HYDRA west part (April schedule and May schedule)
HYDRA east part (May schedule)

    Hydra constellation is spring constellation. It covers large area of the sky, in fact it is the biggest constellation of all 88 constellations. It is also very long - when Hydra's head is low on the west sky ready to set behind the horizon, Hydra's tail is on the south sky. That has the result that different parts of the constellation are best visible at different times of the night or different months of the year.
     The west part of Hydra is in best position for evening observing in April when it is on the southern sky.
     In February it is rising on the southeastern sky, in March it is higher on the southeastern sky, in April is in best position for evening observing and is on the southern sky and in May is low on the southwestern sky ready to set.
     We will observe it in April when it is in best position for evening observing relatively high on the southern sky and in May when it is low on the southwestern sky.
     The east part of Hydra is in best position for evening observing in May when it is low on the south sky.
     In April it is rising and is very low on the southeastern sky and in May it is in best position for evening observing when is low on the southern sky. 
     We will observe it in May when it is in best position for evening observing and is low on the southern sky. 

Double and multiple stars

     N Hydrae - It is located in the eastern part of the constellation. It consists of two components with visual magnitudes 5.8 and 5.9. It has catalogue number HD 100286. In some star atlases it is marked as 17 Crt ( 17 Crateris). They are separated about 9 arc seconds on the sky. Both stars are similar main sequence twins, a bit larger and hotter than our Sun. They are about 90 light years away from the Earth.
     Epsilon Hydrae - It is located in the western part of the constellation. It consists of two components with visual magnitudes 3.5 and 6.7. Their orbital period is about 1,000 years. They are separated about 3 arc seconds on the sky. The distance to epsilon Hydrae from the Earth is about 150 light years.
     The first component with visual magnitude 3.5 is also binary star, but the separation is only 0.2 arc seconds and their period is about 15 years. One of the stars is giant star and the other is main sequence star.
     The second component with visual magnitude 6.7 is spectroscopic binary system too with orbital period of only 10 days.

Deep sky objects
(will be observed only from dark location outside of the city)

     M 48 - It is an open cluster of stars. It is located in the western part of the constellation. Its visual magnitude on the sky is 5.5 and is about 1,500 light years away from the Earth. It is about 300 million years old. 
     NGC 3242 - It is a planetary nebula. It is located in the western part of the constellation. Its visual magnitude is 8.6 and it is about 1,500 light years away from the Earth. Some call it "Ghost of Jupiter" because in a telescope looks like planet Jupiter. The central star is white dwarf with magnitude 11.0 and the true diameter of the nebula in the space is about 2 light years.
     M 68 - It is globular cluster of stars. It is located in the eastern part of the constellation. Its visual magnitude is 9.7 and it is about 35,000 light years away from the Earth. Its true diameter in the space (from one end to the other end) is about 100 light years. It is about 11 billion years old. Its mass (the mass of all stars of the cluster) is about 200,000 solar (Sun) masses (one solar mass is the mass of our Sun)(Sol is Latin name for the Sun so astronomers often use the term solar, for example solar mass or solar diameter etc).
     M 83 - It is a galaxy. It is located in the eastern part of the constellation. It is face-on spiral galaxy. Face-on means that we see it exactly from above or from bellow - so its shape is roughly circular and we can see its spiral arms clearly. Spiral means that the galaxy has spiral arms. It size (from one end to the other end) is about 40,000 light years (our galaxy the Milky Way size is about 100,000 light years and it is also spiral galaxy). Its visual magnitude is 7.5 and is about 15 million light years away from the Earth. M 83 galaxy is the main member and at the center of the M 83 subgroup of galaxies. This subgroup together with the CentaurusA subgroup form the CentaurusA/M83 group of galaxies. Total there are about 50 galaxy members of this group, some grouped around the CentaurusA galaxy which is about 12 million light years away and some grouped around M 83 galaxy which is about 15 million light years away and together these two subgroups form one group called CentaurusA/M83 group of galaxies. This group is part of our Local Supercluster of galaxies, which astronomers also call it Virgo Supercluster of galaxies.
     Hydra constellation is notable by the fact that in this constellation lies the Hydra Supercluster of galaxies, which is the closest supercluster of galaxies to our Local Supercluster of galaxies. Hydra Supercluster contains only one cluster of galaxies (Hydra Cluster or Abell 1060) and a lot of groups of galaxies and chains of galaxies, the same as our Local Supercluster (or Virgo Supercluster) which contains only one cluster of galaxies (Virgo Cluster) and a lot of groups of galaxies and chains of galaxies. The Hydra Supecluster is about 200 million light years away from the Earth.