3267 Glo

3267 Glo, provisional designation 1981 AA, is an eccentric Phocaean asteroid and sizable Mars-crosser from the inner regions of the asteroid belt, approximately 6.4 kilometers (4.0 miles) in diameter. It was discovered on 3 January 1981, by American astronomer Edward Bowell at Lowell's Anderson Mesa Station in Flagstaff, Arizona.^[1] It was later named after American astronomer Eleanor Helin.^[2]

3267 Glo

Discovery[1]
Discovered by	E. Bowell
Discovery site	Anderson Mesa Stn.
Discovery date	3 January 1981
Designations
MPC designation	(3267) Glo
Named after	Eleanor F. Helin (American astronomer)[2]
Alternative designations	1981 AA
Minor planet category	Mars-crosser[1][3] Phocaea[4][5]
Orbital characteristics[3]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc	36.49 yr (13,329 d)
Aphelion	3.0178 AU
Perihelion	1.6424 AU
Semi-major axis	2.3301 AU
Eccentricity	0.2951
Orbital period (sidereal)	3.56 yr (1,299 d)
Mean anomaly	196.67°
Mean motion	0° 16m 37.56s / day
Inclination	24.021°
Longitude of ascending node	110.47°
Argument of perihelion	307.73°
Physical characteristics
Mean diameter	6.45±1.44 km[6] 7.58±0.76 km[7] 13.56±1.1 km[8] 13.59 km (derived)[4]
Synodic rotation period	6.8782±0.0011 h[4][a]
Geometric albedo	0.0607±0.011[8] 0.0725 (derived)[4] 0.233±0.047[7] 0.26±0.12[6]
Spectral type	LS[9] · S (derived)[4]
Absolute magnitude (H)	12.8[3][4][7] · 12.86±0.14[9] 13.19[6]

Orbit and classification

Glo is an eccentric member of the Phocaea family (701),^[5] that orbits the Sun in the inner asteroid belt at a distance of 1.6–3.0 AU once every 3 years and 7 months (1,299 days; semi-major axis of 2.33 AU). Its orbit has an eccentricity of 0.30 and an inclination of 24° with respect to the ecliptic.^[3]

The body's observation arc begins with its official discovery observation at Anderson Mesa in January 1981.^[1]

Physical characteristics

The asteroid has been characterized as an L- and S-type asteroid by Pan-STARRS large-scale survey.^[9]

Spectral type

PanSTARRS' photometric survey, has characterized Glo as a LS-type asteroid, a transitional spectral type between the common S-type and rather rare L-type asteroids,^[9] which have very different albedos, from as low as 0.039 to as high as 0.383.^[10]

Rotation period

A rotational lightcurve of Glo was obtained from photometric observations by Czech astronomer Petr Pravec at Ondřejov Observatory in January 2006. Lightcurve analysis gave a well-defined rotation period of 6.8782 hours with a brightness variation of 0.33 magnitude (U=3).^[4]

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Glo measures 6.45 and 13.56 kilometers in diameter and its surface has an albedo of 0.061 and 0.26, respectively.^[6][8] The Collaborative Asteroid Lightcurve Link agrees with IRAS and derives a similar albedo of 0.0725 and a diameter of 13.59 kilometers with an absolute magnitude of 12.8.^[4][a]

Naming

This minor planet was named in honor of Eleanor "Glo" Helin (1932–2009), who was a planetary scientist at JPL and a prolific discoverer of minor planets.^[2] The official naming citation was published by the Minor Planet Center on 13 February 1987 (M.P.C. 11641).^[11]

Notes

1. Lightcurve plot of 3267 Glo giving a rotation period of 6.8782 hours with an amplitude of 0.0329 magnitude, taken from unpublished data of the Ondrejov Asteroid Photometry Project. Summary figures at the LCDB.