118401 LINEAR

Last updated
118401 LINEAR
176P/LINEAR
Discovery
Discovered by LINEAR
Discovery date7 September 1999
Designations
(118401) LINEAR
Named after
LINEAR
176P/LINEAR ·1999 RE70
main-belt [1]  · Themis
MBC [2] [3]
Orbital characteristics [1]
Epoch 13 January 2016 (JD 2457400.5)
T_jup = 3.166
Uncertainty parameter 0
Observation arc 5808 days (15.90 yr)
Aphelion 3.8110  AU (570.12  Gm)
Perihelion 2.5793 AU (385.86 Gm)
3.1951 AU (477.98 Gm)
Eccentricity 0.19276
5.71 yr (2086.1 d)
Average orbital speed
16.51 km/s
286.74°
0.17257°/day
Inclination 0.23477°
345.96°
35.460°
Earth  MOID 1.58057 AU (236.450 Gm)
Jupiter  MOID 1.6475 AU (246.46 Gm)
Physical characteristics
Dimensions4.0±0.4 km (Spitzer) [4]
Mass 4.3×1013? kg [5]
Mean density
1.3? g/cm3 (assumed)
Equatorial surface gravity
<0.0017 m/s2
Equatorial escape velocity
<0.0032 km/s
? d
0.06±0.02R [4]
Temperature ~156 K
?
18.19 to 21.91
15.1 [1]
    176P/LINEAR
    Discovery
    Discovered by LINEAR
    Discovery dateOctober 18, 2005
    Designations
    P/1999 RE70
    Orbital characteristics
    Epoch November 6, 2005 (JD 2453680.5)
    Aphelion 3.811678 AU
    Perihelion 2.5811186 AU
    Semi-major axis 3.19640 AU
    Eccentricity 0.1924908
    Orbital period 5.714 a
    Inclination 0.23795°
    Last perihelionNovember 21, 2022 [6]
    2017 March 12 [6]
    June 30, 2011 [7]
    October 18, 2005
    Next perihelion2028-Aug-05 [8]

    118401 LINEAR, provisional designation 1999 RE70, is an asteroid and main-belt comet (176P/LINEAR) [2] [3] that was discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) 1-metre telescopes in Socorro, New Mexico on September 7, 1999. (118401) LINEAR was discovered to be cometary on November 26, 2005, by Henry H. Hsieh and David C. Jewitt as part of the Hawaii Trails project using the Gemini North 8-m telescope on Mauna Kea and was confirmed by the University of Hawaii's 2.2-m (88-in) telescope on December 24–27, 2005, and Gemini on December 29, 2005. Observations using the Spitzer Space Telescope have resulted in an estimate of 4.0±0.4 km for the diameter of (118401) LINEAR. [4]

    The main-belt comets are unique in that they have flat (within the plane of the planets' orbits), approximately circular (small eccentricity), asteroid-like orbits, and not the elongated, often tilted orbits characteristic of all other comets. Because (118401) LINEAR can generate a coma (produced by vapour boiled off the comet), it must be an icy asteroid. When a typical comet approaches the Sun, its ice heats up and sublimates (changes directly from ice to gas), venting gas and dust into space, creating a tail and giving the object a fuzzy appearance. Far from the Sun, sublimation stops, and the remaining ice stays frozen until the comet's next pass close to the Sun. In contrast, objects in the asteroid belt have essentially circular orbits and are expected to be mostly baked dry of ice by their confinement to the inner Solar System (see extinct comet).

    It is suggested that these main-belt asteroid-comets are evidence of a recent impact exposing an icy interior to solar radiation. [2] It is estimated short-period comets remain active for about 10,000 years before having most of their ice sublimated away and going dormant.

    Eight other objects are classified as both periodic comets and numbered asteroids: 2060 Chiron (95P/Chiron), 4015 Wilson–Harrington (107P/Wilson–Harrington), 7968 Elst–Pizarro (133P/Elst–Pizarro), 60558 Echeclus (174P/Echeclus), (323137) 2003 BM80 (282P/2003 BM80), (300163) 2006 VW139 (288P/2006 VW139), (457175) 2008 GO98 (362P/2008 GO98), [9] and (248370) 2005 QN173 (433P/2005 QN173). [10] As a dual-status object, astrometric observations of 118401 LINEAR should be reported under the minor planet designation. [9]

    118401 LINEAR last came to perihelion on 2017 March 12. [6]

    Related Research Articles

    <span class="mw-page-title-main">2060 Chiron</span> Large 200km centaur/comet with 50-year orbit

    2060 Chiron is a small Solar System body in the outer Solar System, orbiting the Sun between Saturn and Uranus. Discovered in 1977 by Charles Kowal, it was the first-identified member of a new class of objects now known as centaurs—bodies orbiting between the asteroid belt and the Kuiper belt.

    <span class="mw-page-title-main">Centaur (small Solar System body)</span> Type of solar system object

    In planetary astronomy, a centaur is a small Solar System body that orbits the Sun between Jupiter and Neptune and crosses the orbits of one or more of the giant planets. Centaurs generally have unstable orbits because they cross or have crossed the orbits of the giant planets; almost all their orbits have dynamic lifetimes of only a few million years, but there is one known centaur, 514107 Kaʻepaokaʻawela, which may be in a stable orbit. Centaurs typically exhibit the characteristics of both asteroids and comets. They are named after the mythological centaurs that were a mixture of horse and human. Observational bias toward large objects makes determination of the total centaur population difficult. Estimates for the number of centaurs in the Solar System more than 1 km in diameter range from as low as 44,000 to more than 10,000,000.

    <span class="mw-page-title-main">4015 Wilson–Harrington</span> Periodic comet with 4 year orbit

    4015 Wilson–Harrington is an active asteroid known both as comet 107P/Wilson–Harrington and as asteroid 4015 Wilson–Harrington. It passed 0.4 AU (60 million km) from Earth on 20 July 2022 and then passed perihelion on 24 August 2022. It seldom gets brighter than apparent magnitude 16. It will return to perihelion on 25 November 2026.

    <span class="mw-page-title-main">7968 Elst–Pizarro</span>

    Comet Elst–Pizarro is a body that displays characteristics of both asteroids and comets, and is the prototype of active asteroids. Its orbit keeps it within the asteroid belt, yet it displayed a dust tail like a comet while near perihelion in 1996, 2001, and 2007.

    8405 Asbolus is a centaur orbiting in the outer Solar System between the orbits of Jupiter and Neptune. It was discovered on 5 April 1995, by James Scotti and Robert Jedicke of Spacewatch (credited) at Kitt Peak Observatory in Arizona, United States. It is named after Asbolus, a centaur in Greek mythology and measures approximately 80 kilometers in diameter.

    <span class="mw-page-title-main">3200 Phaethon</span> Asteroid responsible for the Geminids meteor shower

    3200 Phaethon, provisionally designated 1983 TB, is an active Apollo asteroid with an orbit that brings it closer to the Sun than any other named asteroid. For this reason, it was named after the Greek myth of Phaëthon, son of the sun god Helios. It is 5.8 km (3.6 mi) in diameter and is the parent body of the Geminids meteor shower of mid-December. With an observation arc of 35+ years, it has a very well determined orbit. The 2017 Earth approach distance of about 10 million km was known with an accuracy of ±700 m.

    <span class="mw-page-title-main">596 Scheila</span> Main-belt asteroid

    Scheila is a main-belt asteroid and main-belt comet orbiting the Sun. It was discovered on 21 February 1906 by August Kopff from Heidelberg. Kopff named the asteroid after a female English student with whom he was acquainted.

    <span class="mw-page-title-main">10370 Hylonome</span>

    10370 Hylonome (; prov. designation: 1995 DW2) is a minor planet orbiting in the outer Solar System. The dark and icy body belongs to the class of centaurs and measures approximately 72 kilometers (45 miles) in diameter. It was discovered on 27 February 1995, by English astronomer David C. Jewitt and Vietnamese American astronomer Jane Luu at the U.S. Mauna Kea Observatory in Hawaii, and later named after the mythological creature Hylonome.

    <span class="mw-page-title-main">Active asteroid</span> Bodies orbiting within the main asteroid belt which have shown cometary activity

    Active asteroids are small Solar System bodies that have asteroid-like orbits but show comet-like visual characteristics. That is, they show a coma, tail, or other visual evidence of mass-loss, but their orbits remain within Jupiter's orbit. These bodies were originally designated main-belt comets (MBCs) in 2006 by astronomers David Jewitt and Henry Hsieh, but this name implies they are necessarily icy in composition like a comet and that they only exist within the main-belt, whereas the growing population of active asteroids shows that this is not always the case.

    60558 Echeclus is a centaur, approximately 84 kilometers (52 miles) in diameter, located in the outer Solar System. It was discovered by Spacewatch in 2000 and initially classified as a minor planet with provisional designation 2000 EC98 (also written 2000 EC98). Research in 2001 by Rousselot and Petit at the Besançon observatory in France indicated that it was not a comet, but in December 2005 a cometary coma was detected. In early 2006 the Committee on Small Bodies Nomenclature (CSBN) gave it the cometary designation 174P/Echeclus. It last came to perihelion in April 2015, and was expected to reach about apparent magnitude 16.7 near opposition in September 2015.

    <span class="mw-page-title-main">166P/NEAT</span> Periodic comet with 51 year orbit

    166P/NEAT is a periodic comet and centaur in the outer Solar System. It was discovered by the Near Earth Asteroid Tracking (NEAT) project in 2001 and initially classified a comet with provisional designation P/2001 T4 (NEAT), as it was apparent from the discovery observations that the body exhibited a cometary coma. It is one of few known bodies with centaur-like orbits that display a coma, along with 60558 Echeclus, 2060 Chiron, 165P/LINEAR and 167P/CINEOS. It is also one of the reddest centaurs.

    <span class="mw-page-title-main">Extinct comet</span> Comet that lacks typical activity

    An extinct comet is a comet that has expelled most of its volatile ice and has little left to form a tail and coma. In a dormant comet, rather than being depleted, any remaining volatile components have been sealed beneath an inactive surface layer.

    <span class="mw-page-title-main">354P/LINEAR</span> Small solar system body

    354P/LINEAR, provisionally designated P/2010 A2 (LINEAR), is a small main-belt asteroid that was impacted by another asteroid sometime before 2010. It was discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) at Socorro, New Mexico on 6 January 2010. The asteroid possesses a dusty, comet-like trail of debris that remained for nearly a decade since impact. This was the first time a small-body collision had been observed; since then, minor planet 596 Scheila has also been seen to undergo a collision, in late 2010. The tail is created by millimeter-sized particles being pushed back by solar radiation pressure.

    <span class="mw-page-title-main">238P/Read</span>

    238P/Read is a main-belt comet discovered on 24 October 2005 by astronomer Michael T. Read using the Spacewatch 36-inch telescope on Kitt Peak National Observatory. It has an orbit within the asteroid belt and has displayed the coma of a traditional comet. It fits the definition of an Encke-type comet with.

    <span class="mw-page-title-main">Naming of comets</span>

    Comets have been observed for over 2,000 years. During that time, several different systems have been used to assign names to each comet, and as a result many comets have more than one name.

    <span class="nowrap">(300163) 2006 VW<sub>139</sub></span> Asteroid in the asteroid belt

    (300163) 2006 VW139, provisional designations 2006 VW139 and P/2006 VW139, as well as periodic cometary number 288P, is a kilometer-sized asteroid from the outer regions of the asteroid belt and the first "binary main-belt comet" ever discovered.

    <span class="mw-page-title-main">324P/La Sagra</span>

    324P/La Sagra is an active asteroid with an orbital period of 5.44 years. It has been found to be active in more than one perihelia, indicating that the source of activity is sublimation.

    <span class="nowrap">P/2019 LD<sub>2</sub></span> (ATLAS) Jupiter family comet

    P/2019 LD2 (ATLAS) is a Jupiter-family comet discovered by the Asteroid Terrestrial-impact Last Alert System on 10 June 2019. It was initially reported as the first known Jupiter trojan asteroid to display cometary activity, but its classification as a Jupiter trojan was retracted after closer examination and a longer observation arc revealed its orbit to be unstable like a typical Jupiter family comet and implied that its position near the trojans is temporary.

    <span class="mw-page-title-main">P/2013 R3 (Catalina–PanSTARRS)</span>

    P/2013 R3 (Catalina–PanSTARRS) was an active main-belt asteroid that disintegrated from 2013 to 2014 due to the centrifugal breakup of its rapidly-rotating nucleus. It was discovered by astronomers of the Catalina and Pan-STARRS sky surveys on 15 September 2013. The disintegration of this asteroid ejected numerous fragments and dusty debris into space, which temporarily gave it a diffuse, comet-like appearance with a dust tail blown back by solar radiation pressure. Observations by ground-based telescopes in October 2013 revealed that P/2013 R3 had broken up into four major components, with later Hubble Space Telescope observations showing that these components have further broken up into at least thirteen smaller fragments ranging 100–400 meters (330–1,310 ft) in diameter. P/2013 R3 was never seen again after February 2014.

    <span class="mw-page-title-main">P/2016 J1 (PanSTARRS)</span> Pair of active asteroids

    P/2016 J1 (PanSTARRS) is a pair of active main-belt asteroids that split apart from each other in early 2010. The brightest and largest component of the pair, P/2016 J1-A, was discovered first by the Pan-STARRS 1 survey at Haleakalā Observatory on 5 May 2016. Follow-up observations by the Canada-France-Hawaii Telescope at Mauna Kea Observatory discovered the second component, P/2016 J1-B, on 6 May 2016. Both asteroids are smaller than 1 kilometre (0.62 mi) in diameter, with P/2016 J1-A being roughly 0.6 km (0.37 mi) in diameter and P/2016 J1-B being roughly 0.3 km (0.19 mi) in diameter. The two components recurrently exhibit cometary activity as they approach the Sun near perihelion, suggesting that their activity is driven by sublimation of volatile compounds such as water.

    References

    1. 1 2 3 "JPL Small-Body Database Browser: 118401 LINEAR (1999 RE70)" (2010-11-02 last obs). Retrieved 26 March 2016.
    2. 1 2 3 Henry H. Hsieh (May 2010). "Main Belt Comets". Hawaii. Archived from the original on 2011-08-06. Retrieved 2010-12-15. (older 2010 site) Archived 2009-08-10 at the Wayback Machine
    3. 1 2 David Jewitt. "Main Belt Comets". UCLA, Department of Earth and Space Sciences. Retrieved 2010-12-15.
    4. 1 2 3 Hsieh, Henry H.; Jewitt, David C.; Fernández, Yanga R. (2009). "Albedos of Main-Belt Comets 133P/ELST-PIZARRO and 176P/LINEAR". The Astrophysical Journal Letters. 694 (2): L111–L114. arXiv: 0902.3682 . Bibcode:2009ApJ...694L.111H. doi:10.1088/0004-637X/694/2/L111. S2CID   17438376.
    5. Using a spherical radius of 2 km; volume of a sphere * an assumed density of 1.3 g/cm3 yields a mass (m=d*v) of 4.3E+13 kg
    6. 1 2 3 "176P/LINEAR Orbit". Minor Planet Center . Retrieved 2017-04-09.
    7. Syuichi Nakano (2006-10-29). "176P/LINEAR = (118401) 1999 RE70 (NK 1373)". OAA Computing and Minor Planet Sections. Retrieved 2012-02-25.
    8. "Horizons Batch for 118401 LINEAR (1999 RE70 on 2028-Aug-05" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons . Retrieved 2023-05-01. (JPL#73/Soln.date: 2023-Apr-27)
    9. 1 2 "Dual-Status Objects". Minor Planet Center. 2008-03-06. Retrieved 2018-02-13.
    10. M.P.C. 133823
    Numbered comets
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