Octans (Pronounciation:Oct-ans, Abbrev:Oct, Latin:Octantis) is a constellation, one of 88 constellations that the night sky is divided into. The sky is not divided up equally between the constellations. Octans takes up 291.045 sq. degrees of the night sky which equates to 0.71% of the night sky. Octans is the 50th largest in terms of size in the night sky.
The constellation name means The Octant . It was not one of the original constellations that had been devised by Ptolemy, instead it was created by Abbé Nicolas Louis de Lacaille years later.
There are 4 stars that make up the main constellation. The hipparcos satellite scanned and detailed 794 stars. There are 35 stars that can be seen with the naked eye in the constellation on a very clear night sky.
Octans is not a member of the Zodiac group of twelve constellations that appear when the Sun sets. Octans is a southern hemispheric constellation which means it can't be seen easily or at all from the northern hemisphere.
There are no deep space objects that were identified by Charles Messier in this constellation. There are no non-Messier deep space objects in this constellation that are covered at present on this site.
The image at the top right of this page was generated using Night Vision, a free to use and download application by Brian Simspon.
You can't just go to one location and arrive at the constellation because the constellation is made up of stars at different locations and different distances. The nearest main star in the constellation is at a distance of 69.15 light years and the furthest main star is a distance of 298.96 light years. The average distance to the main stars is 183.63 light years.
The caveat of these stars are that they are catalogued on this site. If you know of a star that is nearer or further then do let me know in the comments and I'll add it to the site. The stars mentioned are from the Hipparcos catalogue or have been added because of their special status.
The nearest star to Earth is HIP 113229 which is roughly about 28.1 Light Years from the Earth. The nearest star to the Earth with an exoplanet is HD 142022 which is about 111.97 Light Years.
The furthest star that is located in the constellation is Z Octantis and it is 326163.3 light years away from the Sun. The furthest figure is derived from either the 1997 or 2007 Hipparcos star catalogue parallax figure and it has been known to produce distances that are wrong.
The brightest star in Octans is Nu Octantis and is located about 153.85 light years from the Sun. The star has a apparent magnitude of 3.73 but an absolute magnitude of 2.10 when the star is viewed from a distance of 10 Parsecs or 32.6 Light Years. The star is only recognised as being Nu Octantis rather than having Alpha status.
The dimmest star that can be seen in Octans with the naked eye is Mu1 Octantis. The dim star has an apparent magnitude of 5.99. The dimmest star that a person is able to see with their naked eye is 6.0 magnitude based on the table in the reference. Ref: University of Michigan.
Octans is the southern most constellation and covers the south pole area when you look directly up. Unlike Polaris which is directly overhead in the North Pole, there is not an equivalent. The star closest to the South Pole in terms of overhead has the name Polaris Australis.
This is not visible in the Northern Hemisphere due to its location at the bottom of the Earth so to speak.
As the constellation is the southern most constellation, it can be seen throughout the whole year in the south. The equivalent in the north would be Ursa Minor constellation which geostationary. This statement is based on viewing the night sky from Sydney, Australia. It can be seen all through the night soon after dark. It can be seen in a southernly direction.
There is no Greek Legend behind this constellation. It was created by Abbé Nicolas Louis de Lacaille to fill in the voids in the astronomical charts. It contains the southern most stars and the Polaris Australis. Whilst there is not a visible star that can claim the prize, Sigma Octantis is the closest to that position.
There are 1 Meteor Showers that occur during the year within this constellation based on information gathered from Adam Mickiewicz University (Poland). The list below are major ones and which I have a date period for.
The Meteor Shower is known as the Octantids.
The following list contains the stars that make up the constellation. For a larger list of stars in the entire constellation area, please visit the For a list of named stars, that is stars that don't start HD or HIP, please visit Octans Star List page.
|Name||Bayer||Distance (Lt.Yr.)||Right Ascension||Declination||Spectral Type||Colour|
|Beta Octantis||Beta Octantis||149.27||22h 46m 03.72||-81d 22` 53.8||A9IV/V||White|
|Delta Octantis||Delta Octantis||298.96||14h 26m 55.74||-83d 40` 04.3||K2III||Orange|
|Theta Octantis||Theta Octantis||217.15||00h 01m 35.85||-77d 03` 55.1||K2III||Orange|
|Nu Octantis||Nu Octantis||69.15||21h 41m 28.47||-77d 23` 22.1||K0III||Orange|
|Is a Zodiac Sign||No|
|Brightest Star||Nu Octantis|
|Area||291.045 sq. deg.|
|Percentage of Night Sky||0.71%|
|Site Exoplanet Count||4|
|Meteor Shower Count||1|
|Nearest Star||HIP 113229|
|Nearest Star with Exoplanet(s)||HD 142022|
|Brightest Star||Nu Octantis|
|Dimmest Star||Mu1 Octantis|
|Furthest Star||Z Octantis|
|Bright Star Count||35|
|Hipparcos Star Count||794|
|Main Star Count||4|
|Messier Deep Space Object Count||0|
|Bordering / Neighbouring / Surrounding Constellations||Indus|
*Note: The number of Non-Messier Deep Space Object Count relates to how many are covered on this site not how many there are.
|NGC 2573||Barred Spiral Galaxy||-89 20 04.266828176||01 41 38m 0117607013|
|NGC 6438||Lenticular Galaxy||-85 24 07.281096296||18 22 17m 4368742515|
|NGC 7098||Galaxy||-75 06 40.83||21 44 16m 077|
|NGC 7637||Spiral Galaxy||-81 54 41.699970835||23 26 27m 6141013890|
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