How to See Sirius With A Telescope?

Photo: The Dogstar (Sirius A) and its Pup (Sirius B) 

Sirius, also known as the Dog star, is the brightest star in the sky found in late winter and spring. It has a tiny companion named Sirius B known as Pup which is basically a white dwarf star. Both of them make a binary star system that is visible through your telescope. Most of the time, they are seen combinedly as one glowing star as it is hard for the telescopes to detect their duality. 

The main star Sirius is twice as massive as the Sun whereas the dwarf star Sirius B is around the same volume as the Earth though has the same mass as the sun. Besides, the luminosity of Sirius B is 10,000 times less than Sirius A.

Before starting, choose a Star map, it will help with Sirius observation.

There are several star charts that can show you the location of Sirius that night. ‘Clear Sky Chart site’ is an app that helps you to find the best location near you to observe the star by analyzing the weather condition and airspeed. If it forecasts vigorous turbulence, there is no point to try. Plan for observation when the seeing forecast is merely good at least.

How to find Sirius A & Sirius B?

  • Try to locate Orion at first. 
  • Bright red Betelgeuse is on top.
  • In the middle, you will find its famous belt composed of three bright stars. Sirius is just upward the belt.
  • Follow the stars left and down. There you will get a distinct blue-white color bright star, Rigel. Nearby you will find Sirius and its companion Sirius B.
  • Take a high-power eyepiece, adjust it in the scope, and point the tube towards 

What is the best time to observe Sirius?

In the Northern Hemisphere, the best time to observe Sirius B is in most parts of January and February i.e in winter. During this time Sirius is at its highest in the sky in the early hours. It is important because the viewing experience could be worse when Sirius is too low in the sky due to turbulence near the horizon. On 1st January, the best time is at midnight, on 1st February, around 10 pm, and on 1st March at around 8 pm. As April comes, Sirius begins to get down shortly after sunset.

Photo: Separation between Sirius A and from Earth on a 50-year cycle.

The two stars orbit each other at around 20 AU (astronomical units) which is the same distance between the sun and Uranus. It is almost 3 to 11 arc seconds on a 50-year cycle. In this year 2022, these two are at their highest separation. So this last month of 2022, is the best time to see these two stars and look for them after midnight. 

3 Tips to observe Sirius in the best way.

  • Sirius B will be visible throughout the decade the 2030s, with even a 4-inch telescope. 
  • Theoretically, Sirius B is just outside the bundle of the brightness of Sirius A. However, in reality, it is mostly hidden by the glare of Sirius. But for a few moments, you will be able to see the round pattern of Sirius B.
  • If your eyes get tired of searching for Sirius B, take a break and observe the other stars and then try again. If you can not see it, try again the next day.

What can you see on the Sirius with a telescope?

  • You will find another binary star Rigel and its companion Rigel B.
  • Sirius B or the Pup is right there. 
  • Alnitak (Zeta), Alnilam (Epsilon), and Mintaka (Delta)are the three bright stars on the belt of Orion.

What telescope to see Sirius?

Celestron RASA 8″, Meade LX200-ACF 8″ f/10 Telescope, and Orion SkyQuest XT8 Classic Dobsonian are great telescopes to see Sirius. A list of telescopes has more telescope options that can see Sirius very clearly.

What size telescope to see Sirius?

With a 100mm telescope, you can spot Sirius but the views are not sharp. An 8-inch telescope with at least 300x magnification can make a great image of Sirius. But to detect the Pup, you need a 10-inch telescope with at least 500x magnification. The larger scopes will show sharper images.

What magnification is required to see Sirius?

You should try the highest power available on your telescope. Use 300x magnification for a 6-inch telescope and 400x magnification for an 8-inch scope. Use more magnification for the larger scope.

Enjoying Sirius? Here are other things to see with your telescope

Viewing Sirius through a telescope is an amazing experience. However, your telescope can show you more gems of the night sky. All the planets of our solar system, the sun, satellites, asteroids, comets, stars, nebula, and myriad night sky objects are waiting for you to show their amazing appearance. Grab a telescope and hunt for them. ‘List of things to see with a telescope’ can be a guide to knowing where and how to find different objects with your telescope.