Discovery [1] | |
---|---|
Discovered by | C. J. van Houten I. van Houten T. Gehrels |
Discovery site | Palomar Obs. |
Discovery date | 16 October 1977 |
Designations | |
(9826) Ehrenfreund | |
Named after | Pascale Ehrenfreund (Austrian astrophysicist) [2] |
2114 T-3 ·1993 VH2 | |
main-belt · Eos [3] | |
Orbital characteristics [1] | |
Epoch 4 September 2017 (JD 2458000.5) | |
Uncertainty parameter 0 | |
Observation arc | 39.66 yr (14,486 days) |
Aphelion | 3.2560 AU |
Perihelion | 2.7308 AU |
2.9934 AU | |
Eccentricity | 0.0877 |
5.18 yr (1,892 days) | |
295.74° | |
0° 11m 25.08s / day | |
Inclination | 8.9529° |
215.57° | |
112.60° | |
Physical characteristics | |
Dimensions | 6.94 km (calculated) [3] 8.378±0.267 km [4] [5] |
3.7484±0.0013 h [6] | |
0.14 (assumed) [3] 0.191±0.024 [4] [5] | |
S [3] | |
12.8 [4] ·13.096±0.002(R) [6] ·13.1 [1] ·13.38±0.26 [7] ·13.55 [3] | |
9826 Ehrenfreund, provisional designation 2114 T-3, is a stony Eoan asteroid from the outer region of the asteroid belt, approximately 7 kilometers in diameter.
The asteroid was discovered on 16 October 1977, by Dutch astronomer couple Ingrid and Cornelis van Houten at Leiden, on photographic plates taken by Dutch–American astronomer Tom Gehrels at the Palomar Observatory in California, United States. [8] It was later named for Austrian astrophysicist and biochemist Pascale Ehrenfreund. [2]
Ehrenfreund is a member of the Eos family, an orbital group of more than 4,000 asteroids, which are well known for mostly being of stony composition. It orbits the Sun in the outer main-belt at a distance of 2.7–3.3 AU once every 5 years and 2 months (1,892 days). Its orbit has an eccentricity of 0.09 and an inclination of 9° with respect to the ecliptic. [1]
The first used observation was taken at the discovering observatory on 7 October 1977, extending the body's observation arc by just 9 days prior to its official discovery observation. [8]
The survey designation "T-3" stands for the last of three Palomar–Leiden Trojan surveys, named after the fruitful collaboration of the Palomar and Leiden Observatory in the 1960s and 1970s. Gehrels used Palomar's Samuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped the photographic plates to Ingrid and Cornelis van Houten at Leiden Observatory where astrometry was carried out. The trio are credited with the discovery of several thousand minor planets. [9]
Since 221 Eos, the parent of the collisional Eos family, has been characterized as a rare K-type asteroid in the SMASS classification, Ehrenfreund may as well reveal such spectral type.
A rotational lightcurve for this asteroid was obtained from photometric observations taken at the U.S. Palomar Transient Factory in August 2013. It gave a rotation period of 3.7484±0.0013 hours with a brightness variation of 0.37 in magnitude ( U=2 ). [6]
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Ehrenfreund measures 8.4 kilometers in diameter and its surface has an albedo of 0.19, [4] while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.14 – derived from 221 Eos the family's largest member and namesake – and calculates a diameter of 6.9 kilometers with an absolute magnitude of 13.55. [3]
This minor planet was named in honour of Austrian astrophysicist and biochemist, Pascale Ehrenfreund (born 1960), who has analyzed dust particles and circumstellar organic molecules on a number of space missions. [2] Ehrenfreund has been the lead investigator at NASA Astrobiology Institute and was elected CEO of the German Aerospace Center in 2015, the first woman to lead a major research facility in Germany. [10] The approved naming citation was published by the Minor Planet Center on 11 November 2000 ( M.P.C. 41570). [11]
1743 Schmidt, provisional designation 4109 P-L, is a dark background asteroid from the inner regions of the asteroid belt, approximately 19 kilometers in diameter. It was discovered during the Palomar–Leiden survey on 24 September 1960, by astronomers Ingrid and Cornelis van Houten at Leiden, on photographic plates taken by Tom Gehrels at Palomar Observatory in California. The C-type asteroid has a rotation period of 17.5 hours. It was named for the optician Bernhard Schmidt.
2114 Wallenquist, provisional designation 1976 HA, is a Themistian asteroid from the outer region of the asteroid belt, approximately 28 kilometers in diameter. It was discovered by Swedish astronomer Claes-Ingvar Lagerkvist at the Australian Mount Stromlo Observatory near Canberra, on 19 April 1976.
10252 Heidigraf, provisional designation 4164 T-1, is a Koronian asteroid from the outer regions of the asteroid belt, approximately 6 kilometers in diameter. It was discovered during the Palomar–Leiden Trojan survey on 26 March 1971, by Ingrid and Cornelis van Houten at Leiden, and Tom Gehrels at Palomar Observatory in California, United States. The likely elongated S-type asteroid has a brightness variation of 0.56 magnitude. It was named after Heidi Graf, a former Head of the ESTEC Communications Office.
9994 Grotius, provisional designation 4028 P-L, is a stony Rafita asteroid from the middle regions of the asteroid belt, approximately 3.5 kilometers in diameter. It was discovered during the Palomar–Leiden survey in 1960, and named after Dutch jurist Hugo Grotius.
8776 Campestris, provisional designation 2287 T-3, is a stony background asteroid from the central region of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 16 October 1977, by Dutch astronomer couple Ingrid and Cornelis van Houten at Leiden Observatory, and Dutch–American astronomer Tom Gehrels at the Palomar Observatory in California, United States. The asteroid was named for the tawny pipit, a shorebird.
9912 Donizetti, provisional designation 2078 T-3, is a stony Rafita asteroid from the central regions of the asteroid belt, approximately 7 km in diameter. It was discovered during the third Palomar–Leiden Trojan survey in 1977, and named after Italian composer Gaetano Donizetti.
9910 Vogelweide, provisional designation 3181 T-2, is a stony Koronian asteroid and elongated slow rotator from the outer regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered during the second Palomar–Leiden trojan survey in 1973, and named after German medieval poet Walther von der Vogelweide.
6805 Abstracta, provisional designation 4600 P-L, is a carbonaceous Themistian asteroid and slow rotator from the outer region of the asteroid belt, approximately 10 kilometers in diameter.
5101 Akhmerov, provisional designation 1985 UB5, is an Eos asteroid from the outer region of the asteroid belt, about 12 kilometers in diameter. It was discovered on 22 October 1985, by Russian astronomer Lyudmila Zhuravleva at the Crimean Astrophysical Observatory in Nauchnyj, on the Crimean peninsula. It was later named for Ukrainian surgeon Vadim Akhmerov.
10656 Albrecht is a carbonaceous background asteroid from the outer region of the asteroid belt, approximately 10 kilometers in diameter. It was named after German astronomer Carl Theodor Albrecht.
8121 Altdorfer, provisional designation 2572 P-L, is a stony Flora asteroid from the inner regions of the asteroid belt, approximately 2 kilometers in diameter. Discovered during the Palomar–Leiden survey in 1960, the asteroid was later named for Renaissance painter Albrecht Altdorfer.
3936 Elst, provisional designation 2321 T-3, is a stony Vestian asteroid from the inner regions of the asteroid belt, approximately 5 kilometers in diameter. The asteroid was discovered on 16 October 1977, 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. It was named after Belgian astronomer Eric W. Elst.
2054 Gawain, provisional designation 4097 P-L, is a dark and elongated asteroid from the outer regions of the asteroid belt, approximately 19 kilometers in diameter. Discovered during the Palomar–Leiden survey at Palomar Observatory in 1960, the asteroid was later named after Gawain, a knight of King Arthur's Round Table in the Arthurian legend.
2003 Harding, provisional designation 6559 P-L, is a carbonaceous Eoan asteroid from the outer regions of the asteroid belt, approximately 18 kilometers in diameter. It was discovered during the Palomar–Leiden survey on 24 September 1960, by astronomers Ingrid and Cornelis van Houten at Leiden, and Tom Gehrels at Palomar, California. The asteroid was later named after astronomer Karl Ludwig Harding.
1924 Horus, provisional designation 4023 P-L, is a dark asteroid from the inner regions of the asteroid belt, approximately 12 kilometers in diameter. Discovered during the Palomar–Leiden survey in 1960, it was later named after Horus from Egyptian mythology.
6615 Plutarchos, provisional designation 9512 P-L, is a Florian asteroid and suspected binary from the inner regions of the asteroid belt, approximately 3.1 kilometers in diameter. Discovered during the Palomar–Leiden survey in 1960, the asteroid was later named after the Greek philosopher Plutarch. Its minor-planet moon was discovered in 2007.
1979 Sakharov, provisionally designated 2006 P-L, is a stony Vestian asteroid from the inner regions of the asteroid belt, approximately 4.5 kilometers in diameter. It was discovered during the Palomar–Leiden survey in 1960, and named after Russian physicist Andrei Sakharov.
3201 Sijthoff, provisional designation 6560 P-L, is a background or Florian asteroid from the inner regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered during the Palomar–Leiden survey on 24 September 1960, by Ingrid and Cornelis van Houten at Leiden, and Tom Gehrels at Palomar Observatory in California, United States. The assumed S-type asteroid has a rotation period of 4.607 hours. It was named after Dutch publisher and popularizer of astronomy, Albert Georg Sijthoff.
1778 Alfvén, also designated 4506 P-L, is a carbonaceous Themistian asteroid from the outer region of the asteroid belt, approximately 20 kilometers in diameter.
10551 Göteborg, provisional designation 1992 YL2, is a stony Eoan asteroid and slow rotator from the outer region of the asteroid belt, approximately 13 kilometers in diameter. It was discovered on 18 December 1992, by Belgian astronomer Eric Elst at CERGA in Caussols (010), southeastern France. The asteroid was named after the Swedish city of Gothenburg (Göteborg).