Orion's Sword | |
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Angular separation 42 Ori - Nair Al Saif = 1° |
1st group |
Name | Flamsteed | SAO | Yale | HD | Magn. | Dist. | Type | Temp.°K. |
- | 42 Ori | 132320 | 1892 | 37018 | 4.59 | 540 | B1V | 25.600 |
- | 45 Ori | 132336 | 1901 | 37077 | 5.26 | 281 | F0IV | 7.400 |
2nd group |
The Trapezium is probably the best know multiple star in the sky. It is also one of the most interesting for the small telescope. In many double star catalogs it has become customary to designate the fours stars A, B,C, and D in order of right ascension (right to left in the pict.) rather than in the usual order of brightness. The fainest star, B, is an eclipsing binary with a period of 6.5 days. In 1975, star A was also identified as an eclipsing binary with a period of 65.5 days. In the picture are also visible the 11th magnitude stars E (beside A) and F (close to C). They are a well known observational challenge to amateur astronomers who often use them to judge the quality of the seeing as well as the quality of their telescopes. |
Name | Flamsteed | Star | SAO | Yale | HD | Magn. | Trapezium | Dist. | Type | Temp.°K. |
Trapezium (Theta 1) | 41 Ori | C | 132314 | 1895 | 37022 | 5.13 | 3.7 | 1.470 | O6 | 37.600 |
D | - | 1896 | 37023 | 6.70 | 1.470 | B0V | 28.000 | |||
A | - | 1893 | 37020 | 6.73 | 1.470 | B0V | 28.000 | |||
B | - | 1894 | 37021 | 7.96 | 1.470 | B0V | 28.000 | |||
Theta 2 | 43 Ori | - | 132321 | 1897 | 37041 | 5.08 | - | 2.720 | O9V | 30.400 |
3rd group |
Name | Flamsteed | SAO | Yale | HD | Magn. | Dist. | Type | Temp.°K. |
Nair Al Saif (Iota Ori) | 44 Ori | 132323 | 1899 | 37043 | 2.77 | 1.810 | O9III | 30.400 |
- | - | 132301 | 1887 | 36960 | 4.78 | 650 | B0V | 28.000 |
- | - | 132298 | 1886 | 36959 | 5.67 | 650 | B1V | 25.600 |
astro | carlo g. | art | meteo | italy | sundial |