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Wishing You Clear Skies

Suchita posted on 5th November

By Anindya Roy

I can bet when you were a kid you had, many a time, wondered about the universe, either by looking at the night sky, or while watching Star-Trek, and have wondered about our true origin, the truth about our existence, etc., etc…

If you have done that, you are bordering on becoming an amateur astronomer {and believe me, being an amateur astronomer is much more fun than being a professional astronomer}. I have friends who are amateur astronomers and are working for Planetariums, science centers, or making telescopes in their own garages. Most importantly, they are contributing to the science fraternity in various ways.

Essentially, you can be a lawyer, a hacker, or a banker, or whatever else, but you can still pursue the vastness of the celesta for your own knowledge and pleasure, or to contribute to science - passion and caffeine will take you through night after night. However, it's one thing to have a passion, and quite another to know where to start. Here are a few tips to get your going |

Buying Guide |


{Image courtesy:}

While a telescope isn't essential to learn about astronomy, it helps to be able to see what you are reading about. {Warning - without proper filters mounted on your scope and proper protection for your eyes, watching the sun can cause blindness. How quickly and severely will depend on how you use the telescope, so be super careful.}

Selecting a good telescope can be super challenging. There are many types of scopes, filters, mounts and lenses and for someone new, they can be pretty complex to identify. So here is what you should look for to start with |

Not too heavy or huge | In case of scopes, in the budget segment, bigger is better. But in NCR, you are not going to be able to get clear skies from your roof. Chances are you won't even get a roof to setup your scope. So you're going to have to travel. And hence, your scope has to be easy to pack, but big enough for you to see the miracles of the universe. A decent 5.0-inch aperture reflector should do the trick. Anything less than that would be more of a toy than a usable telescope.

Just to demystify, a 5.0-inch aperture reflector telescope is a telescope with a 5 inch diameter of the primary mirror. Don't confuse it with the tube length.

A wider field of view | For someone who is just starting with this hobby, it can be a challenge to find celestial objects through a scope. With greater magnification comes the challenge of pin pointing these objects. The apparent speed of the object moving out of your field of view {due to earth’s spinning} will increase in proportion to the magnification and, at the same time, the field of view will keep shrinking inversely proportionate to the magnification.

 So, when you are buying eyepieces for your telescope, make sure they are wide-field. They are bit more expensive, but give you more time to observe an object without realigning the scope.

Join a Club | Learning alone can be boring. That’s why it helps to join a group or a club. The two options we recommend in Delhi/NCR are |

  • AAAD | Amateur Astronomer’s Association Delhi is a 33 year old body and has recently registered as an NGO. The members meet at the Nehru Planetarium @ Teen Murti ever Sunday at 12:00 Noon. For more information you can check out their website here.
  • SPACE | Unlike AAAD {an NGO}, space is more of a commercial outfit and runs an Astro Club called Astronomica. SPACE also sells telescopes in India and does astronomy activities along with various schools. If you have bought a telescope from SPACE {the telescope wing is called Gnomon}, you automatically become a member of Astronomica. Or you can visit their website here to become a member. 

Where to Buy | By now you must be wondering where to buy scopes. Here is a quick list of places in India:

  • Run by Mr. Raju Patel, one of the finest amateur astronomers of India. This gentleman not only sells telescopes, but will also guide you and help you as much as possible when it comes to selecting the right scope.
  • Here, you will only find huge dobsonian telescopes, which are impractical to travel with. But, they are a great built and quality. Products of an Indian manufacturer, they are pretty reasonable as you don’t have to pay import duty on them. The gentleman {Mr Ajay Talwar} who runs this shop is another very well-known amateur astronomer in India. And he is among only two of the twan members in India. He is also a member of senior AAAD.
  • This is the telescope shop from SPACE and they are based in Delhi. They have a decent variety of self-manufactured and imported scopes and also offer online purchase.
  • Online: Of course, like any other commodity, you can also buy telescopes and eyepieces from and A simple search for telescope on any of the popular online shops will give you a lot of options. But if you are new to astronomy,  discuss your findings and choices with an Astronomy Club or someone who understands scopes before buying. This will make sure you don’t end up buying something that doesn't serve your specific purpose. 


Mathematics | 

Here are few basic units one should know before using or selecting scopes |

  • Primary Mirror | The biggest mirror you can see on a reflector telescope. This one is responsible for gathering light, so this thing will determine the limit of the faintest object your scope can capture. In this case, the bigger the better.
  • Focal Length | This is basically the distance between the primary and secondary mirrors,  and is somewhat apparent with the tube’s length. This factor guides how much magnification your scope can give you.
  • Eyepiece | This is the changeable component, which is used for varying the magnification of the telescope. Also, this is what you put your eye on.
  • The Calculation | The magnification of a telescope is calculated by dividing the focal length of the scope with the eyepiece’s focal length. So let’s say you have a telescope with 1200mm focal length, and you have a 20mm focal length eyepiece. Then the magnification you will get is 1200 divided by 20, and that should be equal to 60x.

The same scope with a 4mm eyepiece will give you a 300x magnification. But, as much you magnify, you keep losing on the amount of light gathered and the field of view. So with a smaller primary mirror, the brightness of the object will keep reducing as you keep increasing the magnification. This is called the F/ration of the scope, and can be calculated with the formula — f/ratio = focal length / aperture of primary mirror.


The Results |

jupiter-star-gazing-anindya-roy{Picture of Jupiter taken using a 5 inch reflector telescope and a webcam. Image Courtesy: Anindya Roy}


{Three Asterisms, King of Planets and a Dwarf Planet. Image Courtesy: Ajay Talwar}

Now as we have already established that a 5-inch aperture telescope should be ideal for a beginner, the question arises - what you can see through it? Here is a quick and simple list. This list is just to get you started on your hobby and catch the easiest targets, and is in no way the limit of your scope.

  • Craters of the Moon
  • Venus Crescent
  • Jupiter and its prominent features like the red spot and the tropical belts
  • 4 Galilean moons of Jupiter
  • Saturn and its ring
  • Andromeda galaxy
  • Many star clusters and binary stars

Before I conclude, here is a list of places near the NCR with clear skies |

  • Damdama Lake
  • Sariska
  • The abandoned mining zones in the Aravalli in Sohna Road, Gurgaon {near Pathways School}

And some not so near, but great places for observation |

  • Majkhali, Ranikhet
  • Hatu peak, Narkanda
  • Hanle Observatory, Hanle Village, Ladakh {Restricted Zone, needs prior permission}


Upcoming Event: Comet ISON |

The most recent and a potentially spectacular observation opportunity this month and in December could be the Comet ISON. This comet is supposed to have a huge and magnificent tail, potentially covering half the sky. As a result, there are two possibilities - one, of course, is that it will show up as a great view in the evening sky. And the other is that because it’s vaporizing fast, which is what causes the long tail, there is a possibility that it can disintegrate by the time it reaches perihelion {closest encounter to the Sun}.

However this may work out, we are very excited about the phenomena and hope to see some stunning activity in the sky. The comet can be seen today using optical aids like telescopes or power binoculars. But, around the time of the perihelion, {28th of November}, it should be visible as a bright object, even to the naked eye.

You can find all the information you need to catch the ISON Comet here.

About the Author | Anindya Roy is a hardcore geek by day and wears the amateur astronomer’s cap by night. He is an executive member of AAA Delhi and he has been practicing amateur astronomy and astro photography for the past 4 years. To know more about him or contact him, click here