Apollo near-Earth asteroid
2016 DV1 is a near-Earth asteroid estimated to be roughly 29–65 meters (95–210 feet) in diameter. It is a fast rotating asteroid of the Apollo group which was first observed by the Mount Lemmon Survey on 28 February 2016, just days before it passed Earth at 1 lunar distance (LD) on 3 March 2016. The elongated fast rotator has a rotation period of 303 seconds. It was recovered in February 2021 as it was about to pass Earth on 3 March 2021 at a distance of 0.0053 AU (2.1 LD; 790,000 km; 490,000 mi).[3]
Orbit
2016 DV1 orbits the Sun at a distance of 0.7–3.0 AU once every 2 years and 6 months (913 days; semi-major axis of 1.84 AU). Its orbit has a high eccentricity of 0.63 and an inclination of 3° with respect to the ecliptic.[3] It has an Earth minimum orbital intersection distance of 0.001 AU (0.39 LD; 150,000 km). Due to its eccentric orbit, 2016 DV1 is also a Mars-crosser, crossing the orbit of the Red Planet at 1.66 AU.[3]
2016 discovery
It was first observed by the Mount Lemmon Survey on 28 February 2016,[1] when the asteroid was about 0.04 AU (6,000,000 km; 3,700,000 mi) from Earth and had a solar elongation of 174°. The last optical image was at 3 March 2016 03:08 UT.[2] Bistatic Solar System Radar (GSSR) with DSS-13 and the Green Bank Observatory were used to image the asteroid.[8] It passed closest approach to Earth on 3 March 2016 05:17 UT at a distance of 0.00264 AU (1.03 LD; 395,000 km; 245,000 mi)[3] and was quickly approaching the glare of the Sun thus preventing further optical observations.[9]
2021 approach
It was recovered on 17 February 2021 by Pan-STARRS[2] when the uncertainty in the asteroid's sky position covered about 1.2° of the sky.[10]
By early February 2021 the asteroid was brighter than apparent magnitude 24,[10][c] which still placed it near the limiting magnitude of even the best automated astronomical surveys. It came to opposition (opposite the Sun in the sky) around 26 February 2021 at around magnitude 19.[10] On 3 March 2021 it passed 0.0053 AU (2.1 LD; 790,000 km; 490,000 mi) from Earth.[3] It was not listed on the Sentry Risk Table because the line of variation (LOV) did not pass through where Earth will be.
Physical characteristics
Rotation period
In March 2016, a rotational lightcurve of 2016 DV1 was obtained from photometric observations by American astronomer Brian Warner at the Palmer Divide Station (U81) at the Center for Solar System Studies in California. Lightcurve analysis gave a well-defined rotation period of 0.084148±0.000005 hours (or 302.9 seconds) with a high brightness variation of 0.56±0.04 in magnitude, indicative of an irregular shape (U=3).[7][b] On the following night, European astronomers Siegfried Eggl, William Thuillot, Maria Kudryashova, and Raoul Behrend determined a similar period of 0.08435±0.00005 hours (or 303.7 seconds) and an even higher amplitude of 1.02±0.03 magnitude.(U=3).[11]
Diameter
The diameter can only be estimated. Based on a generic absolute magnitude-to-diameter conversion, 2016 DV1 measures approximately 40 meters (130 feet) in diameter given an absolute magnitude of 24.8 and an assumed albedo of 0.14.[4][5] Since the near-Earth population shows a bimodal distribution with two albedo-peaks at 0.25 and 0.05, 2016 DV1 may measure 29–65 meters (95–210 feet) in diameter,[a] for a corresponding stony and carbonaceous composition, respectively.
