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 brightest star in Hydrus is Beta Hydri. There are 11 Extrasolar Planets (Exoplanets) in this constellation that are detailed on this site. There is a dedicated page for exoplanets in Hydrus. For a list of named stars, that is stars that don't start HD or HIP, please visit Hydrus Star List Page.
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 108721.1 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.
Hydra the constellation associated with this meteor Shower is the biggest constellation in the sky. It represents in one legend the monster that Hercules slayed. Even though the constellation is big, the meteor shower on the other hand is very faint and not spectacular. Given the faintness and there not being many meteors in the shower, it could be assumed that the source of the material for this is a long-period comet and that what we hit is the last remaining remnants of its tail that has not yet burnt up.
|Max Activity Date||12 Dec|
|Activity Period||Dec 03 - Dec 15|
|Zenith Hourly Rate||3|
|Max Activity Date||20 Jan|
|Activity Period||15-30 Jan|