Atira asteroid
Atira asteroids
History
Naming
There is no official name for the class commonly referred as Atira asteroids. The term "Apohele asteroids" was proposed by the discoverers of 1998 DK36,[3] after the Hawaiian word for orbit, from apo [ˈɐpo] 'circle' and hele [ˈhɛlɛ] 'to go'.[4] This was suggested partly because of its similarity to the words aphelion (apoapsis) and helios.[a] Other authors adopted the designation "Inner Earth Objects" (IEOs).[5] Following the general practice to name a new class of asteroids for the first recognized member of that class, which in this case was 163693 Atira, the designation of "Atira asteroids" was largely adopted by the scientific community, including by NASA.[6][1]
Discovery and observation
Their location inside the Earth's orbit makes Atiras very difficult to observe, as from Earth's perspective they are close to the
The first suspected Atira asteroid was 1998 DK36, which was discovered by
Origins
Most Atira asteroids originated in the asteroid belt and were driven to their current locations as a result of gravitational perturbation, as well as other causes such as the Yarkovsky effect.[7] A number of known Atiras could be fragments or former moons of larger Atiras as they exhibit an unusually high level of orbital correlation.[11]
Orbits
Atiras do not cross Earth's orbit and are not immediate impact event threats, but their orbits may be perturbed outward by a close approach to either Mercury or Venus and become Earth-crossing asteroids in the future. The dynamics of many Atira asteroids resemble the one induced by the Kozai-Lidov mechanism,[b] which contributes to enhanced long-term orbital stability, since there is no libration of the perihelion.[12][13]
Exploration
A 2017 study published in the journal
Related asteroid groups
ꞌAylóꞌchaxnim asteroids
ꞌAylóꞌchaxnim asteroids, which had been provisionally nicknamed "Vatira" asteroids before the first was discovered,[c] are a subclass of Atiras that orbit entirely interior to the orbit of Venus, aka 0.718 AU.[16] Despite their orbits placing them at a significant distance from Earth, they are still classified as near-Earth objects.[17] Observations suggest that ꞌAylóꞌchaxnim asteroids frequently have their orbits altered into Atira asteroids and vice-versa.[18]
First formally theorised to exist by William F. Bottke and Gianluca Masi in 2002 and 2003,[19][20] the first and to date only such asteroid found is 594913 ꞌAylóꞌchaxnim,[21][22] which was discovered on 4 January 2020 by the Zwicky Transient Facility. As the archetype, it subsequently gave its name to the class.[16] It has an aphelion of only 0.656 AU, making it the asteroid with the smallest known aphelion.[8][12]
Vulcanoids
No asteroids have yet been discovered to orbit entirely inside the orbit of
Members
The following table lists the known and suspected Atiras as of November 2023[update]. 594913 ꞌAylóꞌchaxnim, due to its unique classification, has been highlighted in pink. The interior planets Mercury and Venus have been included for comparison as grey rows.
Designation | AU )
|
Semi-major axis (AU) |
Aphelion (AU) |
Eccentricity
|
Inclination )
(° |
Period (days) |
Observation arc (days) |
(H) | Diameter(A) ( m )
|
Discoverer | Ref |
---|---|---|---|---|---|---|---|---|---|---|---|
Mercury (for comparison) |
0.307 | 0.3871 | 0.467 | 0.2056 | 7.01 | 88 | NA | −0.6 | 4,879,400 | NA | |
Venus (for comparison) |
0.718 | 0.7233 | 0.728 | 0.0068 | 3.39 | 225 | NA | −4.5 | 12,103,600 | NA | |
1998 DK36 | 0.404 | 0.6923 | 0.980 | 0.4160 | 2.02 | 210 | 1 | 25.0 | 35 | David J. Tholen | MPC · JPL |
163693 Atira | 0.502 | 0.7410 | 0.980 | 0.3222 | 25.62 | 233 | 6601 | 16.3 | 4800±500(B) | LINEAR | List MPC · JPL |
(164294) 2004 XZ130 | 0.337 | 0.6176 | 0.898 | 0.4546 | 2.95 | 177 | 3564 | 20.4 | 300 | David J. Tholen | List MPC · JPL |
(434326) 2004 JG6 | 0.298 | 0.6353 | 0.973 | 0.5311 | 18.94 | 185 | 6227 | 18.5 | 710 | LONEOS | List MPC · JPL |
(413563) 2005 TG45 | 0.428 | 0.6814 | 0.935 | 0.3722 | 23.33 | 205 | 5814 | 17.6 | 1,100 | Catalina Sky Survey | List MPC · JPL |
2006 KZ39 ) |
0.262 | 0.6008 | 0.940 | 0.5641 | 10.76 | 170 | 5110 | 20.1 | 340 | Mount Lemmon Survey Pan-STARRS |
MPC · JPL |
(613676) 2006 WE4 | 0.641 | 0.7848 | 0.928 | 0.1829 | 24.77 | 254 | 4995 | 18.9 | 590 | Mount Lemmon Survey | List MPC · JPL |
(418265) 2008 EA32 | 0.428 | 0.6159 | 0.804 | 0.3050 | 28.26 | 177 | 4794 | 16.5 | 1,800 | Catalina Sky Survey | List MPC · JPL |
(481817) 2008 UL90 | 0.431 | 0.6951 | 0.959 | 0.3798 | 24.31 | 212 | 4496 | 18.6 | 680 | Mount Lemmon Survey | List MPC · JPL |
2010 XB11 | 0.288 | 0.6180 | 0.948 | 0.5339 | 29.89 | 177 | 1811 | 19.9 | 370 | Mount Lemmon Survey | MPC · JPL |
2012 VE46 | 0.455 | 0.7131 | 0.971 | 0.3613 | 6.67 | 220 | 2225 | 20.2 | 320 | Pan-STARRS | MPC · JPL |
2013 TQ5 | 0.653 | 0.7737 | 0.894 | 0.1557 | 16.40 | 249 | 2269 | 19.8 | 390 | Mount Lemmon Survey | MPC · JPL |
2014 FO47 | 0.548 | 0.7522 | 0.956 | 0.2712 | 19.20 | 238 | 2779 | 20.3 | 310 | Mount Lemmon Survey | MPC · JPL |
2015 DR215 | 0.352 | 0.6665 | 0.981 | 0.4716 | 4.08 | 199 | 2156 | 20.4 | 300 | Pan-STARRS | MPC · JPL |
2017 XA1 | 0.646 | 0.8095 | 0.973 | 0.2017 | 17.18 | 266 | 1084 | 21.3 | 200 | Pan-STARRS | MPC · JPL |
2017 YH (aka 2016 XJ24) |
0.328 | 0.6343 | 0.940 | 0.4825 | 19.85 | 185 | 1127 | 18.4 | 740 | Spacewatch ATLAS |
MPC · JPL |
2018 JB3 | 0.485 | 0.6832 | 0.882 | 0.2904 | 40.39 | 206 | 2037 | 17.7 | 1,020 | Catalina Sky Survey | MPC · JPL |
2019 AQ3 | 0.404 | 0.5887 | 0.774 | 0.3143 | 47.22 | 165 | 2175 | 17.5 | 1,120 | Zwicky Transient Facility | MPC · JPL |
2019 LF6 | 0.317 | 0.5554 | 0.794 | 0.4293 | 29.51 | 151 | 796 | 17.3 | 1,230 | Zwicky Transient Facility | MPC · JPL |
594913 ꞌAylóꞌchaxnim | 0.457 | 0.5554 | 0.654 | 0.1770 | 15.87 | 151 | 609 | 16.2 | 1500+1100 −600 |
Zwicky Transient Facility | MPC · JPL |
2020 HA10 | 0.692 | 0.8196 | 0.947 | 0.1552 | 49.65 | 271 | 3248 | 18.9 | 590 | Mount Lemmon Survey | MPC · JPL |
2020 OV1 | 0.476 | 0.6376 | 0.800 | 0.2541 | 32.58 | 186 | 1169 | 18.9 | 590 | Zwicky Transient Facility | MPC · JPL |
2021 BS1 | 0.396 | 0.5984 | 0.800 | 0.3377 | 31.73 | 169 | 46 | 18.5 | 710 | Zwicky Transient Facility | MPC · JPL |
2021 LJ4 | 0.416 | 0.6748 | 0.933 | 0.3834 | 9.83 | 202 | 5 | 20.1 | 340 | Scott S. Sheppard | MPC · JPL |
2021 PB2 | 0.610 | 0.7174 | 0.825 | 0.1501 | 24.83 | 222 | 3392 | 18.8 | 620 | Zwicky Transient Facility | MPC · JPL |
2021 PH27 | 0.133 | 0.4617 | 0.790 | 0.7117 | 31.93 | 115 | 1515 | 17.7 | 1,020 | Scott S. Sheppard | MPC · JPL |
2021 VR3 | 0.313 | 0.5339 | 0.755 | 0.4138 | 18.06 | 143 | 1012 | 18.0 | 890 | Zwicky Transient Facility | MPC · JPL |
2022 BJ8 | 0.590 | 0.7852 | 0.981 | 0.2487 | 15.83 | 254 | 102 | 19.6 | 430 | Kitt Peak-Bok | MPC · JPL |
2023 EL | 0.579 | 0.7676 | 0.956 | 0.2453 | 13.63 | 246 | 9 | 18.9 | 580 | Scott S. Sheppard | MPC · JPL |
2023 EY2 | 0.398 | 0.6033 | 0.809 | 0.3978 | 35.55 | 171 | 6 | 19.9 | 370 | Kitt Peak-Bok | MPC · JPL |
2023 WK3 | 0.321 | 0.6436 | 0.966 | 0.5010 | 24.63 | 189 | 3 | 20.5 | 280 | Moonbase South Observatory | MPC · JPL |
- (A) All diameter estimates are based on an assumed albedo of 0.14 (except 163693 Atira, for which the size has been directly measured)
- (B) Binary asteroid
See also
- List of minor planet groups
- List of minor planets
Notes
- ^ Cambridge Conference Correspondence, (2): WHAT'S IN A NAME: APOHELE = APOAPSIS & HELIOS – from Dave Tholen, Cambridge Conference Network (CCNet) DIGEST, 9 July 1998
Benny,
Duncan Steel has already brought up the subject of a class name for objects with orbits interior to the Earth's. To be sure, we've already given that subject some thought. I also wanted a word that begins with the letter "A", but there was some desire to work Hawaiian culture into it. I consulted with a friend of mine that has a master's degree in the Hawaiian language, and she recommended "Apohele", the Hawaiian word for "orbit". I found that an interesting suggestion, because of the similarity to fragments of "apoapsis" and "helios", and these objects would have their apoapsis closer to the Sun than the Earth's orbit. By the way, the pronunciation would be like "ah-poe-hey-lay". Rob Whiteley has suggested "Aliʻi", which refers to the Hawaiian elite, which provides a rich bank of names for discoveries in this class, such as Kuhio, Kalakaua, Kamehameha, Liliuokalani, and so on. Unfortunately, I think the okina (the reverse apostrophe) would be badly treated by most people.
I wasn't planning to bring it up at this stage, but because Duncan has already done so, here's what we've got on the table so far. I'd appreciate some feedback on the suggestions.
--Dave - oscillations in orbital eccentricity and inclination
- ^ The nickname "Vatira" combined "Venus" with "Atira".[15]
References
- ^ a b Baalke, Ron. "Near-Earth Object Groups". Jet Propulsion Laboratory. NASA. Archived from the original on 2 February 2002. Retrieved 11 November 2016.
- ^ a b Chodas, Paul; Khudikyan, Shakeh; Chamberlin, Alan (14 May 2019). "Near-Earth Asteroid Discovery Statistics". Jet Propulsion Laboratory. NASA. Retrieved 25 May 2019.
- Bibcode:1998DPS....30.1604T.
- ^ (Ulukau Hawaiian Electronic Library)
- .
- .
- ^ S2CID 209324310.
- ^ a b c "JPL Small-Body Database Search Engine: Q < 0.983 (AU)". JPL Solar System Dynamics. NASA. Retrieved 30 December 2017.
- ^ "Small-Body Database Query". Solar System Dynamics – Jet Propulsion Laboratory. NASA – California Institute of Technology. Retrieved 2023-02-05.
- ^ "Asteroids with aphelia between 0.983 and 1.017 AU". Retrieved 25 May 2019.
- .
- ^ S2CID 119239031.
- S2CID 160009327.
- ^ S2CID 116216149. Retrieved February 9, 2023.
- ^ hdl:2429/37251.
We have provisionally named objects with 0.307 < Q < 0.718 AU Vatiras, because they are Atiras which are decoupled from Venus. Provisional because it will be abandoned once the first discovered member of this class will be named.
- ^ . Retrieved 1 October 2022.
- ^ "JPL Small-Body Database Browser: 2020 AV2". Jet Propulsion Laboratory. NASA. Archived from the original on 11 January 2020. Retrieved 9 January 2020.
- . Retrieved February 9, 2023.
- . Retrieved 18 January 2024.
- . Retrieved 18 January 2024.
- ^ Masi, Gianluca (9 January 2020). "2020 AV2, the first intervenusian asteroid ever discovered: an image – 08 Jan. 2020". Virtual Telescope Project. Retrieved 9 January 2020.
- S2CID 219687045. Retrieved 8 July 2020.
External links
- List Of Aten Minor Planets, Minor Planet Center