C/2017 U7 (PanSTARRS)
Discovery [1][2] | |
---|---|
Discovered by | Pan-STARRS |
Discovery site | Haleakala Obs. |
Discovery date | 29 October 2017 |
Designations | |
C/2017 U7 | |
P10EwQh, A/2017 U7 | |
hyperbolic comet [3] | |
Orbital characteristics [3] | |
Epoch 29 November 2017 (JD 2458086.5) | |
Uncertainty parameter n.a. | |
Observation arc | 176 days |
Earliest precovery date | 18 August 2017[1] |
Perihelion | 6.4187±0.0008 |
−3700±300 | |
Eccentricity | 1.0018±0.0001 1.000008 (Barycentric epoch 2200)[4] |
~800000 years (inbound barycentric epoch 2000) | |
n.a. | |
0° 0m 0.016s / day | |
Inclination | 142.6390° |
276.217° | |
325.95° | |
Earth MOID | 5.468 |
Jupiter MOID | 1.635 |
Physical characteristics | |
Dimensions | 13.5–59 km (assumed)[5] |
20.6 (March 2018) | |
10.6±0.62 | |
C/2017 U7 (PanSTARRS) is a hyperbolic comet (previously classified as A/2017 U7, a hyperbolic asteroid), first observed on 29 October 2017 by astronomers of the Pan-STARRS facility at Haleakala Observatory, Hawaii, United States when the object was 7.8
Orbit
[edit]Although C/2017 U7's orbit is no longer bound to the Solar System, unlike ʻOumuamua, it is probably not an interstellar object. It had an inbound orbital period of roughly 800000 years. Its point of origin is inclined only 3.5 degrees from the galactic plane, but its aphelion points roughly to the Galactic anticenter, so if it did somehow originate from interstellar space with a typical Solar System velocity (which is highly unlikely) it would have been traveling on an unusual orbit directly into the galactic core from beyond the Sun's orbit around the Milky Way.[citation needed]
A barycentric orbit of C/2017 U7, however, shows that it is only a very distant Solar System object, approaching as far as 16,000 ± 1,000
As of March 2018[update], C/2017 U7 is inbound 7.4
-
Path across sky
-
Hyperbolic trajectory through solar system
Physical characterization
[edit]The spectra and the colors of the hyperbolic comet C/2017 U7 (PANSTARRS) are atypical and the feature and overall spectral shape can be reproduced by laboratory spectra of kerite, a template for aliphatic-rich hydrocarbons that has been previously identified in NIR cometary spectra absorptions.[9]
Notes
[edit]- ^ Objects on hyperbolic trajectories have negative semimajor axis, giving them a positive orbital energy.
- ^ Soln.date: 2018-Mar-04: EC= 1.000008 (Barycentric epoch 2200) Using a heliocentric orbit allows Jupiter's 12 year orbit to drop the eccentricity below 1 centered around the years 2042, 2054, 2066, etc. For example in July 2042 the heliocentric eccentricity is 0.99927.
- ^ Soln.date: 2018-Mar-04: EC= 1.003046 (Heliocentric epoch 2020-May-19)
References
[edit]- ^ a b c "A/2017 U7". Minor Planet Center. Retrieved 5 March 2018.
- ^ a b c "MPEC 2018-E17 : A/2017 U7". IAU Minor Planet Center. 4 March 2018. Retrieved 4 March 2018. (AK17U070)
- ^ a b c d "JPL Small-Body Database Browser: (A/2017 U7)" (2018-02-10 last obs.). Jet Propulsion Laboratory. Archived from the original on 5 March 2018. Retrieved 5 March 2018.
- ^ a b c Horizons output. "Barycentric Osculating Orbital Elements for Asteroid (A/2017 U7)". JPL Solar System Dynamics. Retrieved 5 March 2018. (Solution using the Solar System's Barycenter. Select Ephemeris Type: Elements and Center: @0)
- ^ a b "Asteroid Size Estimator". Jet Propulsion Laboratory. Retrieved 5 March 2018.
- ^ "JPL Small-Body Database Search Engine: orbital class Hyperbolic Asteroid (HYA)". Jet Propulsion Laboratory Solar System Dynamics. Retrieved 12 August 2018.
- ^ de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl; Aarseth, Sverre J. (6 February 2018). "Where the Solar system meets the solar neighbourhood: patterns in the distribution of radiants of observed hyperbolic minor bodies". Monthly Notices of the Royal Astronomical Society Letters. 476 (1): L1–L5. arXiv:1802.00778. Bibcode:2018MNRAS.476L...1D. doi:10.1093/mnrasl/sly019.
- ^ Plait, Phil (6 March 2018). "AN ASTEROID IS ABOUT TO EMBARK ON A VERY LONG VOYAGE TO INTERSTELLAR SPACE". SyFyWire. Retrieved 6 March 2018.
- ^ a b Santana, Marçal Evangelista; Carvano, Jorge M.; de Prá, Mario; de la Fuente Marcos, Raúl; Schambeau, Charles; Licandro, Javier; de la Fuente Marcos, Carlos; Souza-Feliciano, Ana Carolina; Pinilla-Alonso, Noemi (1 May 2022). "Physical and dynamical characterization of hyperbolic comet C/2017 U7 (PANSTARRS)". Icarus. 377 (1): 114834. Bibcode:2022Icar..37714834E. doi:10.1016/j.icarus.2021.114834. S2CID 246093558.
External links
[edit]- C/2017 U7 at the JPL Small-Body Database