(April schedule)

     Taurus constellation is winter constellation and it is in best position for evening observing in February when it is high on the southern sky.
     In December in the evening it is rising on the eastern sky, in January it is on the southeastern sky, in February it is in best position for evening observing high on the southern sky and in March it is on the western sky ready to set behind the horizon.
     We will observe it in April early in the evening when it is very low on the western sky and try to catch it before it sets behind the horizon.

Double and multiple stars

     Theta1/2 Tauri - is located inside the borders of the open star cluster called Hyades. Hyades is one of the closest open clusters from Earth, thus appears large on the sky. Its diameter on the sky is about 5 degrees, and it is visible with naked eye. Theta1 and theta2 are the most prominent members of the cluster and their visual magnitudes are 3.8 and 3.4. Theta1/2 is wide double star, that means we do not need to use telescope to see both stars separated, but we need binocular or sometimes we can see them on the sky resolved even with the naked eyes. That is the case with theta1/2 because they are separated on the sky by 337 arc seconds, or about 5.6 minutes. Their distance from the Earth is 154 and 150 light years. Their distance between each other is too big to form true physical binary star. Their colors are orange and white. Theta1 is orange giant and theta2 is white giant. Both of them are in fact spectroscopic binary stars.
     Struve 742 - This double star is located about 25 arc minutes east of the famous deep-sky object Crab Nebula or Messier 1. Or the star is less than one degree away from Zeta Taurus on the sky. The visual magnitudes of the stars are 7.1 and 7.5 and they are separated on the sky by 4 arc seconds. Their distance to the Earth is about 210 light years. Another catalog numbers for the stars are HIP 26328A and HIP 26328B.

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

     M45 - Messier 45. It is an open cluster of stars. The cluster is called the Pleiades. It is one of the closest open clusters to the Earth, thus it appears pretty large on the sky. The best views are with binoculars, because viewed through a telescope under big magnifications can not fit completely inside the field of view, so only part of the cluster can be viewed. Its apparent diameter on the sky is about 2 degrees. It lies about 450 light years away from the Earth. It contains over 1,000 stars. The brightest 15 stars can be seen even with naked eyes and they are hot and massive stars spectral class A and they are main-sequence stars, subgiants and giants. The cluster is about 100 million years old. Its real diameter is about 20 light years.
     Hyades - It is an open cluster of stars. It is also relatively close to the Earth and one of the closest open star clusters only 150 light years away. Because of this, it appears on the sky relatively large, over 5 degrees in diameter. It is close to Aldebaran on the sky and contains several hundred stars, but Aldebaran is not part of the cluster. The age of the cluster is about 600 million years. The diameter of the cluster is about 20 light years. Because it is so close to the Earth, is one of the most studied open cluster by professional astronomers. The cluster contains about 10 white dwarfs. That means that these stars when the cluster was formed were born with largest mass, they evolved first into giants and finished as white dwarfs. Several less massive members are currently red giants. 
     M1 - Messier 1. Its name is Crab Nebula. It is a supernova remnant. That is the material that has been ejected from the supernova explosion of a star. The supernova was Type II and was observed in 1054 year. At the beginning it was visible on the sky even during daylight. Now the supernova remnant have visual magnitude 8.4. It is about 6,500 light years away from the Earth. The current diameter of the ejected material is about 10-12 light years and the material is still expanding at a speed of about 1,500 km per second. In the center of the nebula is pulsar, a fast rotating neutron star about 30 km in diameter which spins 30 times per second. The mass of the remnant is about 5 Sun masses.
     The star which exploded was very massive with mass larger than 10 Sun masses and after the fusion process in its core stopped, the material started building it is core, while the fusion continued in its outer shells. When the built material in the core reached certain limit, the core material collapsed towards the center of the core creating at the same time massive explosion which threw the outer parts of the star into the space and what was left is the compressed degenerate remnant. That remnant will be neutron star if the original star had mass between 10 and 20 Sun masses, and the remnant will be black hole if the original star had mass larger than 20 Sun masses. The neutron star is composed completely of neutrons, it is about 20 km in diameter and its mass is about 2 Sun masses! Neutron stars have surface temperature of about 600,000 K and will cool slowly with time. If the original star had mass larger than 20 Sun masses, the formed neutron star will collapse further into a black hole. Neutron stars rotate rapidly in scale of milliseconds to up to several seconds, and are called pulsars. If the initial mass of the star is above 50 Sun masses, the star will collapse directly into black hole, without creating supernova explosion.   
     It is known that heavier elements than iron can only be produced during supernova explosion.