astro.wikisort.org - Asteroid

4257 Ubasti, provisional designation 1987 QA, is a stony asteroid, classified as near-Earth object of the Apollo group and as Mars-crosser, approximately 1.5 kilometers in diameter. It was discovered by American astronomer Jean Mueller at the Palomar Observatory in California on 23 August 1987.[3] The asteroid was named for Bastet – also known as Baast, Ubaste or Ubasti – the Egyptian goddess of cats.[2]

4257 Ubasti

Discovery [1]
Discovered by	J. E. Mueller
Discovery site	Palomar Obs.
Discovery date	23 August 1987
Designations
MPC designation	(4257) Ubasti
Named after	Bastet [2] (Egyptian goddess of cats)
Alternative designations	1987 QA
Minor planet category	NEO · Apollo [1][3] Mars-crosser
Orbital characteristics [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	29.02 yr (10,600 days)
Aphelion	2.4183 AU
Perihelion	0.8759 AU
Semi-major axis	1.6471 AU
Eccentricity	0.4682
Orbital period (sidereal)	2.11 yr (772 days)
Mean anomaly	28.670°
Mean motion	0° 27m 58.32s / day
Inclination	40.716°
Longitude of ascending node	169.22°
Argument of perihelion	278.92°
Earth MOID	0.1714 AU · 66.8 LD
Physical characteristics
Dimensions	1.30±0.09 km[4] 1.96 km (calculated)[5]
Geometric albedo	0.20 (assumed)[5] 0.376±0.053[4]
Spectral type	S [5]
Absolute magnitude (H)	15.9[1][5] · 16.20[4]

Orbit and classification

Ubasti orbits the Sun at a distance of 0.9–2.4 AU once every 2 years and 1 month (772 days). Its orbit has an eccentricity of 0.47 and an inclination of 41° with respect to the ecliptic.[1] Due to its high eccentricity, Ubasti is also a Mars-crossing asteroid. The body's observation arc begins with its official discovery observation, as no precoveries were taken and no prior identification had been made.[3]

Close approaches

As a near-Earth object, Ubasti has a low Earth minimum orbital intersection distance of 0.1714 AU (25,600,000 km), which corresponds to 66.8 lunar distances (LD). This distance, however, is too large to make it a potentially hazardous asteroid (0.05 AU; less than 20 LD).[1]

Physical characteristics

Ubasti is an assumed stony S-type asteroid.[5]

Rotation period

As of 2017, no rotational lightcurve of Ubasti has been obtained and its rotation period remains unknown.[5] However, the Lowell Observatory Near-Earth Asteroid Photometric Survey has measured the body's brightness variation caused by its rotation, which gave a maximum of 0.36 magnitude. This indicates that the body has a somewhat non-spherical shape.[6]

Diameter and albedo

According to the survey carried out by the Japanese Akari satellite, Ubasti measures 1.30 kilometers in diameter and its surface has an albedo of 0.376,[4] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 1.96 kilometers based on an absolute magnitude of 15.9.[5]

Naming

This minor planet was named after Egyptian goddesses Bastet, who was originally the goddess of warfare, equated with the lioness war goddess, but later transformed into a major protector deity represented as a cat.[2] The official naming citation was published by the Minor Planet Center on 21 November 1991 (M.P.C. 19336).[7] The discoverer dedicated this asteroid to her beloved companion, Pepper Cat (1974–1991).[2]

References

External links

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• 4257 Ubasti at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemeris · Obs prediction · Orbital info · MOID · Proper elements · Obs info · Close · Physical info · NEOCC
• 4257 Ubasti at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical Properties · Summary
• 4257 Ubasti at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

На других языках

---

[de] (4257) Ubasti

(4257) Ubasti ist ein erdnaher Asteroid des Apollo-Typs, der am 23. August 1987 von der US-amerikanischen Astronomin Jean Mueller am Palomar-Observatorium (Sternwarten-Code 675) in Kalifornien entdeckt wurde.

---

- [en] 4257 Ubasti

---

[ru] (4257) Убасти

(4257) Убасти (лат. Ubasti) — околоземный астероид из группы аполлонов, который характеризуется крайне вытянутой орбитой, из-за чего, в процессе своего движения вокруг Солнца, он пересекает не только орбиту Земли, но и Марса. Астероид был открыт 23 августа 1987 года американским астрономом Джин Мюллер в Паломарской обсерватории и назван в честь Баст, древнеегипетской богини радости, веселья и женской красоты[2].

---

---