Astéroïde binaire

Un système astéroïdal est ...

Généralités

Astéroïdes binaires

Le terme d'astéroide binaire désigne un système de deux astéroïdes tournant l'un autour de l'autre et de tailles équivalentes. On peut citer comme exemple le système 90 Antiope. Un exemple d'astéroïde binaire est 90 Antiope, dont les deux composants de taille égale orbitent l'un autour de l'autre.

Astéroïdes ternaires

Voir aussi

... Catégorie:Satellite d'astéroïde catégorie:astéroïde

(90) Antiope

Antiope (90) Antiope est un astéroïde. Il a été découvert par Robert Luther le 1 octobre 1866 et porte le nom d'Antiope, personnage de la mythologie grecque. Des mesures récentes ont permis de constater que (90) Antiope est en fait un astéroïde binaire.

Situation

(90) Antiope est situé dans la ceinture d'astéroïdes et fait partie de la famille de Thémis.

Système binaire

Le 10 août 2000, des observations menées par le télescope Keck de l'observatoire du Mauna Kea ont montré que (90) Antiope est en fait un astéroïde double, constitué de deux corps séparés par 170 km qui tourne autour d'un centre de gravité commun . Des observations complémentaires ont indiqué que les deux corps mesurent chacun environ 80 km de diamètre et tournent autour du centre de gravité du système en à peu près 16,5 heures. Ces paramètres connus, la masse et la densité de chacun d'eux ont été déterminées. Leur faible densité (0,6 ± 0,2 g/cm³) suggère qu'ils sont très poreux (au moins 60%). Ils sont de type C, sombres et carbonés.

Voir aussi

Liens internes

- Lune astéroïdale

Liens externes

- [http://www.psi.edu/pds/archive/lc.html Courbe lumineuse de plusieurs astéroïdes, dont (90) Antiope]

Bibliographie

W. J. Merline, L. M. Close, C. Dumas, J. C. Shelton, F. Menard, C. R. Chapman, D. C. Slater, Discovery of Companions to Asteroids 762 Pulcova and 90 Antiope by Direct Imaging, American Astronomical Society, DPS meeting n°32

Maritza Correia

Maritza Correia a.k.a "Ritz" (born December 23, 1981 in San Juan, Puerto Rico) is the first black Puerto Rican in the U.S. Olympic Swimming Team and the first Hispanic-American to set an American swimming record. American Maritza's parents, Vincent and Anne, come from Guayama and moved to San Juan, where Maritza was born and raised. In 1987, when Maritza was seven years old, she was diagnosed with severe scoliosis. Her doctor recommended that Maritza take swimming classes and use swimming as a treatment for her condition. That's how she got started in swimming. In 1989, her family moved and settled in Tampa, Florida. Maritza attended Tampa Bay Technical High School and joined the school's swimnig team. In 1999, she became the U.S. National Champion in the 50m freestlye in the 18 and under category. She was also a four time Florida State Champion in the 100m freestyle. Maritza was a member of the 1997 USA National Junior Team that competed in Sweden and of the 1999 USA Short Cause World Championship Team which competed in Hong Kong. In 2000, Maritza joined the Lady Bulldogs Swimming Team. She aided the team when they won their title in the 400m freestyle relay. She earned a share of the SEC Commissioner's Trophy for high point honors. Maritza hoped to participate at the 2000 Summer Olympics in Sydney. She went to the pre-Olympic try-outs, but she missed making the team. This was one of the lowest points of her life; she suffered depression, became dissapointed at the sport of swimming, and needed psychological help. However, a 2000 Team USA member who remains very close friends with her, along with a psychologist, helped her come out of her depression, and re-emerge as a top swimmer. In 2001, Maritza won a gold medal in the 800m freestyle and two bronze medals in the medley and 400m freestyle relay as a member of the U.S. Team at the 2001 World Championship celebrated in Japan. In 2002, Maritza became the national champion in both the 50y and 100y freestyle and was a member of two winning relay teams at the NCAA Championships celebrated in Austin, Texas. She set the NCAA, American and U.S. Open records with a time of 21.69 in the 50y freestyle, surpassing Amy Van Dyken's mark of 21.77 set in 1994. She earned seven All-American certificates and she was awarded the Commissioner's Cup as the high point scorer in the SEC Championships. In 2003, Maritza earned a gold medal swimming on prelim 400m free relay at the World Championships. In 2004, Maritza won a gold medal swimming prelims at the 400m free relay at the Short Cause World Championships and earned a silver medal swimming prelims of the 400m free relay at the 2004 Olympic Games celebrated in Athens, Greece. Maritza attended the University of Georgia as a pre-medicine major and graduated in 2003, with a degree in "Exercise and Sports Science". Some of Maritza's Highlights:
- 2000 NCAA Champion, 200m free, 400m free, 400m MR
- 2001 NCAA Champion 800y Free Relay
- 2002 NCAA Champion 50y free, 100y free, 200y free, 400y free
- All-American 2000-02
- American, NCAA, U.S. Open Record Holder 50y freestyle 21.69 in 2002
- American, NCAA, U.S. Open Record Holder 200y freestyle relay 1:28.74 in 2002
- American, NCAA, U.S. Open Record Holder 400y freestyle relay 3:13.71 in 2002 Correia, Maritza Correia, Maritza Correia, Maritza Correia, Maritza

امتیاز دارسی
قرارداد دارسی یا امتیازنامه دارسی قراردادی است که ویلیام ناکس دارسی در سال ۱۹۰۱ با دولت ایران امضا کرد تا به اکتشاف و استخراج نفت در ایران بپردازد. از طرف ایران مدلهای پنهان مارکوف هستند. برای حل این مسیله با استفاده از زبان‌های آلتائی هستند. زیر شاخه شرقی زبانهای آلتایی شامل زبانهای منچوری و مغولی است. این گروه زبان‌ها

Astéroïde binaire

Généralités

Astéroïdes binaires

Astéroïdes ternaires

Voir aussi

(90) Antiope

Situation

Système binaire

Voir aussi

Liens internes

Liens externes

Bibliographie

Maritza Correia

See also