Name of the Organization : Homi Bhabha Centre For Science Education
Name Of The Exam : Indian National Astronomy Olympiad – 2017
Document Type : Sample Question Paper
Subject : Astronomy
Year : 2017

Website : http://olympiads.hbcse.tifr.res.in/?page_id=1376#QS
Download Astronomy Model/Sample Question Papers : http://www.indianjobtalks.com/uploads/23-INAO2017.pdf

Indian National Astronomy Olympiad Astronomy Question Paper :
Duration: Three Hours
Maximum Marks: 100

Please Note :
** Please write your roll number on top of this page in the space provided.
** Before starting, please ensure that you have received a copy of the question paper containing total 3 pages (6 sides).
** There are total 7 questions. Maximum marks are indicated in front of each sub- question.
** For all questions, the process involved in arriving at the solution is more important than the answer itself. Valid assumptions / approximations are perfectly acceptable.Please write your method clearly, explicitly stating all reasoning.

** Blank spaces are provided in the question paper for the rough work. No rough work should be done on the answer-sheet.
** Non-programmable scientific calculators are allowed.
** The answer-sheet must be returned to the invigilator. You can take this question booklet back with you.

Please be advised that tentative dates for the next stage are as follows :
** Orientation Cum Selection Camp (Senior): 22nd April to 8th May 2017. This will be held at HBCSE, Mumbai.
** IAO selection camp (junior) will be held at Banglore and dates will be announced by NCSM later.
** Attending the camp for the entire duration is mandatory for all participants.

1. (15 marks) In each of the sub questions below, some astronomical phenomenon is shown through one or more images. Identify the phenomenon and describe it in 3-4 sentences.
(a) Image below is a long time exposure of a certain part of the sky. Explain what you see in the image.
(b) Explain what you see in the image below
(C) Each image below is showing same object but they are taken at different times. Explain what you see in the image.
(D) Two images below are showing same object but they are taken at different times. Explain what you see in the image.

2. On 22nd December, part of the shadow of a 30 m tall building falls on another building next to it. The separation between the two buildings is 30m and height of the shadow falling on the adjacent building is 24m.
(a) (2 marks) How long would the shadow be (on the ground) in the absence of this adjacent building?
(b) (5 marks) If this shadow is noticed at the local noon, what is the latitude of the place?

3. A star, at a distance of 1 pc from the Earth, becomes a supernova and reaches a maximum luminosity of 1011L?.
(a) (3 marks) What will be the maximum flux, Fsup, of this supernova at Earth?
(b) (3 marks) By what factor, R, will the total light flux on the Earth’s surface increase over that from the Sun alone?

(c) (4 marks) What will be the temperature, T, of the Earth when it reaches a new thermal equilibrium after the supernova? Assume the Earth to be a perfect black body and that it reaches a new equilibrium within a few days. Observations show that the average temperature of the Earth during the last century was 287 K.

(e) (5 marks) Assume that the number density of stars in theMilkyWay is 0.14 pc-3.There are 1011 stars uniformly distributed across the galaxy. Also assume that there is one supernova every 30 years and all of them have same luminosity. Find the probablity, P, of a supernova causing extinction on Earth in total life span of the Sun.