Hydrus (Pronounciation:Hide-rus, Abbrev:Hyi, Latin:Hydri) is a constellation, one of 88 constellations that the night sky is divided into. The sky is not divided up equally between the constellations. Hydrus takes up 243.035 sq. degrees of the night sky which equates to 0.59% of the night sky. The constellation gets its name as it name means The Water Snake . It was not one of the original constellations that had been devised by Ptolemy, instead it was created by Pieter Dirkszoon Keyser and Frederick de Houtman years later.
Hydrus is not a member of the Zodiac group of twelve constellations that appear when the Sun sets. Hydrus is a southern hemispheric constellation which means it can't be seen easily or at all from the northern hemisphere.
The number of stars that have been catalogued as part of the Hipparcos Star Catalogue from Hydrus is 659. The number of stars that are of magnitude 6.0 or lower in the constellation is 20. The number of stars in the constellation that make up the outline is 7.
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 nearest star to Earth is Beta Hydri which is roughly about 24.33 Light Years from the Earth. The nearest star to the Earth with an exoplanet is GJ 3021 which is about 57.07 Light Years. The furthest star that can be located in the constellation is HIP 120027 which is located about 108721 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 dimmest star that can be seen in Hydrus with the naked eye is Kappa Hydri. 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
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.
There is no Greek Legend behind this constellation. It was created by Pieter Dirkszoon Keyser and Frederick de Houtman to fill in the voids in the astronomical charts.
There are 4 Meteor Showers that occur during the year within this constellation based on information gathered from Adam Mickiewicz University (Poland). The ones listed as the ones I've been able to find a date range for. For others if you have the time, you can visit the AMU site, obtains the SL value then use IMO tables to calculate the date. A lot of the Meteor Showers are weak and you need to do a lot of stargazing to spot them.
|Name||Activity||Peak Activity||Closest Star|
|Alpha Hydrids||15-30 Jan||20/21 Jan||Head of Hydrus|
|Sigma Hydrids||Dec 03 - Dec 15||Dec 12||Minchir|
|Is a Zodiac Sign||No|
|Brightest Star||Beta Hydri|
|Area||243.035 sq. deg.|
|Percentage of Night Sky||0.59%|
|Site Exoplanet Count||11|
|Meteor Shower Count||4|
|Nearest Star||Beta Hydri|
|Nearest Star with Exoplanet(s)||GJ 3021|
|Dimmest Star||Kappa Hydri|
|Furthest Star||HIP 120027|
|Bright Star Count||20|
|Hipparcos Star Count||659|
|Main Star Count||7|
|Messier Deep Space Object Count||0|
|*Non-Messier Deep Space Object Count||0|
|Bordering / Neighbouring / Surrounding Constellations||Eridanus|
*Note: The number of Non-Messier Deep Space Object Count relates to how many are covered on this site not how many there are.
The map was generated using Night Vision, an awesome free application by Brian Simpson.
|Star||Distance (Lt. Yrs.)||Exoplanet Count||Declination||Right Ascension|
|HD 10180||127.26||9||-60d 30` 41.6||01h 37m 53.59|
|HD 20003||142.87||2||-72d 19` 18.7||03h 07m 37.78|
As there's so many stars in the cosmos, not all the stars are listed here. The site has lots of stars not listed so if your star isn't listed and you know the Henry Draper or Hipparcos ID, type https://www.universeguide.com/star/ then followed by the HIPNNNNNN or HDNNNN where NNNNN is the number part of the name. The stars that I do list have either a traditional name, a bayer or other classification name.
|Star||Distance (Lt. Yrs.)||Declination||Right Ascension|
|Beta Hydri||24.33||-77d 15` 18.1||00h 25m 39.20|
|BN Hydri||270.23||-78d 59` 21.9||03h 07m 31.90|
|CN Hydri||195.89||-71d 14` 09.4||02h 45m 36.86|
|CT Hydri||467.28||-71d 39` 29.7||03h 45m 23.70|
|Delta Hydri||139.68||-68d 39` 33.9||02h 21m 45.02|
|Epsilon Hydri||151.85||-68d 16` 01.0||02h 39m 35.22|
|Eta Hydri||218.75||-67d 38` 50.9||01h 54m 56.01|
|Eta1 Hydri||709.05||-67d 56` 40.2||01h 52m 34.74|
|Gamma Hydri||214.02||-74d 14` 21.3||03h 47m 14.23|
|GJ 3021||57.07||-79d 51` 03.7||00h 16m 11.24|
|Head of Hydrus||71.79||-61d 34` 11.7||01h 58m 45.87|
|Iota Hydri||96.90||-77d 23` 19.0||03h 15m 57.36|
|Kappa Hydri||317.28||-73d 38` 45.0||02h 22m 52.47|
|Lambda Hydri||211.79||-74d 55` 24.1||00h 48m 35.12|
|Mu Hydri||283.87||-79d 06` 33.3||02h 31m 40.12|
|Nu Hydri||339.40||-75d 04` 00.8||02h 50m 28.54|
|Pi1 Hydri||776.58||-67d 50` 29.6||02h 14m 14.50|
|Pi2 Hydri||488.27||-67d 44` 46.8||02h 15m 28.56|
|Sigma Hydri||132.48||-78d 20` 55.2||01h 55m 50.25|
|Tau1 Hydri||393.92||-79d 08` 53.7||01h 41m 21.29|
|Tau2 Hydri||201.71||-80d 10` 34.2||01h 47m 46.69|
|Theta Hydri||514.45||-71d 54` 09.0||03h 02m 15.40|
|Zeta Hydri||284.36||-67d 37` 00.2||02h 45m 32.53|
|K||Light Orange Star 3,700 - 5,200k||205|
|F||Yellow-White 6,000 - 7,500k||162|
|G||Yellow 5,200 - 6,000k||147|
|A||White 7,500 - 10,000k||61|
|M||Red Dwarf Star <3,700k||36|
|B||Blue-White 10,500 - 30,000k||11|
|sd||sd Type SubDwarf Star||1|
|C||C-Type Carbon Star||2|
|S||S-Type Carbon Star||1|