Discovery [1] | |
---|---|
Discovered by | E. F. Helin |
Discovery site | Palomar Obs. |
Discovery date | 27 October 1989 |
Designations | |
(5477) Holmes | |
Named after |
Robert Holmes
[1] (American astronomer) |
1989 UH2 | |
main-belt · (
inner)
[2] Hungaria [1] [3] [4] | |
Orbital characteristics [2] | |
Epoch 23 March 2018 ( JD 2458200.5) | |
Uncertainty parameter 0 | |
Observation arc | 27.60 yr (10,082 d) |
Aphelion | 2.0613 AU |
Perihelion | 1.7732 AU |
1.9172 AU | |
Eccentricity | 0.0751 |
2.65 yr (970 d) | |
295.23 ° | |
0° 22m 16.68s / day | |
Inclination | 22.552° |
49.112° | |
290.30° | |
Known satellites | 1 ( D: 1.09 km P: 24.4 h) [3] [5] [6] |
Physical characteristics | |
2.95±0.13
km (derived)
[5] 3.147±0.137 km [7] [8] 3.21 km (taken) [3] 3.215 km [9] | |
2.9932±0.0002
h
[10]
[a] 2.9940±0.0002 h [11] 2.99401±0.00007 h [12] 2.99408±0.00007 h [13] 2.9943±0.0002 h [6] | |
0.2849
[9] 0.310±0.038 [7] [8] | |
E (assumed) [3] | |
13.99±0.03 (R)
[12] 14.0 [2] 14.26±0.54 [14] 14.4 [8] [13] 14.445 [3] [9] | |
5477 Holmes, provisional designation 1989 UH2, is a Hungaria asteroid and binary system from the innermost regions of the asteroid belt, approximately 3 kilometers (2 miles) in diameter. It was discovered on 27 October 1989, by American astronomer Eleanor Helin at the Palomar Observatory in California. [1] The presumed E-type asteroid is likely spherical in shape and has a short rotation period of 2.99 hours. [3] It was named for American amateur astronomer Robert Holmes. [1] The discovery of its 1-kilometer-sized minor-planet moon was announced in November 2005. [5] [6]
Holmes is a core member of the Hungaria family ( 003), [4] a large family of bright asteroids that forms the innermost dense concentration of asteroids in the Solar System, as the Mars-crosser and near-Earth populations are much more sparse. The family is part of the larger dynamical group with the same name. [1] [3] It orbits the Sun in the innermost asteroid belt at a distance of 1.8–2.1 AU once every 2 years and 8 months (970 days; semi-major axis of 1.92 AU). Its orbit has an eccentricity of 0.08 and an inclination of 23 ° with respect to the ecliptic. [2] The body's observation arc begins with its official discovery observation at Palomar in October 1989. [1]
Holmes is an assumed E-type asteroid, [3] which agrees with the overall spectral type for members of the Hungaria family. [15]: 23
Since 2005, several rotational lightcurves of Holmes have been obtained from photometric observations by Brian Warner and Petr Pravec in collaboration with other astronomers. [6] [10] [11] [12] [13] [a] Analysis of the best-rated lightcurve gave a well-defined rotation period of 2.9940 hours with a consolidated brightness amplitude between 0.10 and 0.12 magnitude, which indicates that the body has a nearly spherical shape ( U=3). [3] [11] The asteroid's short period is near that of a fast rotator.
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Holmes measures 3.147 kilometers in diameter and its surface has an albedo of 0.31, [7] [8] while the Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE-data, that is, an albedo of 0.2849 and a diameter of 3.21 kilometers based on an absolute magnitude of 14.445. [3] [9] Johnston's Archive derives a diameter of 2.95 and 3.15 kilometers for the primary only and for the combined system, respectively. [5]
The photometric observations obtained by Brian Warner and collaborators during 2–12 November 2005, [13] revealed that Holmes is a synchronous binary asteroid with a minor-planet moon orbiting it every 24.4 hours at an estimated average distance of 6.7 km. The discovery was announced immediately on 15 November 2005. [6] The mutual occultation events indicated the presence of a satellite 37% the size of its primary, which translates into an estimated diameter of 1.09–1.19 kilometers depending on the underlying size estimate of the primary. [3] [5]
This minor planet was named after American amateur astronomer Robert E. Holmes Jr (born 1956), who directs the Astronomical Research Observatory ( H21) in Westfield, Illinois. [1] The official naming citation was suggested by Sergio Foglia and published by the Minor Planet Center on 18 February 2011 ( M.P.C. 73983). [16]
Discovery [1] | |
---|---|
Discovered by | E. F. Helin |
Discovery site | Palomar Obs. |
Discovery date | 27 October 1989 |
Designations | |
(5477) Holmes | |
Named after |
Robert Holmes
[1] (American astronomer) |
1989 UH2 | |
main-belt · (
inner)
[2] Hungaria [1] [3] [4] | |
Orbital characteristics [2] | |
Epoch 23 March 2018 ( JD 2458200.5) | |
Uncertainty parameter 0 | |
Observation arc | 27.60 yr (10,082 d) |
Aphelion | 2.0613 AU |
Perihelion | 1.7732 AU |
1.9172 AU | |
Eccentricity | 0.0751 |
2.65 yr (970 d) | |
295.23 ° | |
0° 22m 16.68s / day | |
Inclination | 22.552° |
49.112° | |
290.30° | |
Known satellites | 1 ( D: 1.09 km P: 24.4 h) [3] [5] [6] |
Physical characteristics | |
2.95±0.13
km (derived)
[5] 3.147±0.137 km [7] [8] 3.21 km (taken) [3] 3.215 km [9] | |
2.9932±0.0002
h
[10]
[a] 2.9940±0.0002 h [11] 2.99401±0.00007 h [12] 2.99408±0.00007 h [13] 2.9943±0.0002 h [6] | |
0.2849
[9] 0.310±0.038 [7] [8] | |
E (assumed) [3] | |
13.99±0.03 (R)
[12] 14.0 [2] 14.26±0.54 [14] 14.4 [8] [13] 14.445 [3] [9] | |
5477 Holmes, provisional designation 1989 UH2, is a Hungaria asteroid and binary system from the innermost regions of the asteroid belt, approximately 3 kilometers (2 miles) in diameter. It was discovered on 27 October 1989, by American astronomer Eleanor Helin at the Palomar Observatory in California. [1] The presumed E-type asteroid is likely spherical in shape and has a short rotation period of 2.99 hours. [3] It was named for American amateur astronomer Robert Holmes. [1] The discovery of its 1-kilometer-sized minor-planet moon was announced in November 2005. [5] [6]
Holmes is a core member of the Hungaria family ( 003), [4] a large family of bright asteroids that forms the innermost dense concentration of asteroids in the Solar System, as the Mars-crosser and near-Earth populations are much more sparse. The family is part of the larger dynamical group with the same name. [1] [3] It orbits the Sun in the innermost asteroid belt at a distance of 1.8–2.1 AU once every 2 years and 8 months (970 days; semi-major axis of 1.92 AU). Its orbit has an eccentricity of 0.08 and an inclination of 23 ° with respect to the ecliptic. [2] The body's observation arc begins with its official discovery observation at Palomar in October 1989. [1]
Holmes is an assumed E-type asteroid, [3] which agrees with the overall spectral type for members of the Hungaria family. [15]: 23
Since 2005, several rotational lightcurves of Holmes have been obtained from photometric observations by Brian Warner and Petr Pravec in collaboration with other astronomers. [6] [10] [11] [12] [13] [a] Analysis of the best-rated lightcurve gave a well-defined rotation period of 2.9940 hours with a consolidated brightness amplitude between 0.10 and 0.12 magnitude, which indicates that the body has a nearly spherical shape ( U=3). [3] [11] The asteroid's short period is near that of a fast rotator.
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Holmes measures 3.147 kilometers in diameter and its surface has an albedo of 0.31, [7] [8] while the Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE-data, that is, an albedo of 0.2849 and a diameter of 3.21 kilometers based on an absolute magnitude of 14.445. [3] [9] Johnston's Archive derives a diameter of 2.95 and 3.15 kilometers for the primary only and for the combined system, respectively. [5]
The photometric observations obtained by Brian Warner and collaborators during 2–12 November 2005, [13] revealed that Holmes is a synchronous binary asteroid with a minor-planet moon orbiting it every 24.4 hours at an estimated average distance of 6.7 km. The discovery was announced immediately on 15 November 2005. [6] The mutual occultation events indicated the presence of a satellite 37% the size of its primary, which translates into an estimated diameter of 1.09–1.19 kilometers depending on the underlying size estimate of the primary. [3] [5]
This minor planet was named after American amateur astronomer Robert E. Holmes Jr (born 1956), who directs the Astronomical Research Observatory ( H21) in Westfield, Illinois. [1] The official naming citation was suggested by Sergio Foglia and published by the Minor Planet Center on 18 February 2011 ( M.P.C. 73983). [16]