| Discovery[1] | |
|---|---|
| Discovered by | T. Kobayashi |
| Discovery site | Ōizumi Obs. |
| Discovery date | 3 January 1997 |
| Designations | |
| (7505) Furusho | |
Named after | Reiko Furusho[1] (Japanese astronomer) |
| 1997 AM2 · 1940 WC 1944 OG · 1950 BA1 1970 WG · 1991 NS | |
| Mars-crosser[1][2][3] | |
| Orbital characteristics[2] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 77.37yr (28,258 d) |
| Aphelion | 3.6410AU |
| Perihelion | 1.6305 AU |
| 2.6357 AU | |
| Eccentricity | 0.3814 |
| 4.28 yr (1,563 d) | |
| 132.46° | |
| 0° 13m 49.08s / day | |
| Inclination | 6.3771° |
| 86.492° | |
| 288.02° | |
| Earth MOID | 0.645 AU (251LD) |
| Mars MOID | 0.2486 AU |
| Physical characteristics | |
| 9.07±0.7 km[4] 10.04±1.00 km[5] | |
| 4.139±0.001 h[6][a] | |
| 0.211[5] 0.3732[4] | |
| S(assumed)[3] | |
| 11.9[4] 12.30[1][2][5] | |
7505 Furusho, provisional designation1997 AM2, is a stonyasteroid and sizableMars-crosser on an eccentric orbit from theasteroid belt, approximately 10 kilometers (6.2 miles) in diameter. It was discovered on 3 January 1997, by Japanese astronomerTakao Kobayashi at theŌizumi Observatory in the Kantō region of Japan.[1] The assumedS-type asteroid is likely elongated in shape and has arotation period of 4.1 hours. It was named for Japanese astronomerReiko Furusho.[1]
Furusho is a member of theMars-crossing asteroids, a dynamically unstablegroup between themain belt and thenear-Earth populations, crossing the orbit ofMars at 1.66 AU.[1] It orbits the Sun at a distance of 1.6–3.6 AU once every 4 years and 3 months (1,563 days;semi-major axis of 2.64 AU). Its orbit has a higheccentricity of 0.38 and aninclination of 6° with respect to theecliptic.[2] The body'sobservation arc begins with its first observation as1940 WC at the CrimeanSimeiz Observatory in November 1940, or more than 56 years prior to its official discovery observation byTakao Kobayashi at Ōizumi in January 1997.[1]
Thisminor planet was named after Japanese astronomer Reiko Furusho (born 1970). Her research includescometary physics, in particular the measurement ofpolarized light, caused by scattering oncomet dust. Furusho also works in the education and popularization of astronomy.[1] The officialnaming citation was published by theMinor Planet Center on 1 May 2003 (M.P.C. 48388).[7]
Furusho is an assumedS-type asteroid.[3]
In November 2017, a rotationallightcurve ofFurusho was obtained fromphotometric observations by Daniel Klinglesmith at Etscorn Observatory (719) in Socorro, New Mexico. Lightcurve analysis gave a well-definedrotation period of4.139±0.001 hours with a high brightness variation of 0.63magnitude (U=3).[6]
The result agrees with previous period determinations by Hungarian astronomers atKonkoly Observatory in autumn 2001 (U=3),[8] and with observations by astronomers at thePalomar Transient Factory in California in May 2011 (U=3).[9]Robert Stephens at Santana Observatory (646) andBrian Warner at the Palmer Divide Station (U82) also determined an identical period in November 2001 and December 2013, respectively (U=3/3).[10][11] All observations showed a classically shaped bimodal lightcurve with a high brightness amplitude between 0.52 and 0.75 magnitude, which is indicative of an elongated, non-spherical shape.[a]
According to the survey carried out by the Infrared Astronomical SatelliteIRAS,Furusho measures 9.07 kilometers in diameter and its surface has analbedo of 0.37.[4] In 2017, a study dedicated to Mars-crossing asteroids by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer determined a diameter of 10.04 kilometers with an albedo of 0.21.[5] TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.29 and a diameter of 8.9 kilometers based on anabsolute magnitude of 12.20.[3]
With a diameter of 10 kilometers,Furusho is a typical "sizable" Mars-crosser (5–15 km) of which two dozens or so are known. These include3581 Alvarez (13.7 km)1065 Amundsenia (9.8 km),1139 Atami (9.4 km),3737 Beckman (14.4 km),1474 Beira (15.5 km),5682 Beresford (7.3 km),7369 Gavrilin (5.5 km),1011 Laodamia (7.4 km),6170 Levasseur (5.7 km),1727 Mette (5.4 km),1131 Porzia (7.1 km),985 Rosina (8.2 km),1235 Schorria (5.6 km),1310 Villigera (15.2 km), and1468 Zomba (7 km), which are themselves smaller than the largest members of this dynamical group, namely,132 Aethra,323 Brucia (former Mars-crosser),1508 Kemi,2204 Lyyli and512 Taurinensis, all larger than 20 kilometers.
