herculid showers and Feb. 12 for the 2010 shower. The IMO (International Meteor Organization) Video Meteor Network’s report for February 2010 noted the occurrence of the shower’s expected profile maximum on Feb. 12.

Increasingly luminous moon phases coincide with the 2019 beta Herculids. The first quarter phase Tuesday, Feb. 12, shines with 46 percent surface visibility and transitions to the waxing gibbous phase with 67 percent visibility, on Thursday, Feb. 14, and 77 percent visibility Friday, Feb. 15.

The beta Herculids’ name reflects the shower’s radiant, or apparent point of origin, in southwestern Hercules the Hero constellation. Beta Herculid activity appears to radiate from Beta Herculis (β Herculis; Beta Her, β Her), the constellation’s brightest star. Lunsford placed the radiant for the 2018 peak date, Feb. 14, at 3 degrees north of the third magnitude binary star.

Beta Herculis has the traditional name of Kornephoros (“club bearer”), a Greek epithet for the divine hero of Greek and Roman myths. Beta Herculis marks the Hero’s right shoulder in the traditional view of constellation Hercules.

In addition to its radiant status, Beta Herculis star hops binocular and telescopic observers to NGC 6210. The planetary nebula, discovered in 1825 by German-Russian astronomer Friedrich Georg Wilhelm von Struve (April 15, 1793-Nov. 23, 1864), lies 4 degrees northeast of Beta Herculis.

Hercules the Hero constellation lies in the Northern Celestial Hemisphere, the northern half of the imaginary sphere projected by astronomy into space. The constellation’s farthest southern boundary stretches to about 3 degrees north of the celestial equator.

Lunsford describes the beta Herculid shower as producing “mostly swift meteors.” Beta Herculid meteors enter Earth’s atmosphere at velocities of 53 to 56 kilometers per second (32.9 to 34.79 miles per second), according to Lunsford and Hergenrother, respectively.

The beta Herculids are considered a weak shower. The shower has an expected rate of less than one per hour, even during peak activity, according to Hergenrother and Lunsford.

The IMO Video Meteor Network’s report for February 2013 described the month as “poor in meteor showers -- perhaps the month with fewest meteor showers of all.” Nevertheless, the network’s data revealed approximately 150 beta Herculid meteors. The report noted: “Between February 13 and 16, the shower is continuously among the five strongest meteor sources in the sky and reaches a rank of four, at maximum.”

The beta Herculids were detected through the IMO Video Meteor Network’s continuous monitoring database. In addition to the main data set 1999 through June 2009, meteors that were recorded from 1993 to 1998, prior to the IMO network’s start, were analyzed. The IMO Video Meteor Network dates to March 1999 with a first station in Germany’s westernmost city, Aachen, in North Rhine-Wesphalia state.

Amateur astronomer and BMW information technologist Sirko Molau and Jürgen Rendtel of northeastern Germany’s Leibniz Institute for Astrophysics Potsdam (AIP) discovered the beta Herculids during a check of the data for short duration showers. The authors’ check revealed nine additional sources, including the new shower.

As chair of the IAU (International Astronomical Union) Commission 22’s Task Group on Meteor Shower Nomenclature, Dutch and American astronomer Peter Jenniskens reported the recognition of the beta Herculids as a new meteor shower via IAU’s Central Bureau Electronic Telegram July 4, 2011. The IAU designates the new shower as 00418 BHE.

Molau and Rendtel identified between 322 and 326 degrees as the solar longitudes of individual orbits associated with the meteor stream. A conversion to Earth dates (Julian calendar) yields Feb. 10 to Feb. 15. The discoverers noted the activity dates as “a period with a generally low meteor activity and thus suited for the detection of weak sources.”

The parent body for the beta Herculids is unknown.

The takeaways for the February beta Herculids, which shower Earth’s skies annually from Feb. 11 to Feb. 15, are that peak activity by the shower’s swiftly moving meteors happens around Feb. 12 to Feb. 14, the shower’s parent body is unknown and the shower’s radiant, Kornephoros (Beta Herculis) star hops binocular and telescopic gazers to a Milky Way planetary nebula, NGC 6210.

Beta Herculis, namesake of the beta Herculid meteor shower, star hops binocular and telescopic stargazers to NGC 6210, a Milky Way planetary nebula; image by Hubble Space Telescope’s Wide Field Planetary Camera 2 (WFPC2): ESA/Hubble and NASA, CC BY 4.0 International, via Hubble Space Telescope

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

“00418 BHE beta Herculids.” IAU (International Astronomical Union) Meteor Data Center > List of All Meteor Showers.
Available @ https://www.ta3.sk/IAUC22DB/MDC2007/Roje/pojedynczy_obiekt.php?kodstrumienia=00418&colecimy=0&kodmin=00001&kodmax=01032&sortowanie=0

Arlt, Rainer, comp. “Solar Longitudes for 2009.” WGN, vol. 36, no. 6 (December 2008): 118-119.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://articles.adsabs.harvard.edu/full/2008JIMO...36..118A
Available via IMO @ https://www.imo.net/publications/wgn/

Garfinkle, Robert. Star-Hopping: Your Visa to Viewing the Universe. Cambridge, England: Cambridge; New York NY; Melbourne, Australia: University Press, 1994.

Hergenrother, Carl. “Feb 10/11 to 13/14 Meteors.” The Transient Sky -- Comets, Asteroids, Meteors > Archives > February 2011. Feb. 15, 2011.
Available @ https://transientsky.com/2011/02/15/feb-1011-to-1314-meteors/

Hergenrother, Carl. “Jan 28/29 to Feb 12/13 Meteors.” The Transient Sky -- Comets, Asteroids, Meteors > Archives > February 2010. Feb. 13, 2010.
Available @ https://transientsky.com/2010/02/13/jan-2829-to-feb-1213-meteors/

Hergenrother, Carl. “Meteor Activity Outlook for February 9-15, 2013.” The Transient Sky -- Comets, Asteroids, Meteors > Archives > February 2013. Feb. 9, 2013.
Available @ https://transientsky.com/2013/02/09/meteor-activity-outlook-for-february-9-15-2013/

Hergenrother, Carl. “Meteor Activity Outlook for February 12-18, 2011.” The Transient Sky -- Comets, Asteroids, Meteors > Archives > February 2011. Feb. 15, 2011.
Available @ https://transientsky.com/2011/02/15/meteor-activity-outlook-for-february-12-18-2011/

Hergenrother, Carl. “Meteor Activity Outlook for February 13-19, 2010.” The Transient Sky -- Comets, Asteroids, Meteors > Archives > February 2011. Feb. 13, 2010.
Available @ https://transientsky.com/2010/02/13/meteor-activity-outlook-for-february-13-19-2010/

Hergenrother, Carl. “Meteor Activity Outlook for February 16-22, 2013.” The Transient Sky -- Comets, Asteroids, Meteors > Archives > February 2013. Feb. 17, 2013.
Available @ https://transientsky.com/2013/02/17/meteor-activity-outlook-for-february-16-22-2013-2/

Jenniskens, P. (Peter). “New Meteor Showers Recognized.” CBET (Central Bureau for Electronic Telegrams), no. 2758. July 4, 2011. Edited by Daniel W.E. Green.
Available via Harvard University’s Central Bureau for Astronomical Telegrams @ http://www.cbat.eps.harvard.edu/cbet/002700/CBET002758.txt

Jenniskens, Peter. Meteor Showers and Their Parent Comets. Cambridge, England: Cambridge University Press, 2006.

Lunsford, Robert. “Meteor Activity Outlook for Feb. 10-16, 2018.” American Meteor Society. Feb. 9, 2018.
Available @ https://www.amsmeteors.org/2018/02/meteor-activity-outlook-for-february-10-16-2018/

Lunsford, Robert. “Meteor Activity Outlook for February 11-17, 2017.” American Meteor Society. Feb. 9, 2017.
Available @ https://www.amsmeteors.org/2017/02/meteor-activity-outlook-for-february-11-17-2017/

Lunsford, Robert. “Meteor Activity Outlook for February 14-20, 2015.” American Meteor Society. Feb. 11, 2015.
Available @ https://www.amsmeteors.org/2015/02/meteor-activity-outlook-for-february-14-20-2015/

Lunsford, Robert. “Meteor Activity Outlook for February 15-21, 2014.” American Meteor Society. Feb. 14, 2014.
Available @ https://www.amsmeteors.org/2014/02/meteor-activity-outlook-for-february-15-21-2014/

Lunsford, Robert. Meteors and How to Observe Them. Astronomers’ Observing Guides. New York NY: Springer Science+Business Media, 2009.

Marriner, Derdriu. "Curious George Co-Creator Hans Rey Drew Keystone as Head of Hercules." Earth and Space News. Wednesday, July 9, 2014.
Available @ https://earth-and-space-news.blogspot.com/2014/07/curious-george-co-creator-hans-rey-drew.html

Marriner, Derdriu. "Four Star Keystone Asterism Contains Hercules Globular Cluster." Earth and Space News. Wednesday, Sept. 27, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/09/four-star-keystone-asterism-contains.html

Marriner, Derdriu. "Keystone Asterism Identifies Hercules the Kneeling Hero Constellation." Earth and Space News. Wednesday, Sept. 6, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/09/keystone-asterism-identifies-hercules.html

Molau, Sirko; Jürgen Rendtel. “A Comprehensive List of Meteor Showers Obtained From 10 Years of Observations With the IMO Video Meteor Network.” WGN, vol. 37, no. 4 (August 2009): 98-121.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://articles.adsabs.harvard.edu/full/2009JIMO...37...98M
Available via IMO @ https://www.imo.net/publications/wgn/

Molau, Sirko; Javor Kac. “Results of the IMO Video Meteor Network -- February 2010.” WGN, vol. 38, no. 2 (April 2010): 79-80.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://articles.adsabs.harvard.edu/full/2010JIMO...38...79M
Available via IMO @ https://www.imo.net/publications/wgn/

Molau, Sirko; Javor Jac; Erno Berko; Stefano Crivello; Enrico Stomeo; Antal Igaz. “Results of the IMO Video Meteor Network -- February 2013.” WGN, vol. 41, no. 3 (June 2013): 92-95.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://articles.adsabs.harvard.edu/full/2013JIMO...41...92M
Available via IMO @ https://www.imo.net/publications/wgn/

Molau, Sirko; Javor Jac; Erno Berko; Stefano Crivello; Enrico Stomeo; Antal Igaz; Geert Barentsen; Rui Goncalves. “Results of the IMO Video Meteor Network -- February 2011.” WGN, vol. 39, no. 3 (June 2011): 68-71.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://articles.adsabs.harvard.edu/full/2011JIMO...39...68M
Available via IMO @ https://www.imo.net/publications/wgn/

“Moon Phases February 2019.” Calendar-12.com > Moon Calendar > 2019.
Available @ https://www.calendar-12.com/moon_calendar/2019/february

Ridpath, Ian. “Hercules Continued.” Ian Ridpath > Star Tales.
Available @ http://www.ianridpath.com/startales/hercules2.htm

Wednesday, February 6, 2019

Alpha Centaurids Annually Shower Earth’s Skies Jan. 28 to Feb. 21

Summary: The Alpha Centaurids annually shower Earth’s skies Jan. 28 to Feb. 21, with visibility favoring the Southern Hemisphere and with peak activity Feb. 8.

February alpha Centaurid meteor shower appears to radiate from an area in southeastern Centaurus the Centaur constellation, near the southern constellation’s two brightest stars, Alpha Centauri (α Centauri; Alf Cen, α Cen) and Beta Centauri (β Centauri; Beta Cen, β Cen); Centaurus constellation map credit: IAU and Sky & Telescope (Roger Sinnott and Rick Fienberg; constellation patterns by Alan MacRoberts), CC BY 4.0 International, via IAU (International Astronomical Union)

The Alpha Centaurids annually shower Earth’s skies Jan. 28 to Feb. 21, primarily as a Southern Hemisphere-favoring meteor shower and with peak activity occurring Feb. 8.

The American Meteor Society’s Meteor Activity Outlook weekly columnist, Robert Lunsford, recommends pre-dawn viewing of the Alpha Centaurids. Best viewing in the Southern Hemisphere begins around 5 p.m. local standard time.

The Alpha Centaurid meteor shower disfavors the Northern Hemisphere. Dutch and American astronomer Peter Jenniskens, who is principal investigator at California’s SETI Institute, notes the shower’s lack of visibility in California. Recognized as a meteor expert, Jenniskens describes the shower as known for “annual activity and occasional meteor outbursts.”

Carl Hergenrother, staff scientist with University of Arizona’s Lunar and Planetary Laboratory and member of NASA’s OSIRIS-REX asteroid mission, viewed one Alpha Centaurid meteor on each of two consecutive days in February 2014 via his SALSA3 (Search for Alien Lights Over Southern Arizona) camera in Tucson. The Feb. 2 meteor’s visibility occurred at 7:04 a.m. The next day, Feb. 3, he detected an Alpha Centaurid meteor at 3:48 a.m. Hergenrother’s set up of three meteor surveillance cameras participated in the International Meteor Organization’s Video Meteor Network, run by Germany-based Sirko Molau.

Lunsford describes the Alpha Centaurid shower as producing “mostly swift meteors.” He places entry velocity at 56 kilometers per second (34.79 miles per second).

The shower’s name reflects the radiant (apparent point of origin) of its meteors near Alpha Centauri (α Centauri; Alf Cen, α Cen). The triple star system is located in the southeastern region of Centaurus the Centaur constellation. Alpha Centauri shines as the Centaur’s brightest star, as the night sky’s third brightest star and as the nearest star system outside the solar system.

Alpha Centauri has the traditional name of Rigil Kentaurus. The triple star’s traditional name derives from Arabic for “foot of the Centaur.” Greco-Roman astronomer Claudius Ptolemy (ca. 100-170 CE) describes Alpha Centauri as a first magnitude “star at the tip of the right forefoot” in his second-century, Greek-language, astronomical treatise, the Almagest (Ἡ Μεγάλη Σύνταξις, Hē Megalē Syntaxis, "The Great Treatise").

Centaurus the Centaur solely occupies the Southern Celestial Hemisphere, the southern half of the imaginary sphere projected by astronomy into space. Centaurus lies south of the celestial equator, an imaginary projection of Earth’s equator onto the celestial sphere.

In a July 1994 article in Astronomy and Astrophysics, Peter Jenniskens reported the results of a meteor counting study conducted over 11 years, between 1981 and 1991 by experienced amateur observers in the Netherlands and in Australia. Ten of the study’s 16 counters represented The Dutch Meteor Society (DMS). Six counters represented the North Australian Planetary Observers -- Meteor Section (NAPO-MS).

The study’s effective observing time totaled 4,482 hours. Southern Hemisphere counters accounted for 2,385 hours of observing time. Northern Hemisphere counters contributed 2,097 hours.

The study identified 110,538 meteors. The six observers in Australia enumerated 64,087 meteors. The study’s 10 Netherlands-based participants counted 46,451 meteors.

Over 199 hours of observing time, Australia’s six participants counted 297 Alpha Centaurid stream meteors. Counters placed the geocentric entry velocity of the Alpha Centaurid meteoroids into Earth’s atmosphere at 57 kilometers per second (35.41 miles per second).

The parent body of the Alpha Centaurids is unknown. Jenniskens finds that the shower’s peak times may be suggestive of a short-period Jupiter-type comet.

Carl Hergenrother notes that the unknown parent comet’s meteors display an orbit that is highly inclined to the ecliptic, the sun’s apparent annual path. He places orbital inclination at 107 degrees. The path followed by the shower’s meteors registers orbital perihelion inside Earth’s orbit, at 0.98 astronomical units.

Darkening lunar phases favor about half of the Alpha Centaurid meteor shower’s activity dates. The last quarter moon, offering 44 percent surface visibility Monday, Jan. 28, decreases to waning crescent visibility of 34 percent Tuesday, Jan. 29, slims to 11 percent visibility Friday, Feb. 1, and disappears with the new moon, Monday, Feb. 4. Peak activity coincides with the skimpy waxing crescent phase, with 7 percent visibility Thursday, Feb. 8, and 12 percent Friday, Feb. 8. Surface illumination increases with the first quarter phase Tuesday, Feb. 12, at 46 percent visibility and rises to 100 percent visibility with the full moon Tuesday, Feb. 19.

The International Astronomical Union (IAU), an international association of professional astronomers, is responsible for assigning designations and names to celestial bodies and objects. The IAU recognizes the Alpha Centaurid as 102 ACE.

The takeaways for the Alpha Centaurids, which shower Earth’s skies annually from Jan. 28 to Feb. 21, are that peak activity occurs Feb. 8 and that the shower’s parent body is unknown.

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Triple star system Alpha Centauri’s binary star Alpha Centauri AB comprises Alpha Centauri A (left) and Alpha Centauri B (right): Hubble Telescope’s Wide-Field and Planetary Camera 2 (WFPC2); image credit ESA (European Space Agency)/NASA: NASA Hubble Mission Team Goddard Space Flight Center, "Hubble’s Best Image of Alpha Centauri A and B," NASA article Sep. 2, 2016, Generally not subject to copyright in the United States; may use this material for educational or informational purposes, including photo collections, textbooks, public exhibits, computer graphical simulations and Internet Web pages; general permission extends to personal Web pages, via NASA @ https://www.nasa.gov/image-feature/goddard/2016/hubbles-best-image-of-alpha-centauri-a-and-b

For further information:

“00102 ACE alpha Centaurids.” IAU (International Astronomical Union) Meteor Data Center > List of All Meteor Showers.
Available @ https://www.ta3.sk/IAUC22DB/MDC2007/Roje/pojedynczy_obiekt.php?kodstrumienia=00102&colecimy=&kodmin=00001&kodmax=01032&sortowanie=

Espenak, Fred. “Rigil Kentaurus -- Alpha Centauri.” AstroPixels > Observing Resources Page > Astronomy Information > Additional Links > Star Catalogs > 152 Brightest Stars Through Magnitude 3.00.
Available @ http://astropixels.com/stars/RigelKent-01.html

Garfinkle, Robert. Star-Hopping: Your Visa to Viewing the Universe. Cambridge, England: Cambridge; New York NY; Melbourne, Australia: University Press, 1994.

Hergenrother, Carl. “Beginning of February Meteors.” The Transient Sky -- Comets, Asteroids, Meteors > Archives > February 2014. Feb. 10, 2014.
Available @ https://transientsky.com/2014/02/10/beginning-of-february-meteors/

Hergenrother, Carl. “The Tucson-Based SALSA Meteor Camera.” The Transient Sky -- Comets, Asteroids, Meteors > Archives > August 2009. Aug. 15, 2009.
Available @ https://transientsky.com/2009/08/15/the-tucson-based-salsa-meteor-camera/

Jacchia, Luigi G.; Fred L. Whipple. “Precision Orbits of 413 Photographic Meteors.” Smithsonian Contributions to Astrophysics, vol. 4 (September 1961): 97-129.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://articles.adsabs.harvard.edu/full/1961SCoA....4...97J

Jenniskens, P. (Peter). “Meteor Stream Activity. I. The Annual Streams.” Astronomy and Astrophysics, vol. 287 (1994): 990-1013.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://articles.adsabs.harvard.edu/full/1994A%26A...287..990J

Jenniskens, P. (Peter). “Meteor Stream Activity. II. Meteor Outbursts.” Astronomy and Astrophysics, vol. 295 (1995): 206-235.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://adsabs.harvard.edu/full/1995A%26A...295..206J

Jenniskens, Peter. Meteor Showers and Their Parent Comets. Cambridge, England: Cambridge University Press, 2006.

Jenniskens, Peter; Peter S. Gural; David Holman. “The Established Meteor Showers as Seen in Video Meteoroid Orbit Surveys.” Marc Gyssens and Paul Roggemans, eds., Proceedings of the International Meteor Conference, La Palma, Canary Islands, Spain, 20-23 September 2012. Hove, Belgium: The International Meteor Organization, January 2013.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://articles.adsabs.harvard.edu/full/2013pimo.conf...38J
Available via IMO (International Meteor Organization) @ https://www.imo.net/imcs/imc2012/sites/default/files/jenniskens-1-2012preview.pdf

Kronk, Gary W. “Alpha & Beta Centaurids.” Meteor Showers Online > Meteor Shower Calendar.
Available via Internet Archive Wayback Machine @ https://web.archive.org/web/20071130152917/http://meteorshowersonline.com/showers/alpha-beta_centaurids.html

Lunsford, Robert. Meteors and How to Observe Them. Astronomers’ Observing Guides. New York NY: Springer Science+Business Media, 2009.

McBeath, Alastair. “α-Centaurids (102 ACE).” 2016 Meteor Shower Calendar > 3. January to March: 4.
Available @ https://www.imo.net/files/meteor-shower/cal2015.pdf

“Moon Phases February 2019.” Calendar-12.com > Moon Calendar > 2019.
Available @ https://www.calendar-12.com/moon_calendar/2019/february

“Moon Phases January 2019.” Calendar-12.com > Moon Calendar > 2019.
Available @ https://www.calendar-12.com/moon_calendar/2019/january

Ptolemy (Claudius Ptolemaeus). “Constellation of the Centaur: Configurations.” The Almagest, Book VIII: 257. Translated by R. Catesby Taliaferro. Chicago, IL; London, England; Toronto, Canada; Geneva, Switzerland; Sydney, Australia; Tokyo, Japan; Manila, the Philippines: Encyclopaedia Britannnica, Inc., 1952.

Rendtel, Jürgen. “α-Centaurids (102 ACE).” 2018 Meteor Shower Calendar > 3. January to March: 5.
Available @ https://www.imo.net/files/meteor-shower/cal2018.pdf

Rendtel, Jürgen. “α-Centaurids (102 ACE).” 2017 Meteor Shower Calendar > 3. January to March: 5.
Available @ https://www.imo.net/files/meteor-shower/cal2017.pdf

Rendtel, Jürgen. “α-Centaurids (102 ACE).” 2016 Meteor Shower Calendar > 3. January to March: 5-6.
Available @ https://www.imo.net/files/meteor-shower/cal2016.pdf

Ridpath, Ian. “Centaurus the Centaur.” Ian Ridpath > Star Tales.
Available @ http://www.ianridpath.com/startales/centaurus.htm

Whitworth, N. John. “Alpha Centaurids Meteor Shower.” Universe Guide > Meteor Showers.
Available @ https://www.universeguide.com/meteorshower/alphacentaurids