Mensa (Shail)
Mensa, resembles the shape of a table mountain, when stars in this constellation are imaginarily connected!
Where should I see…Chamaeleon and Volans, is the constellation which is towards west of Mensa
constellation. If you move your eyes towards east, you will see another constellation named Hydrus and Reticulum. In the North and South of Mensa, you will find Dorado and Octans constellations respectively. Mensa is near South Pole, and so is fully part of Southern Hemisphere.
It covers up 153 square degree area of the sky. Area wise it is 75th largest constellation in the sky.
When and What can I see…We cannot gaze at this beautiful table mountain shape of Mensa constellation as
seen from India.
All you need is your naked eyes other than clear skies to see 26 stars of this constellations, as they are the one which are brighter than the lower limit of our naked eyes (i.e. 6.5 apparent magnitude) to see faintest stars.. The brightest star of this constellation is Alpha Mensae.
Constellations are made up of single, binary (apparent and absolute), multiple and variable stars. Out of total 26 stars of different types, here is the list of 20 brightest stars as per their nature:
| Binary / Multiple Star system | Variable Stars | Binary and Variable Stars | Single stars |
| 1 | 4 | – | 15 |
As per Hindu mythology, there are no such known stories for this constellation.
Deep Sky Objects…
Large Magnellic Cloud || Irregular Dwarf Galaxy
NGC 1987 || Globular Cluster
PKS 0637-72 || Quassar
All the stars that we see naked eyes, all belong to our own, Milky way galaxy (Akash Ganga Tara Vishv). Bright stars can be seen naked eye and faint one through telescope. But the curtain of sky that we see in 2D is actually a huge universe we are talking about, with 3 dimension. There are many nebulous objects visible in every constellations. They differ widely by distances and nature. Like Emission Nebula, Reflecting Nebula, Absorption Nebula, Star Birth Nebula, Supernova Remnants (SNR) and Open Stars cluster which are within the disk of our own Milky Way galaxy. Globular cluster are also found, which are in the halo of our galaxy and some most distant objects like galaxies are also visible through telescope. Such objects are defined as “Deep Sky Objects”.
In this constellation there are 85 such different types of Deep Sky Objects observed. Below is the list of 20 brightest Deep Sky Objects:
| Galaxy | Open Cluster | Globular Cluster | Nebula | Supernova Remnant | ||
| Naked eye visibility | – | – | – | – | – | |
| Visible through Telescope | – | 8 | 8 | 4 | – | |
| – | 8 | 8 | 4 | – |