4337 Arecibo
Discovery Synodic rotation period | 32.972823 h (Gaia DR3)[5]: 16 32.85±0.38 h[6][5] | |
---|---|---|
Pole ecliptic latitude | 60°±3°[5]: 16 | |
Pole ecliptic longitude | 261°±3°[5]: 16 | |
0.077±0.004[7][1] 0.06±0.02[8] | ||
11.9±0.1[7] · 12.45[8] 12.52[1][2] | ||
4337 Arecibo (
History
Discovery
This asteroid was discovered by American astronomer
Naming
The asteroid was named after the Arecibo Observatory in Puerto Rico, home to the world's largest filled-aperature radio telescope in the 20th century. The name was proposed by radar astronomer Steven J. Ostro, in recognition of the observatory's indispensable contributions to the characterization of Solar System bodies including asteroids.[2] The official naming citation was published by the Minor Planet Center on 8 June 1990.[13]: 155
Occultations and satellite discovery
On 19 May 2021, two
Several days after the discovery of Arecibo's satellite, other occultation astronomers were alerted to follow up in another occultation event by Arecibo over North America on 9 June 2021.[9] Richard Nolthenius and Kirk Bender, separated from each other by 8.2 km (5.1 mi) across and 8 km (5.0 mi) along Arecibo's shadow path, successfully observed the 9 June 2021 occultation from central California.[4]: 3 As Arecibo passed in front of a magnitude 12.0 star, they detected the primary two-second-long occultation starting at 10:58 UTC and then the satellite make a secondary occultation three seconds later, confirming the existence of Arecibo's satellite.[9][4]: 4 The satellite discovery and confirmation results from the May and June 2021 occultations were formally published by Central Bureau for Astronomical Telegrams on 20 June 2021.[14] Discoverers Gault and Nosworthy recognize Arecibo's satellite as the first asteroid moon discovered by amateur astronomers, and confirmed using the occultation method.[9][a]
On 30 June 2021, astronomers across the United States prepared for another occultation by Arecibo to further follow up on its satellite, but majority of them experienced technical difficulties and unfavorable weather conditions, resulting in only 5 out of 15 different sites making successful observations. Only 3 of the 5 successful sites reported positive detections (Nolthenius, Bender, and Christopher Kitting of CSU East Bay reported positives) with a single occultation; the other two had misses and did not detect the satellite. It is possible the satellite and main body were a blended image, given the close orbit later determined.[4]: 4
Orbit and classification
Arecibo orbits the Sun in the
Because of its low orbital inclination, Arecibo is visible along the ecliptic at apparent magnitudes 16–18.[2] Arecibo is too faint to be seen with the naked eye, even when at its peak brightness of magnitude 16 at opposition—a telescope of at least 60 cm (24 in) in aperture size is required to see it.[16]
Physical characteristics
The spectral class of Arecibo is unknown, but it can be assumed to be a carbonaceous C-type,[3] similar to most members of the Themis family.[15]: 320 Like most members of the Themis family, Arecibo likely has a highly porous internal structure with a low density below 1.3 g/cm3, as indicated by its mass determined from the satellite's orbital motion.[5]: 17
Diameter and albedo
Based on occultation observations from 9 June 2021, the primary body of the Arecibo system measures 24.4 ± 0.6 km (15.16 ± 0.37 mi) in diameter, assuming that it has a spherical shape.
Rotation
In July 2021, a preliminary rotational
Based on Gaia photometry, Arecibo's north pole points in the direction of
Satellite
Discovery[14] | |
---|---|
Discovered by | D. Gault P. Nosworthy |
Discovery date | 19 May 2021 |
Orbital characteristics[5]: 16 | |
49.9±1.0 km | |
32.972823 h | |
Inclination | 30°±3° wrt ecliptic[b] |
Satellite of | 4337 Arecibo |
Physical characteristics | |
Mean diameter | 13±1.5 km[4]: 4 |
Mean density | <1.3 g/cm3[5]: 17 |
Arecibo hosts a relatively large
Orbit
The observed
On 13 June 2022, a team of European astronomers led by Paolo Tanga, on behalf of the European Space Agency, published a proof-of-concept analysis of the Arecibo system using high-precision astrometry and photometry from the Gaia mission, as part of its third data release.[19][5]: 16 They found that Arecibo exhibits periodic oscillations in brightness and position that are both compatible with a period of 32.972823 hours (1.3738676 d), consistent with earlier ground-based photometry from July 2021 and establishing the satellite's orbital period.[6][5]: 16 They determined a smaller orbital radius of 49.9 ± 1.0 km (31.01 ± 0.62 mi) and an inclination of 30°±3° with respect to the ecliptic, precisely coinciding with the satellite's positions observed in the May and June 2021 occultations.[5]: 16 [b] Given the satellite's close proximity to the primary body and coincidence of brightness and position oscillation periods, the satellite is likely in synchronous orbit with the primary's rotation period.[5]: 16
Physical characteristics
The initial detection of the satellite in the 19 May 2021 occultation provided poor constraints on its size due to close spacing between the observers' sites.[14] The 9 June 2021 occultation proved to be more reliable with wider spacing between observer sites, providing a best-fit satellite diameter of 13 ± 1.5 km (8.08 ± 0.93 mi) for an assumed spherical shape for the satellite.[4]: 4 Given this diameter estimate, this makes the satellite about half the size of the primary body in the Arecibo system.[5]: 16
The satellite is massive enough to induce measurable positional wobbling of the Arecibo primary, although with an unexpectedly low amplitude of up to 2.7 milliarcseconds from Gaia's view, or 8.5% of the maximum observed angular separation between the satellite and primary.[5]: 16 This small positional wobbling of the Arecibo primary implies a very low satellite-to-primary mass ratio relative to the satellite-to-primary diameter ratio, which could either be explained by a highly flattened shape or a very low density for the satellite.[5]: 17 Tanga and collaborators favor the high flattening scenario as it yields more realistic density values and can explain the infrared underestimation of the primary's diameter.[5]: 17 In this case, the occultation-derived satellite diameter would represent its maximum shape extent and its minimum possible density would be 1 g/cm3, which is expected for a highly porous asteroid of the Themis family.[5]: 17
Notes
- ^ 2258 Viipuri may also have a putative satellite that was solely detected in two single-chord occultations from 3 August 2013 and 19 September 2018, but the timespan between these detections is too sparse to determine the satellite's orbital motion.[18]: 40
- ^ ecliptic coordinates, where λ is ecliptic longitude and β is ecliptic latitude.[5]: 16 β is the angular offset from the ecliptic plane and inclination i with respect to the ecliptic is the angular offset from the ecliptic north pole at β = +90°; i with respect to the ecliptic would be the complement of β.[17]Therefore, given β = 60°, i = 90° – 60° = 30° from the ecliptic.
References
- ^ a b c d e f g "4337 Arecibo (1985 GB)" (2021-09-24 last obs.). Jet Propulsion Laboratory. Archived from the original on 7 February 2022. Retrieved 16 June 2022.
- ^ a b c d e f g "(4337) Arecibo = 1933 HE = 1979 FR3 = 1979 HG2 = 1985 GB". Minor Planet Center. Archived from the original on 4 October 2016. Retrieved 16 June 2022.
- ^ a b c d e f "LCDB Data for (4337) Arecibo". Asteroid Lightcurve Database (LCDB). Collaborative Asteroid Lightcurve Link. Archived from the original on 29 June 2022. Retrieved 16 June 2022.
- ^ Bibcode:2022MPBu...49....3G. Archivedfrom the original on 29 June 2022. Retrieved 16 June 2022.
- ^ (PDF) from the original on 13 June 2022. Retrieved 16 June 2022.
- ^ a b c Behrend, Raoul. "Asteroids and comets rotation curves, CdR & Regular variable stars light curves, CdL". Observatoire de Genève. Archived from the original on 3 August 2003. Retrieved 16 June 2022.
- ^ from the original on 16 June 2022. Retrieved 16 June 2022.
- ^ S2CID 119289027. 63.
- ^ a b c d e f g Nosworthy, Peter; Gault, Dave. "Arecibo Moon Discovery". Hazelbrook Observatory. Archived from the original on 28 January 2022. Retrieved 16 June 2022.
- ^ a b "M. P. C. 9671" (PDF). Minor Planet Circulars (9671). Minor Planet Center: 71. 4 May 1985. Archived (PDF) from the original on 10 August 2017. Retrieved 17 June 2022.
- ^ "M. P. C. 10039" (PDF). Minor Planet Circulars (10039). Minor Planet Center: 59. 29 September 1985. Archived (PDF) from the original on 10 August 2017. Retrieved 16 June 2022.
- ^ "M. P. C. 15690" (PDF). Minor Planet Circulars (15690). Minor Planet Center: 90. 11 January 1990. Archived (PDF) from the original on 24 February 2013. Retrieved 16 June 2022.
- ^ "M. P. C. 16445" (PDF). Minor Planet Circulars. Minor Planet Center. 8 June 1990. p. 155. Archived (PDF) from the original on 23 June 2021. Retrieved 16 June 2022.
- ^ a b c d "CBET 4981 : (4337) ARECIBO". Central Bureau Electronic Telegrams (4981). Central Bureau for Astronomical Telegrams. 20 June 2021. Archived from the original on 28 January 2022. Retrieved 16 June 2022.
- ^ S2CID 119280014.
- ^ Houdart, Robert. "Telescope Limiting Magnitude Calculator". Cruxis. Archived from the original on 26 May 2021. Retrieved 17 June 2022.
- ^ "Coordinate transformations". Astronomy and Astrophysics. European Southern Observatory. January 1998. Archived from the original on 17 June 2021. Retrieved 17 June 2022.
- ^ a b c Nugent, Richard (January 2022). "The International Occultation Timing Association's 39th Annual Meeting, 2021 July 17-18 via Zoom Online" (PDF). Journal for Occultation Astronomy. 12 (1): 38–40. Archived (PDF) from the original on 3 April 2022. Retrieved 16 June 2022.
- ^ Roegiers, Tineke; Tanga, Paolo; Galluccio, Laurent (13 June 2022). "Is it a Solar System object?". European Space Agency. Archived from the original on 14 June 2022. Retrieved 16 June 2022.
External links
- Barry, Tony. "4337 Arecibo - a possible binary asteroid?". Western Sydney Amateur Astronomy Group. 20 May 2021.
- Johnston, Wm. Robert. "(4337) Arecibo" Asteroids with Satellites Database. Johnston's Archive. 30 April 2022.
- 4337 Arecibo at AstDyS-2, Asteroids—Dynamic Site
- 4337 Arecibo at the JPL Small-Body Database