C/2015 ER61 (PanSTARRS)
{{Short description|Oort cloud comet}}
{{DISPLAYTITLE:{{mp|C/2015 ER|61}} (PanSTARRS)}}
{{Use dmy dates|date=April 2020}}
{{Infobox comet
| name = C/{{mp|2015 ER|61}} (PanSTARRS)
| image = Le_Pleiadi_e_la_cometa_PanSTARRS_C_2015ER61_crop.jpg
| caption = Comet PanSTARRS and the Pleiades cluster photographed from Italy on 22 August 2017
| discoverer = Pan-STARRS 1 (F51)
| discovery_date = 15 March 2015
| designations =
| epoch = 7 May 2017 (JD 2457880.5)
| observation_arc =1.96 yr
| obs =
| orbit =
| aphelion = {{Ubl
| {{Val|2456|62|u=AU}}
| 1425/854 AU{{ref|2}}
}}
| perihelion = 1.0421 AU
| semimajor = {{Ubl
| {{Val|1229|31|u=AU}}
| 715/428 AU{{ref|1}}
}}
| semiminor =
| orbital_circ =
| eccentricity = 0.99730
| period = {{Ubl
| 9000 years (epoch 2050)
}}
| avg_speed =
| max_speed =
| min_speed =
| inclination = 6.3490°
| asc_node = 235.21°
| arg_peri = 68.197°
| long_peri =
| tjup =
|Mars_moid = <0.00005 AU{{cite web |last1=Gray |first1=Bill |title=Find_Orb Orbit Determination Software |url=https://www.projectpluto.com/find_orb.htm |website=Project PLuto |access-date=22 April 2019}}
| physical_ref = {{r|Jewitt_2022}}
| dimensions = {{cvt|2.6|–|2.8|km|mi}}
| mean_diameter = {{cvt|2.75|km|mi}}
| M1 = 14.74
| M2 =
}}
C/{{mp|2015 ER|61}} (PanSTARRS) is a comet and inner Oort cloud object. When classified as a minor planet, it had the fourth-largest aphelion of any known minor planet in the Solar System, after {{mpl|2005 VX|3}}, {{mpl|2012 DR|30}}, and {{mpl|2013 BL|76}}. It additionally had the most eccentric orbit of any known minor planet, with its distance from the Sun varying by about 99.9% during the course of its orbit, followed by {{mpl|2005 VX|3}} with an eccentricity of 0.9973. On 30 January 2016, it was classified as a comet when it was 5.7 AU from the Sun. It comes close to Jupiter, and a close approach in the past threw it on the distant orbit it is on now.
Though the comet nucleus was probably mildly active, early asteroidal estimates gave an absolute magnitude (H) of 12.3, which would suggest a nucleus as large as 8–20 km in diameter. But it could easily be half that size due to activity brightening the nucleus.
2017 perihelion
C/{{mp|2015 ER|61}} was discovered on 15 March 2015 when it was 8.44 AU from the Sun, and magnitude 21.5. By early February 2016, the object reached magnitude 20, and made a close approach to Jupiter on 28 March 2016 of 0.9245 AU. This changed its orbit, significantly decreasing its aphelion distance from 1430 AU to ~1200 AU, and as it passed through the inner Solar System its aphelion decreased to 770 AU, and by 2020 it had an aphelion of 854 AU.
The barycentric orbital period will decrease from 19000 years (epoch 1950) to 9000 years (epoch 2050).
As of January 2017, it was magnitude 13, and increasing in brightness. On 4 April 2017, it was detected outbursting to magnitude 6.5. On 19 April 2017, it reached its closest point to Earth of ~1.2 AU. At this point, it was about apparent magnitude 8, and, assuming a size of 20 km, have an apparent size of 19 mas. It came to perihelion (closest approach to the Sun) on 10 May 2017. It will not be 50 AU from the Sun until 2045.
Orbital elements table
| class="wikitable" style="text-align: center;"
! width= 70|Dist. ! width= 80|Event ! width= 85|Epoch ! width= 60|Aphelion ! width= 60|Perihelion ! width=100|Semi-major axis ! width= 60|Eccentricity ! width= 60|Period ! width= 60|Inclination ! width=170|Longitude ascending node ! width=100|Mean anomaly ! width=150|Argument of perihelion | ||||||||||
| (AU)
! ! !colspan=3|(AU) ! ! (years) !colspan=4| (°) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| align=center
! 36.5 | | 2000-01-01 | 1423.4 | 1.05378 | 712.2 | 0.99852 | 18,990 | 6.12745 | 239.06 | 359.671 | 63.99 |
| 20.2
| || 2010-01-01 || 1435.4 || 1.05377 || 718.2 || 0.99853 || 19,240 || 6.12732 || 239.03 || 359.862 || 64.01 | ||||||||||
| 9.01
| || 2015-01-01 || 1430.8 || 1.05347 || 715.9 || 0.99853 || 19,140 || 6.12819 || 238.97 || 359.956 || 64.08 | ||||||||||
| 8.44
| discovery || 2015-03-15 || 1436.1 || 1.05313 || 718.6 || 0.99853 || 19,250 || 6.12879 || 238.95 || 359.960 || 64.11 | ||||||||||
| 6.00
| || 2016-01-01 || 1667.3 || 1.04763 || 834.2 || 0.99874 || 24,080 || 6.15827 || 238.25 || 359.980 || 64.92 | ||||||||||
| 5.204
| Jupiter approach || 2016-03-28 || 1291.9 || 1.04030 || 646.5 || 0.99839 || 16,420 || 6.24250 || 236.73 || 359.976 || 66.64 | ||||||||||
| 2.242
| || 2017-01-01 || 324.6 || 1.03505 || 162.8 || 0.99364 || 2,080 || 6.34928 || 235.27 || 359.939 || 68.46 | ||||||||||
| 1.079
| Earth approach || 2017-04-04 || 164.3 || 1.03830 || 82.7 || 0.98744 || 750 || 6.34595 || 235.27 || 359.953 || 68.30 | ||||||||||
| 1.0397
| Perihelion || 2017-05-10 || 210.0 || 1.03973 || 105.5 || 0.99015 || 1,080 || 6.34423 || 235.25 || 0.0004 || 67.92 | ||||||||||
| 3.437
| || 2018-01-01 || 1091.1 || 1.04449 || 546.1 || 0.99809 || 12,750 || 6.34438 || 235.23 || 0.018 || 68.27 | ||||||||||
| 9.78
| || 2020-01-01 || 857.8 || 1.04583 || 429.4 || 0.99756 || 8,890 || 6.34009 || 235.21 || 0.107 || 68.29 | ||||||||||
| 56.03
| || 2050-01-01 || 854.6 || 1.04649 || 427.8 || 0.99755 || 8,840 || 6.33543 || 235.18 || 1.329 || 68.34 |
Comparison
File:Celestia distant object orbits.png, {{mpl|2005 VX|3}}, {{mpl-|308933|2006 SQ|372}}, {{mpl|2007 TG|422}}, {{mpl|2007 DA|61}}, {{mpl-|418993|2009 MS|9}}, {{mpl|2010 GB|174}}, {{mpl-|336756|2010 NV|1}}, {{mpl|2010 BK|118}}, {{mpl|2012 DR|30}}, {{mpl|2012 VP|113}}, {{mpl|2013 BL|76}}, {{mpl|2013 AZ|60}}, {{mpl|2013 RF|98}}, {{mpl|2015 ER|61}}]]
{{clear}}
See also
Notes
{{note|1}}{{note|2}} Because {{mp|2015 ER|61}}'s orbit takes it so far from the Sun, a more accurate value for its orbit is a barycentric solution. Additionally, a close approach to Jupiter in 2016, and a travel through the inner solar system in 2017 drastically changes its orbit. Therefore, orbits for 2000–2016 and 2018–2100 are provided, respectively.
References
{{reflist|refs=
|title=C/2015 ER61 (PANSTARRS) Orbit
|publisher=Minor Planet Center
|url=http://minorplanetcenter.net/db_search/show_object?object_id=C%2F2015+ER61
|archive-url=https://archive.today/20170302175326/http://minorplanetcenter.net/db_search/show_object?object_id=C/2015+ER61
|archive-date=2017-03-02
|url-status=live
|access-date=2017-03-02
}}
|type=last observation: 2016-01-23; arc: 1 yr
|title=JPL Small-Body Database Browser: (2015 ER61)
|url=https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=c%2F2015%20er61
|archive-url=https://archive.today/20150624171448/http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2015ER61;cad=1
|archive-date=2015-06-24
|url-status=live
|publisher=Jet Propulsion Laboratory
}}
|title=MPEC 2016-C01 : COMET C/2015 ER61 (PANSTARRS)
|publisher=IAU Minor Planet Center
|date=2016-02-01
|url=http://www.minorplanetcenter.net/mpec/K16/K16C01.html
|access-date=2016-02-01}} (CK15E61R)
|date=2007-02-27
|title=C/2015 ER61 ( PanSTARRS )
|publisher=Seiichi Yoshida's Comet Catalog
|author=Seiichi Yoshida
|url=http://www.aerith.net/comet/catalog/2015ER61/2015ER61.html
|access-date=2017-03-02}}
|title=Watching a Long Period Comet Turn On - C/2015 ER61 (PANSTARRS)
|bibcode=2016DPS....4830806M|last1=Meech|first1=Karen Jean|last2=Sorli|first2=Kya|last3=Kleyna|first3=Jan|last4=Keane|first4=Jacqueline|last5=Bauer|first5=James M.|last6=Micheli|first6=Marco|last7=Schambeau|first7=Charles Alfred|last8=Sarid|first8=Gal|last9=Hainaut|first9=Olivier|last10=Yang|first10=Bin|last11=Wainscoat|first11=Richard J.|last12=Boe|first12=Benjamin|last13=Kramer|first13=Emily A.|last14=Bhatt|first14=Bhuwan|last15=Sahu|first15=Devendra|journal=AAS/Division for Planetary Sciences Meeting Abstracts #48|year=2016|volume=48|pages=308.06}}
| author1= D. C. Jewitt
| title= Destruction of Long-period Comets
| url= https://iopscience.iop.org/article/10.3847/1538-3881/ac886d/pdf
| journal= Astronomical Journal
| year= 2022
| volume= 164
| issue= 4
| pages= 158–166
| bibcode= 2022AJ....164..158J
| arxiv= 2208.04469
| doi= 10.3847/1538-3881/ac886d
| doi-access= free }}
}}
External links
- {{JPL small body|id=C/2015 ER61}}
{{Small Solar System bodies}}
{{Comets}}
{{2015 in space}}
{{2017 in space}}
{{Authority control}}
{{DEFAULTSORT:PANSTARRS, 2015 ER61}}