UCL Mathematical & Physical Sciences


Comet ISON

21 October 2013

Comet ISON

Comet C/2012 S1 - better known as ISON, after the initiative that discovered it - is currently plunging towards the Sun, and may become visible to the naked eye later this year. The brightness of comets is highly unpredictable and few ever become bright. The last comet to be clearly visible to the unaided eye in the UK was Hale-Bopp in 1997.

To the telescopes of the University of London Observatory, however, ISON is already clearly visible as it passes through the constellation of Leo. The image above shows the comet, with its tail now well developed, as it appeared in the early hours of 10 October 2013.

An image (below) taken by the Hubble Space Telescope the night before shows the comet's core has not broken up (something which frequently happens as comets approach the Sun).

ULO, part of UCL Department of Physics and Astronomy, is a major facility in Mill Hill, North London, used primarily for undergraduate teaching. Students learn practical astronomy through the use of the observatory's range of telescopes and instruments, ranging from modern computer-controlled instruments to historic telescopes well over a century old.

The observatory is also used for research, including exoplanet monitoring, though the atmospheric conditions and light pollution of the UK mean it is no longer a competitive location from which to carry out high precision observations.

Most major observatories today are located in high, dry and dark locations where atmospheric turbulence, humidity and light pollution are less of a problem - with some going further still by being located in space.

UCL astronomers, through the UK's participation in the European Southern Observatory, Roque de los Muchachos Observatory and the European Space Agency, are major users of these international facilities.

Comet ISON seen by ULO. Credit: Steve Fossey (UCL Physics & Astronomy/University of London Observatory)

Comet ISON seen by Hubble. Credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA)


High resolution images

Comet ISON seen by ULO

This image can be reproduced freely providing the source is credited

Comet ISON seen by Hubble

This image can be reproduced freely providing the source is credited