![]() Shape model of Ishihara from its
lightcurve | |
Discovery [1] | |
---|---|
Discovered by |
K. Endate K. Watanabe |
Discovery site | Kitami Observatory |
Discovery date | 16 April 1993 |
Designations | |
(9971) Ishihara | |
Named after | Takahiro Ishihara (Japanese astronomer) [2] |
1993 HS · 1991 YC2 1996 EU1 | |
main-belt [1] [3] · Flora [4] | |
Orbital characteristics [3] | |
Epoch 4 September 2017 ( JD 2458000.5) | |
Uncertainty parameter 0 | |
Observation arc | 24.91 yr (9,097 days) |
Aphelion | 2.4465 AU |
Perihelion | 1.9164 AU |
2.1814 AU | |
Eccentricity | 0.1215 |
3.22 yr (1,177 days) | |
158.69 ° | |
0° 18m 21.24s / day | |
Inclination | 2.7482° |
20.550° | |
246.01° | |
Physical characteristics | |
Dimensions | 4.986±0.053
km
[5] 5.012±0.069 km [6] |
6.715±0.0036
h
[7] 6.71574±0.00001 h [8] | |
Pole
ecliptic latitude | (42.0°, 76.0°) (λ1/β1) [8] |
0.2328±0.0281
[6] 0.235±0.027 [5] | |
S (assumed) [4] | |
13.7 [6] · 13.9 [3] · 13.852±0.006 (R) [7] · 14.3 [4] | |
9971 Ishihara ( prov. designation: 1993 HS) is a stony Flora asteroid from the inner regions of the asteroid belt, approximately 5 kilometers (3.1 miles) in diameter. It was discovered by Japanese amateur astronomers Kin Endate and Kazuro Watanabe at Kitami Observatory on 16 April 1993, [1] and named after Takahiro Ishihara, president of the astronomical society at Hiroshima. [2]
Ishihara is a member of the Flora family, one of the largest families of stony asteroids in the asteroid belt. It orbits the Sun in the inner main-belt at a distance of 1.9–2.4 AU once every 3 years and 3 months (1,177 days). Its orbit has an eccentricity of 0.12 and an inclination of 3 ° with respect to the ecliptic. [3] It was first identified as 1991 YC2 at Karl Schwarzschild Observatory in 1991, extending the body's observation arc by approximately 2 years prior to its official discovery at Kitami. [1]
This minor planet was named after Takahiro Ishihara (born 1961), an observer of comets, communicator of astronomy, and former president of the astronomical society at Hiroshima (1987–1997). [2] The official naming citation was published by the Minor Planet Center on 6 January 2003 ( M.P.C. 47298). [9]
In January 2012, a rotational lightcurve of Ishihara was obtained from photometric observations by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of 6.715±0.0036 hours with a brightness amplitude of 1.06 in magnitude, which indicates that the body has a non-spheroidal shape ( U=2). [7]
A 2016-published lightcurve, using modeled photometric data from the Lowell Photometric Database (LPD), gave a concurring period of 6.71574 hours ( U=n.a.), as well as a spin axis of (42.0°, 76.0°) in ecliptic coordinates (λ, β). [8]
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Ishihara measures 4.986 and 5.012 kilometers in diameter and its surface has an albedo of 0.235 and 0.2328, respectively. [5] [6] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, a S-type asteroid and the family's largest member and namesake – and calculates a diameter of 3.74 kilometers with an absolute magnitude of 14.3. [4]
![]() Shape model of Ishihara from its
lightcurve | |
Discovery [1] | |
---|---|
Discovered by |
K. Endate K. Watanabe |
Discovery site | Kitami Observatory |
Discovery date | 16 April 1993 |
Designations | |
(9971) Ishihara | |
Named after | Takahiro Ishihara (Japanese astronomer) [2] |
1993 HS · 1991 YC2 1996 EU1 | |
main-belt [1] [3] · Flora [4] | |
Orbital characteristics [3] | |
Epoch 4 September 2017 ( JD 2458000.5) | |
Uncertainty parameter 0 | |
Observation arc | 24.91 yr (9,097 days) |
Aphelion | 2.4465 AU |
Perihelion | 1.9164 AU |
2.1814 AU | |
Eccentricity | 0.1215 |
3.22 yr (1,177 days) | |
158.69 ° | |
0° 18m 21.24s / day | |
Inclination | 2.7482° |
20.550° | |
246.01° | |
Physical characteristics | |
Dimensions | 4.986±0.053
km
[5] 5.012±0.069 km [6] |
6.715±0.0036
h
[7] 6.71574±0.00001 h [8] | |
Pole
ecliptic latitude | (42.0°, 76.0°) (λ1/β1) [8] |
0.2328±0.0281
[6] 0.235±0.027 [5] | |
S (assumed) [4] | |
13.7 [6] · 13.9 [3] · 13.852±0.006 (R) [7] · 14.3 [4] | |
9971 Ishihara ( prov. designation: 1993 HS) is a stony Flora asteroid from the inner regions of the asteroid belt, approximately 5 kilometers (3.1 miles) in diameter. It was discovered by Japanese amateur astronomers Kin Endate and Kazuro Watanabe at Kitami Observatory on 16 April 1993, [1] and named after Takahiro Ishihara, president of the astronomical society at Hiroshima. [2]
Ishihara is a member of the Flora family, one of the largest families of stony asteroids in the asteroid belt. It orbits the Sun in the inner main-belt at a distance of 1.9–2.4 AU once every 3 years and 3 months (1,177 days). Its orbit has an eccentricity of 0.12 and an inclination of 3 ° with respect to the ecliptic. [3] It was first identified as 1991 YC2 at Karl Schwarzschild Observatory in 1991, extending the body's observation arc by approximately 2 years prior to its official discovery at Kitami. [1]
This minor planet was named after Takahiro Ishihara (born 1961), an observer of comets, communicator of astronomy, and former president of the astronomical society at Hiroshima (1987–1997). [2] The official naming citation was published by the Minor Planet Center on 6 January 2003 ( M.P.C. 47298). [9]
In January 2012, a rotational lightcurve of Ishihara was obtained from photometric observations by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of 6.715±0.0036 hours with a brightness amplitude of 1.06 in magnitude, which indicates that the body has a non-spheroidal shape ( U=2). [7]
A 2016-published lightcurve, using modeled photometric data from the Lowell Photometric Database (LPD), gave a concurring period of 6.71574 hours ( U=n.a.), as well as a spin axis of (42.0°, 76.0°) in ecliptic coordinates (λ, β). [8]
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Ishihara measures 4.986 and 5.012 kilometers in diameter and its surface has an albedo of 0.235 and 0.2328, respectively. [5] [6] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, a S-type asteroid and the family's largest member and namesake – and calculates a diameter of 3.74 kilometers with an absolute magnitude of 14.3. [4]