C / 2013 R1 (Lovejoy)

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C / 2013 R1 (Lovejoy) [i]
C / 2013 R1 on November 28, 2013
C / 2013 R1 on November 28, 2013
Properties of the orbit ( animation )
Epoch:  December 29, 2013 ( JD 2,456,655.5)
Orbit type long-period
Numerical eccentricity 0.99842
Perihelion 0.812 AU
Aphelion 1030 AU
Major semi-axis 515.4 AU
Sidereal period ~ 11700  a
Inclination of the orbit plane 64.0 °
Perihelion December 22, 2013
Orbital velocity in the perihelion 46.7 km / s
history
Explorer Terry Lovejoy
Date of discovery September 7, 2013
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . Please also note the note on comet articles .

C / 2013 R1 (Lovejoy) is a comet that was observed in 2013 and 2014.

Discovery and observation

The Australian amateur astronomer Terry Lovejoy , who had previously found three comets, discovered this comet in several images of his 20 cm telescope , which he took on September 7 and 8, 2013. The comet at this time had a brightness of about 14 mag and was located in the constellation Orion . First estimates suggested a brightness of 8 may be expected for the time of its approach to the sun and earth , so the comet would have remained a telescopic object.

However, its brightness developed unusually strongly and it could be seen with the naked eye for the first time at the beginning of November . By the end of November the comet's brightness rose to around 4.5 mag and then slowly decreased again. In the middle of December a tail 2-3 ° long could be observed. At the end of January 2014 the brightness was 7 mag, the comet was observed telescopically until September 2014.

During the visibility of comet Lovejoy, three other similarly bright comets with brightnesses between 8 and 10 mag could be observed in the morning sky, so comet Lovejoy and comet C / 2012 S1 (ISON) were on earth for observers on December 19th 2013 only at an angular distance of about 9.5 ° from each other. On February 7, 2014, Comet Lovejoy even approached Comet C / 2012 X1 (LINEAR) to an angular distance of about 2.1 °, so that both could be observed together in binoculars. The short-period comet 2P / Encke , on the other hand, was far away in the sky on February 10 with a smallest angular distance of about 44 °.

Scientific evaluation

With the 30 m radio telescope of the Institute for Radio Astronomy in the millimeter range (IRAM), the presence of molecules such as HCN , HNC and methanol in the coma was detected. With the same radio telescope, in another experiment, ethylene glycol and formamide were also detected in a concentration similar to that of C / 1995 O1 (Hale-Bopp) . In addition, was formic acid and acetaldehyde found. The Onsala Space Observatory also measured the production rate and relative abundance of HCN compared to water .

With the HARPS-N Échelle spectrograph on the 3.5 m telescope Telescopio Nazionale Galileo , high-resolution spectra were obtained with which the production rates of C 2 and NH 2 were measured and the ratio of the isotopes 12 C / 13 C and 14 N / 15 N could be determined. Similar measurements were also carried out with the high-resolution spectrograph WINERED at the 1.3 m Araki telescope of the Koyama Astronomical Observatory in Kyoto .

With the 0.6 m Trappist telescope ( TRAnsiting Planets and PlanetesImal Small Telescope ) of the La Silla Observatory of the European Southern Observatory in Chile , the outgassing rate of molecules such as OH, NH, CN, C 3 and C 2 , as well as the production rate of dust was measured. The production rates and other parameters of various gases in the cometary coma were also examined with the NIRSPEC (Near Infra-Red Spectrograph) at the Keck Observatory on Mauna Kea . It was found that the comet Lovejoy is particularly rich in carbon monoxide .

With the Solar Wind Anisotropies (SWAN) camera on board the Solar and Heliospheric Observatory (SOHO) recordings were made, from which the production rate of water depending on the distance from the sun of the comet was derived.

Polarimetric measurements of the comet were carried out at the National Astronomical Observatory Rožen in Bulgaria .

Orbit

For the comet, an elongated elliptical orbit could be determined from 3781 observation data over a period of just over a year , which is inclined by around 64 ° to the ecliptic . The comet's orbit is thus inclined to the planets of the planets . At the point closest to the Sun ( perihelion ), which the comet passed on December 22, 2013, it was about 121.5 million km from the Sun and was in the area between the orbits of Venus and Earth.

During its flight through the inner solar system , the comet managed to avoid closer approaches to almost all planets. It did not get significantly close to Mars and Mercury , only it approached Earth on November 19, 2013 to around 0.40  AU / 59.3 million km and on December 5 it passed Venus in around 100.1 million. km distance.

In the vicinity of the ascending node of its orbit, the comet even approached the earth's orbit to about 0.15 AU / 21.9 million km around November 10, 2013  , but the earth did not reach this point of its orbit until December 3 .

According to the orbital elements , which are afflicted with a certain uncertainty , and without taking into account non-gravitational forces on the comet, its orbit before its approach to the inner solar system still had an eccentricity of about 0.99777 and a semi-major axis of about 363 AU, so that its orbital period was about 6920 years. Due to the gravitational pull of the planets, in particular due to the relatively close passages of Jupiter on September 29, 2013 in about 4 AU distance and on Saturn on November 24, 2015 in about 5 ½ AU distance, its orbital eccentricity was reduced to about 0.99806 and its semi-major axis enlarged to about 418 AU, so that its orbital period increases to about 8540 years.

According to the orbital elements, as stated by S. Yoshida on his homepage, and which also take non-gravitational forces into account, the values ​​for the original and future orbit would be slightly different, if the comet's orbit would still have been before its approach to the inner solar system had an eccentricity of about 0.99779 and a semi-major axis of about 366 AU, so that its orbital period would have been about 7010 years. Its future orbit would have an orbital eccentricity of about 0.99803 and a semi-major axis of about 410 AU, so its orbital period would be about 8300 years.

See also

Web links

Commons : C / 2013 R1  - Collection of Images, Videos and Audio Files

Individual evidence

  1. ↑ José J. Chambó: C / 2013 R1 Lovejoy. In: Cometografía. May 29, 2014, accessed July 16, 2020 (Spanish).
  2. ^ Comet Lovejoy C / 2013 R1. In: kometen.info. February 22, 2014, accessed July 16, 2020 .
  3. ↑ M. Agúndez, N. Biver, P. Santos-Sanz, D. Bockelée-Morvan, R. Moreno: Molecular observations of comets C / 2012 S1 (ISON) and C / 2013 R1 (Lovejoy): HNC / HCN ratios and upper limits to PH 3 . In: Astronomy & Astrophysics. Volume 564, L2, 2014, pp. 1–5 doi: 10.1051 / 0004-6361 / 201423639 . ( PDF; 286 kB )
  4. ↑ N. Biver, D. Bockelée-Morvan, V. Debout, J. Crovisier, J. Boissier, DC Lis, N. Dello Russo, R. Moreno, P. Colom, G. Paubert, R. Vervack, HA Weaver: Complex organic molecules in comets C / 2012 F6 (Lemmon) and C / 2013 R1 (Lovejoy): detection of ethylene glycol and formamide. In: Astronomy & Astrophysics. Volume 566, L5, 2014, pp. 1–5 doi: 10.1051 / 0004-6361 / 201423890 . ( PDF; 205 kB )
  5. ↑ ES Wirström, MS Lerner, P. Källström, A. Levinsson, A. Olivefors, E. Tegehall: HCN observations of comets C / 2013 R1 (Lovejoy) and C / 2014 Q2 (Lovejoy). In: Astronomy & Astrophysics. Volume 588, A72, 2016, pp. 1–4 doi: 10.1051 / 0004-6361 / 201527482 . ( PDF; 187 kB )
  6. ^ P. Rousselot, A. Decock, PP Korsun, E. Jehin, I. Kulyk, J. Manfroid, D. Hutsemékers: High-resolution spectra of comet C / 2013 R1 (Lovejoy). In: Astronomy & Astrophysics. Volume 580, A3, 2015, pp. 1–5 doi: 10.1051 / 0004-6361 / 201526173 . ( PDF; 128 kB )
  7. ↑ Y. Shinnaka, H. Kawakita, S. Kondo, Y. Ikeda, N. Kobayashi, S. Hamano, H. Sameshima, K. Fukue, N. Matsunaga, C. Yasui: Near-infrared Spectroscopic Observations of Comet C / 2013 R1 (Lovejoy) by WINERED: CN Red-system Band Emission. In: The Astronomical Journal. Volume 154, No. 2, 2017, pp. 1-15 doi: 10.3847 / 1538-3881 / aa7576 . ( PDF; 923 kB )
  8. ↑ C. Opitom, E. Jehin, J. Manfroid, D. Hutsemékers, M. Gillon, P. Magain: TRAPPIST photometry and imaging monitoring of comet C / 2013 R1 (Lovejoy): Implications for the origin of daughter species. In: Astronomy & Astrophysics. Volume 584, A122, 2015, pp. 1–10 doi: 10.1051 / 0004-6361 / 201526427 . ( PDF; 2.29 MB )
  9. ↑ L. Paganini, MJ Mumma, GL Villanueva, JV Keane, GA Blake, BP Bonev, MA DiSanti, EL Gibb, KJ Meech: C / 2013 R1 (Lovejoy) at IR Wavelengths and the Variability of CO Abundances among Oort Cloud Comets. In: The Astrophysical Journal. Volume 791, No. 2, 2014, pp. 1–8 doi: 10.1088 / 0004-637X / 791/2/122 . ( PDF; 809 kB )
  10. ↑ MR Combi, TT Mäkinen, J.-L. Bertaux, E. Quémerais, S. Ferron, M. Avery, C. Wright: Water production activity of nine long-period comets from SOHO / SWAN observations of hydrogen Lyman-alpha: 2013–2016. In: Icarus. Volume 300, 2018, pp. 33-46 doi: 10.1016 / j.icarus.2017.08.035 .
  11. ↑ G. Borisov, S. Bagnulo, P. Nikolov, T. Bonev: Imaging polarimetry and spectropolarimetry of comet C / 2013 R1 (Lovejoy). In: Planetary and Space Science. Volume 118, 2015, pp. 187–192 doi: 10.1016 / j.pss.2015.06.012 .
  12. ↑ C / 2013 R1 (Lovejoy) in the Small-Body Database of the Jet Propulsion Laboratory (English).Template: JPL Small-Body Database Browser / Maintenance / Alt
  13. ↑ S. Yoshida: C / 2013 R1 (Lovejoy). In: Seiichi Yoshida's homepage. June 11, 2016, accessed on July 16, 2020 .
  14. ↑ SOLEX 12.1 by A. Vitagliano. Retrieved July 9, 2020 .