Sextans

From Free net encyclopedia

For the Ancient Roman coin denomination, see sextans (coin).

For the Sextans Dwarf galaxy, see Sextans (dwarf galaxy).

Sextans (Latin for Sextant) is a minor southern constellation which was introduced in the 17th century by Johannes Hevelius.

1 Notable features
2 Notable deep sky objects
3 Mythology
4 Notable and named stars
5 See also
6 External links

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Notable features

Sextans is not a particularly bright constellation. It has only one star above the fifth magnitude, namely α Sextantis at magnitude 4.49. The constellation contains a few double stars, including γ, 35, and 40 Sextantis. There are few notable variable stars.

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Notable deep sky objects

There are a few galaxies in Sextans. The most notable is NGC 3115 (called the Spindle galaxy), a spiral galaxy of magnitude 9.1 that is seen edge-on. It is believed to be around 20 million light years away. There are a few other galaxies, including NGC 3156, NGC 3165, NGC 3166, and NGC 3169, a group of four galaxies 60 million light years away. NGC 3166 and NGC 3169 are the brightest of the quartet, at tenth magnitude. These two galaxies, which are separated by only around 50,000 light years, are so close to each other that they affect each other's structure. NGC 3156 is of magnitude 12.4, and NGC 3165 is of magnitude 13.9.

Designation	Type	Right ascension (J2000.0)	Declination (J2000.0)	Size	Mag.
NGC 3115	galaxy	10^h 05^m 14.1^s	-07° 43′ 09″	8.3′ × 3.2′	9.1
NGC 3166	galaxy	10^h 13^m 45.6^s	+03° 25′ 31″	5.2′ × 2.7′	10.4
NGC 3169	galaxy	10^h 14^m 14.8^s	+03° 28′ 00″	4.8′ × 3.2′	10.2

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Mythology

Being a modern constellation, Sextans has no mythology associated with it. It was deigned to represent a sextant, an instrument that Hevelius made frequent use of in his observations.

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Notable and named stars

BD	F	Mag.	Star Names and other designations	Right ascension (J2000.0)	Declination (J2000.0)	Ly away	Comments
α	15	4.49	Alpha Sextantis	10^h 07^m 56.3^s	−00° 22' 18"	287
γ	8	5.05	Gamma Sextantis, ADS 7555	09^h 52^m 30.4^s	−08° 06' 18"	262	double star; component magnitudes +5.58, +6.07
β	30	5.09v	Beta Sextantis	10^h 30^m 17.5^s	−00° 38' 13"	345	α² CVn type variable star
δ	29	5.21	Delta Sextantis	10^h 29^m 28.7^s	−02° 44' 21"	300
ε	22	5.24	Epsilon Sextantis	10^h 17^m 37.8^s	−08° 04' 08"	183
	18	5.65	18 Sextantis	10^h 10^m 55.8^s	−08° 25' 06"
	19	5.77	19 Sextantis	10^h 12^m 48.3^s	+04° 36' 53"
	35	5.79	35 Sextantis, ADS 7902	10^h 43^m 20.9^s	+04° 44' 52"		double star; component magnitudes: +5.79 +7.14
	41	5.79	41 Sextantis, ADS 7942	10^h 50^m 18.1^s	−08° 53' 52"
	17	5.91	17 Sextantis	10^h 10^m 07.5^s	−08° 24' 30"
	25	5.97v	SS Sextantis, 25 Sextantis	10^h 23^m 26.5^s	−04° 04' 27"
	6	6.01	6 Sextantis	09^h 51^m 14.0^s	−04° 14' 36"
	7	6.02	7 Sextantis	09^h 52^m 12.2^s	+02° 27' 15"
	14	6.21	14 Sextantis	10^h 06^m 47.4^s	+05° 36' 41"
	4	6.24	4 Sextantis	09^h 50^m 30.1^s	+04° 20' 37"
	33	6.26	33 Sextantis	10^h 41^m 24.2^s	−01° 44' 30"
	36	6.28	36 Sextantis	10^h 45^m 09.4^s	+02° 29' 17"
	26	6.33	26 Sextantis	10^h 26^m 36.9^s	−00° 59' 17"
	37	6.38	37 Sextantis	10^h 46^m 05.7^s	+06° 22' 24"
	13	6.45	13 Sextantis	10^h 04^m 08.4^s	+03° 12' 04"
	27	6.55	27 Sextantis	10^h 26^m 46.9^s	−04° 23' 18"
	34	6.57	34 Sextantis	10^h 42^m 37.5^s	+03° 34' 59"
	40	6.61	40 Sextantis, ADS 7936	10^h 49^m 17.3^s	−04° 01' 27"
	23	6.66v	RS Sextantis, 23 Sextantis	10^h 21^m 02.0^s	+02° 17' 23"
	12	6.70	12 Sextantis	09^h 59^m 43.1^s	+03° 23' 05"
	9	6.72	9 Sextantis	09^h 54^m 06.7^s	+04° 56' 43"
	21	6.97	21 Sextantis	10^h 14^m 08.4^s	−07° 59' 36"
	31	6.98	31 Sextantis	10^h 30^m 31.0^s	+02° 09' 01"
	20	7.37	20 Sextantis	10^h 13^m 44.4^s	−07° 23' 02"
		15.6	LHS 292	10^h 48^m 13^s	−11° 20' 12"	14.81	flare star nearby