Sextant (constellation)
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Constellation sextant |
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| Latin name | Sextans |
| Latin genitive | Sextantis |
| Abbreviation | sex |
| Right ascension | 09 h 41 m 05 s to 10 h 51 m 30 s |
| declination | −11 ° 39 ′ 44 ″ to + 6 ° 25 ′ 58 ″ |
| surface | 313,515 deg² rank 47 |
| Completely visible | 78.5 ° N to 84.1 ° S |
| Observation time for Central Europe | spring |
| Number of stars brighter than 3 mag | 0 |
| Brightest star (size) | Sextantis (4.49) |
| Meteor streams | |
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Neighboring constellations ( clockwise from north ) |
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| swell | IAU , |
The sextant ( Latin sextans ) is a constellation near the celestial equator .
description
The sextant is an inconspicuous constellation that can hardly be seen in the night sky. Only one of its stars is brighter than the 5th magnitude . The sextant lies between the distinctive lion (Leo) and the elongated water snake (Hydra).
There are several galaxies in the sextant , one of which can already be observed with a smaller telescope .
history
The constellation was introduced in 1690 by the Danzig astronomer Johannes Hevelius . It is supposed to represent the sextant with which he measured the star positions.
Before Hevelius, the monk Anton Maria Schyrleus de Rheita had combined the stars of this heavenly region in 1643 to form the handkerchief of Christ . However, this designation could not prevail.
Celestial objects
Stars
| B. | F. | Names or other designations | m | Lj | Spectral class |
|---|---|---|---|---|---|
| α | 15th | 4.49 | 287 | A0 III | |
| γ | 8th | 5.05 | 262 | A2 V | |
| β | 30th | 5.09 | 345 | B6 V | |
| δ | 29 | 5.21 | 300 | B9.5 V | |
| ε | 22nd | 5.24 m | 183 | F2 III | |
| 18th | 5.65 | ||||
| 19th | 5.77 | ||||
| 35 | 5.79 | ||||
| 41 | 5.79 | ||||
| 17th | 5.91 | ||||
| 25th | SS | 5.97v | |||
| 6th | 6.01 | ||||
| 7th | 6.02 | ||||
| 14th | 6.21 | ||||
| 4th | 6.24 | ||||
| 33 | 6.26 | ||||
| 36 | 6.28 | ||||
| 26th | 6.33 | ||||
| 37 | 6.38 | ||||
| 13 | 6.45 | ||||
| 27 | 6.55 | ||||
| 34 | 6.57 | ||||
| 40 | 6.61 | ||||
| 23 | RS | 6.66v | |||
| 12 | 6.70 | ||||
| 9 | 6.72 | ||||
| 21st | 6.97 | ||||
| 31 | 6.98 | ||||
| 20th | 7.37 |
The brightest star in the sextant is the α sextantis, 287 light years away. It is a bluish-white shining star of the spectral class A0 III with a surface temperature of 15,000 ° C.
Double stars
| system | m | distance |
|---|---|---|
| γ | 5.6 / 6.1 | 0.6 " |
| 35 | 6.1 / 7.2 | 6.8 " |
γ Sextantis is a binary star system 262 light years away. The two components are bluish-white stars of the spectral classes A1 and A4. Due to the small angular distance of only 0.6 arc seconds , the system can only be resolved into single stars in larger telescopes.
The system 35 sextantis is 800 light years away and consists of two orange stars of the spectral classes K3 and K0. The stars can already be observed with a smaller telescope.
Variable stars
| object | m | period | Type |
|---|---|---|---|
| β | α 2 Canis Venaticorum star |
β Sextantis is a variable star of the type α 2 Canis Venaticorum, 345 light years away .
Messier and NGC objects
| Messier (M) | NGC | other | m | Type | Surname |
|---|---|---|---|---|---|
| 3115 | 9.1 | Galaxy | Spindle Galaxy | ||
| 3156 | 12.4 | Galaxy | |||
| 3165 | 13.9 | Galaxy | |||
| 3166 | 10.4 | Galaxy | |||
| 3169 | 10.2 | Galaxy |
NGC 3115 is an edge-facing galaxy 25 million light-years away; i.e., we see them from the side. In the telescope it appears elongated and is reminiscent of a spindle , which is why it is also known as the “spindle galaxy”.
The galaxies NGC 3156 , NGC 3165 , NGC 3166, and NGC 3169 form a group of galaxies 60 million light years away. The galaxies NGC 3166 and NGC 3169 are only about 50,000 light years apart. Due to the effect of gravity , they mutually influence their structures.
Since the group of galaxies is relatively far away and therefore faint, a larger telescope is required for observation.
Other objects
The sextant contains CL J1001 + 0220 as one of the most distant galaxy clusters with a redshift of z = 2.506.
