Explore the Universe - Theta Tauri

The weather warmed up and it allowed me the opportunity to do some observing.  I spent the time taking a few pictures of Messier 42 - Orion Nebula and sketching the view of the double star Theta Tauri.  The two components of Theta Tauri are separated in space by approximately 4 light years making them an optical double.  This pair of stars is particularly interesting.  One of them is orange and the other is white.  At the telescope they are separated by approximately 5.62'; easily split with binoculars or a telescope.  Both of the stars have a spectroscopic binary.  A spectroscopic binary is basically a companion star that is too close to visually observe with normal techniques.

The light emitted from objects that are travelling very quickly towards us or away from us are either blue shifted or red shifted.  For example, if a red star is moving towards Earth very quickly, its light will seem to be closer to the blue side of the light spectrum.  This is known as the Doppler Effect for light.  It is similar to the idea of the Doppler Effect for sound, waves are lengthened or shortened depending on the relative velocity between the emitter and the observer.  A companion star that is very close to its partner typically orbits very quickly.  The spectrum of a binary system can be analysed.  When one of the stars is in its orbit moving away from Earth it will red shift and when it is in its orbit towards the Earth it will blue shift.  These spectrum shifts can be detected and it can be determined that there is indeed another star in the system.

Another interesting aspect of the Theta Tauri optical double is that is located in the Hyades open star cluster.  An open cluster is a group of stars that were formed from the same cloud of gas and thus are approximately same age.  A typical open cluster contains a few thousand stars and make for a great sight as observed from Earth.  The Hyades cluster is the closest open cluster to Earth at approximately 153 light years away.

Theta Tauri Observation Record

I was able to take an image of Theta Tauri and it is displayed below:

Theta Tauri (Pair on Left)

My first attempt to take a picture of Theta Tauri had a satellite fly through to disturb the image.  See below:

Theta Tauri with a Satellite

Tonight the asteroid Vesta reaches opposition.  This means it is on the opposite side of the Sun relative to the Earth.  It will be magnitude 6.2, barely visible under perfect skies in the country.  I will try to look for it later tonight if the clouds stay away.  I tried a few nights ago but became frustrated with the cold and the fact Vesta is more than 4 degrees away from a naked eye star.  If you are looking for Vesta, please see the sky chart at the following link:

http://simonjastronomy.blogspot.ca/2017/01/2017-week-3-january-9-21.html

Enjoy the warm weather and I hope you have the opportunity to look up!