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(399307) 1991 RJ2: A NEW NEA BINARY DISCOVERY
Brian D Warner1, Joseph T Pollock2, Daniel E Reichart3
1Center for Solar System Studies - Palmer Divide Station, (CS3-PDS), 446 Sycamore Ave., Eaton, CO 80615 USA.
The Minor Planet Bulletin
|May 28, 2020
Summary
Near-Earth asteroid 1991 RJ2 is a binary system. Its secondary satellite is tidally locked, with a diameter ratio of 0.47, indicating a slightly elongated shape.
Area of Science:
- Astronomy and astrophysics
- Planetary science
Background:
- Binary asteroid systems are crucial for understanding solar system formation.
- Near-Earth asteroids (NEAs) provide insights into the early solar system's composition and evolution.
Purpose of the Study:
- To analyze photometric observations of NEA (399307) 1991 RJ2.
- To determine the orbital characteristics and physical properties of the 1991 RJ2 system.
Main Methods:
- CCD photometric observations were conducted in August-September 2014.
- Lightcurve analysis was used to identify mutual events and determine orbital periods.
Main Results:
- NEA (399307) 1991 RJ2 was confirmed as a binary system.
- The primary rotation period is 3.4907 ± 0.0002 hours.
- The orbital period of the secondary is 15.917 ± 0.001 hours, with a diameter ratio (Ds/Dp) of 0.47 ± 0.02.
Conclusions:
- The secondary satellite is tidally locked to the orbital period.
- The satellite exhibits a slightly elongated shape (a/b ~ 1.07/1.0).
- The findings contribute to the understanding of binary asteroid dynamics and evolution.
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