Comet du Toit - Hartley (79P / du Toit – Hartley) is a short-period comet from the Jupiter family, which in 1976 split into two fragments. It was discovered on April 9, 1945 by the American astronomer Daniel du Tua at the Boyden Observatory , after which for several years it was not observed and was considered lost until in February 1982 it was rediscovered by the English astronomer Malcolm Hartley at the Siding Spring Observatory . It has a rather short period of revolution around the Sun - just a little over 5 years.
- The orbit of comet du Tua - Hartley and its position in the solar system
| 79P / du Tua - Hartley | |
|---|---|
| Opening | |
| Discoverer | Daniel du Tua ; Malcolm Hartley |
| opening date | April 9, 1945 |
| Alternative notation | 1945 G1; 1982 C1-A |
| Characteristics of the orbit [1] | |
| Age of September 23, 2013 JD 2456558.5 | |
| Eccentricity | 0.6185135 |
| Semimajor axis ( a ) | 440.694 million km (2,9458586 AU ) |
| Perihelion ( q ) | 168.119 million km (1,1238053 A.E.) |
| Aphelion ( Q ) | 713.269 million km (4.7679119 AU) |
| Circulation Period ( P ) | 1846.785 days (5.056 g. ) |
| Orbital inclination | 3,14562 ° |
| Last perihelion | August 23, 2013 |
| Next perihelion | September 13, 2018 [2] [3] |
| physical characteristics | |
| Dimensions | 2.8 km |
At the time of detection, the comet was a diffuse object of 10 m magnitude. Three days later, on April 12, the Dutch astronomer H. Van Gent managed to photograph the comet, thereby confirming the fact of its discovery. About 37 years later, on the night of February 5–6, 1982, the British astronomer Malcolm Hartley discovered two comets with a magnitude of 14 m and 17 m of stellar magnitude using the 1.2-meter telescope of the Schmidt system. Both comets had small tails. KS Russell was the first to note the surprising similarities in the movement of the two comets and suggested that they may have a common origin.
Observation History
The appearance of 1945. The comet was observed by astronomers of the Boyden Observatory until May 31 and astronomers of the Harvard Observatory until June 4. The first orbit model was calculated by J. Jackson based on the position of the comet on April 12, May 1 and May 17. Based on these calculations, the date of passage of the perihelion was April 16, 1945. Later, LE Cunningham calculated the elliptical orbit of the comet using data collected over the entire period of its observation (58 days). Since du Tua already discovered one comet in 1944, this one got the name Comet du Tua 2 .
Subsequently, for almost four decades, despite repeated attempts to amend the existing orbit model, due to perturbations from Jupiter and Saturn , it was not possible to detect a comet. This continued until 1982, until February 19, S. Nakano noticed that the orbit of the recently discovered double comet by Malcolm Hartley coincided strongly with the orbit of comet du Tua 2, lost in 1945. Brian Marsden re-calculated the orbit, according to which the date of passage of the perihelion was April 26, 1982. Marsden added that according to calculations in December 1963, the comet experienced a rapprochement with Jupiter to a distance of 0.34 a. e. (51 million km), which could affect the integrity of the comet. However, according to Z. Sekanina, the final separation of the fragments occurred only a few years later at the end of 1976. He also noted that the most massive component is noticeably fainter and suggested that the brightness of the comet may continue to decline. The last time a comet was observed was Alan Gilmore and Pamela Kilmartin at Mount John Observatory .
The next time the comet was observed on March 29, 2003, by astronomers at the Los Molinos Observatory (Uruguay) using a 46 cm reflector and a CCD camera, the brightness of the comet was 17.5 m .
Notes
- ↑ Elements and Ephemeris for 79P / du Toit-Hartley . Minor Planet Center. Date of treatment May 26, 2016.
- ↑ Seiichi Yoshida. 79P / du Toit-Hartley . Seiichi Yoshida's Comet Catalog (July 3, 2010). Date of treatment February 18, 2012.
- ↑ Syuichi Nakano . 79P / du Toit-Hartley (NK 2411) . OAA Computing and Minor Planet Sections (February 4, 2012). Date of treatment February 18, 2012.
Links
- NASA JPL Small Solar System Bodies (79P )
- Solar System Small Body MPC Database (79P )
- 79P at Kronk's Cometography
- 79P at Kazuo Kinoshita's Comets
| Short period comets with numbers | ||
|---|---|---|
| ◄ 77P / Longmore • 78P / Gehrels • 79P / du Tua - Hartley • 80P / Peters - Hartley • 81P / Wilda ► | ||