Discovery [1] | |
---|---|
Discovered by | LINEAR |
Discovery site | Lincoln Lab's ETS |
Discovery date | 29 September 1998 |
Designations | |
(85713) 1998 SS49 | |
1998 SS49 | |
Apollo · NEO · PHA [1] [2] | |
Orbital characteristics [1] | |
Epoch 4 September 2017 (JD 2458000.5) | |
Uncertainty parameter 0 | |
Observation arc | 18.05 yr (6,593 days) |
Aphelion | 3.1535 AU |
Perihelion | 0.6940 AU |
1.9237 AU | |
Eccentricity | 0.6393 |
2.67 yr (975 days) | |
359.74° | |
0° 22m 9.84s / day | |
Inclination | 10.764° |
41.493° | |
102.47° | |
Earth MOID | 0.0023 AU ·0.9 LD |
Physical characteristics | |
Dimensions | 2.00±0.06 km [3] 2.25 km (calculated) [4] 3.03±1.49 km [5] 3.484±0.789 km [6] [7] |
5.370±0.005 h [8] [lower-alpha 1] 5.398±0.001 h [9] 5.66±0.01 h [10] [lower-alpha 2] | |
0.076±0.039 [6] [7] 0.08±0.12 [5] 0.20 (assumed) [4] 0.237±0.018 [3] | |
S (assumed) [4] | |
15.6 [1] [4] ·15.70 [3] [7] ·15.80±0.29 [11] ·16.01 [5] | |
(85713) 1998 SS49 (provisional designation 1998 SS49) is an asteroid on an eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 3 kilometers (1.9 miles) in diameter. The asteroid was discovered on 29 September 1998, by astronomers of the LINEAR program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States. [2] It is one of the largest potentially hazardous asteroids and has a notably low Earth-MOID of less than the distance to the Moon. [12]
1998 SS49 is a member of the dynamical Apollo group, [1] [2] which are Earth-crossing asteroids. Apollo asteroids are the largest subgroup of near-Earth objects.
It orbits the Sun at a distance of 0.7–3.2 AU once every 2 years and 8 months (975 days; semi-major axis of 1.92 AU). Its orbit has a high eccentricity of 0.64 and an inclination of 11° with respect to the ecliptic. [1] The body's observation arc begins with its official discovery observation at Socorro in September 1998. [2]
At about absolute magnitude 15.6, 1998 SS49 is one of the brightest and presumably largest known potentially hazardous asteroid (see PHA-list). [12] It has a very low Earth minimum orbital intersection distance of 0.0023 AU (340 thousand km ; 0.90 LD ). [1] On 26 November 1902, this asteroid made its closest near-Earth encounter since 1900 at a nominal distance of 0.0659 AU (9.86 million km ; 25.6 LD ). The next notable close approach was on 21 November 2022, passing at a nominal distance of 0.141 AU (21,100,000 km; 13,100,000 mi). [1]
1998 SS49 is also a Venus- and Mars-crosser, as it crosses the orbit of Venus and the Red Planet at c. 0.72 and 1.66 AU, respectively.
1998 SS49 is an assumed, stony S-type asteroid. [4]
In 2014, two rotational lightcurves of 1998 SS49 were obtained from photometric observations by American astronomer Brian Warner at the CS3–Palmer Divide Station in California ( U82 ). Lightcurve analysis gave a rotation period of 5.370 and 5.66 hours and a brightness variation of 0.18 and 0.06 magnitude, respectively ( U=2/2 ), one of which gave an alternative period solution of 2.686±0.002 hours. [8] [10] [lower-alpha 1] [lower-alpha 2] In April 2016, the EURONEAR lightcurve survey measured a period of 5.398 hours with an amplitude of 0.12 magnitude ( U=2 ).
Surveys contrast: of the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer. These measure the object as between 2 and 3.484 kilometers lengthways (in diameter) and to have an albedo (optical wavelength reflectivity) between 0.076 and 0.237. [3] [5] [6] [7] The Collaborative Asteroid Lightcurve Link assumes a stony typical albedo of 0.20 to calculate the diameter as 2.25 kilometers and an absolute magnitude of 15.6. [4]
This minor planet was numbered by the Minor Planet Center on 30 August 2004. [13] As of 2018, it has not been named. [2]
4183 Cuno, provisional designation 1959 LM, is an eccentric, rare-type asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, and measures approximately 4 kilometers in diameter.
3728 IRAS, provisional designation 1983 QF, is a stony asteroid from the middle region of the asteroid belt, approximately 20 kilometers in diameter. On 23 August 1983, it was discovered by and later named after IRAS, a spaceborne all-sky infrared survey satellite.
1799 Koussevitzky is an asteroid of the Eos family from the outer regions of the asteroid belt, approximately 18 kilometers in diameter. It was discovered on 25 July 1950, by astronomers at Indiana University during the Indiana Asteroid Program at Goethe Link Observatory in Indiana, United States. The K-type asteroid has a rotation period of 6.3 hours. It was named for Russian conductor Serge Koussevitzky.
2023 Asaph, provisional designation 1952 SA, is a dark asteroid from the outer regions of the asteroid belt, approximately 21 kilometers in diameter. It was discovered on 16 September 1952, by astronomers of the Indiana Asteroid Program at Goethe Link Observatory in Indiana, United States.
(12538) 1998 OH is a stony asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 1.8 kilometers in diameter. It was discovered on 19 July 1998, by astronomers of the Near-Earth Asteroid Tracking program at the Haleakala Observatory in Hawaii, United States. In 2019, the asteroid came within about 73 lunar distances of Earth.
4401 Aditi is an eccentric, stony asteroid, classified as a near-Earth object and Amor asteroid, approximately 1.8 kilometers in diameter. It was discovered on 14 October 1985 by American astronomer Carolyn Shoemaker at Palomar Observatory in California, and later named after the Hindu goddess Aditi.
1568 Aisleen, provisional designation 1946 QB, is a stony Phocaea asteroid from the inner regions of the asteroid belt, approximately 12.5 kilometers in diameter. It was discovered on 21 August 1946, by South African astronomer Ernest Johnson at Johannesburg Observatory in South Africa. It is named for the discoverer's wife, Aisleen Johnson.
3037 Alku, provisional designation 1944 BA, is a carbonaceous asteroid from the central region of the asteroid belt, approximately 20 kilometers in diameter. It was discovered on 17 January 1944, by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland.
1589 Fanatica, provisional designation 1950 RK, is a stony, Vestian asteroid from the inner regions of the asteroid belt, approximately 11 kilometers in diameter. It was discovered on 13 September 1950, by Argentine astronomer Miguel Itzigsohn at La Plata Astronomical Observatory in La Plata, Argentina. It was named after Eva Perón.
3800 Karayusuf, provisional designation 1984 AB, is a Mars-crossing asteroid and suspected binary system from inside the asteroid belt, approximately 2.5 kilometers in diameter. It was discovered on 4 January 1984, by American astronomer Eleanor Helin at the Palomar Observatory in California. The S/L-type asteroid has a short rotation period of 2.2 hours. It was named after Syrian physician Alford Karayusuf, a friend of the discoverer.
4547 Massachusetts is a dark background asteroid from the central regions of the asteroid belt, approximately 24 kilometers in diameter. It was discovered on 16 May 1990, by Japanese astronomers Kin Endate and Kazuro Watanabe at the JCPM Sapporo Station on the island of Hokkaido, Japan. The asteroid was named for the U.S. state of Massachusetts.
3066 McFadden, provisional designation 1984 EO, is a stony background asteroid from the central regions of the asteroid belt, approximately 15 kilometers in diameter. It was discovered on 1 March 1984, by American astronomer Edward Bowell at the Anderson Mesa Station near Tucson, Arizona. It was named for American planetary scientist Lucy-Ann McFadden. The assumed S-type asteroid has a rotation period of 13.8 hours.
1297 Quadea, provisional designation 1934 AD, is an Eoan asteroid from the outer regions of the asteroid belt, approximately 23 kilometers in diameter. It was discovered on 7 January 1934, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in Germany. The asteroid was named for the parents-in-law of the discoverer's brother.
For other uses, see Steel (disambiguation).
1266 Tone is a dark background asteroid from the outer regions of the asteroid belt, approximately 80 kilometers in diameter. Discovered by astronomer Okuro Oikawa at the Tokyo Observatory in 1927, it was assigned the provisional designation 1927 BD. The asteroid was later named after the Tone River, one of Japan's largest rivers.
20936 Nemrut Dagi is a stony Hungaria asteroid and Mars-grazer from the innermost regions of the asteroid belt, approximately 3.5 kilometers in diameter. It was discovered on 13 May 1971, by Dutch astronomer couple Ingrid and Cornelis van Houten at Leiden, on photographic plates taken by Dutch–American astronomer Tom Gehrels at Palomar Observatory in California, United States. The asteroid has a rotation period of 3.28 hours, a likely spheroidal shape, and a high albedo typically seen among the enstatite-rich E-type asteroids. In 2012, it was named after the a dormant volcano Nemrut in Turkey.
(90075) 2002 VU94 (provisional designation 2002 VU94) is an asteroid on an eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 2.5 kilometers in diameter. It was discovered on 13 November 2002, by astronomers of the Near-Earth Asteroid Tracking program at Palomar Observatory in California, United States. It is one of the largest potentially hazardous asteroids known.
(159857) 2004 LJ1, provisional designation 2004 LJ1, is an asteroid on an eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 3 kilometers in diameter. The asteroid was discovered on 10 June 2004, by astronomers of the LINEAR program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States. It is one of the largest potentially hazardous asteroids known to exist.
(21601) 1998 XO89 (provisional designation 1998 XO89) is a Jupiter trojan from the Greek camp, approximately 55 kilometers (34 miles) in diameter. It was discovered on 15 December 1998, by astronomers with the Lincoln Near-Earth Asteroid Research at the Lincoln Lab's ETS near Socorro, New Mexico. The dark Jovian asteroid has a rotation period of 12.7 hours and belongs to the 80 largest Jupiter trojans. It has not been named since its numbering in February 2001.
(163348) 2002 NN4 (prov. designation:2002 NN4) is a dark, sub-kilometer near-Earth object and potentially hazardous asteroid of the Aten group that flew by Earth on 6 June 2020. The highly elongated X-type asteroid has a rotation period of 14.5 hours and measures approximately 0.7 kilometers (0.4 miles) in diameter. It was discovered by LINEAR at the Lincoln Laboratory's Experimental Test Site in New Mexico on 9 July 2002.