In accordance with Regulations 30 (Astrophysics) of the Natural Sciences Tripos (Statutes and Ordinances, p 386), the Director of the Institute of Astronomy gives notice that each candidate shall submit an essay on one of the following subjects:

• Dark matter on small astrophysical scales
• Type-Ia supernovae as cosmological probes
• Feedback in cluster cores

Each candidate must inform the Director by Friday, 16 March 2012 of the essay subject he or she has chosen, and must submit the essay so as to reach the Director by Thursday, 3 May 2012.