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Comet 2012 S1 ISON has been billed in some of the mainstream and scientific media as a potential "comet of the century". Wild predictions about it being as bright as the moon when it skims past the Sun's surface later in the year were everywhere after if was discovered.
ISON is currently a morning sky object and has just emerged from a period of being too close in the sky to the Sun to be seen by anyone. Recent observations by Hubble and others have suggested that it probably won't live up to that initial hype.
What we do know is that ISON is a first time visitor to the inner solar system and that on November 28th it will pass just 1.1 million km above the surface of the Sun. ISON may not survive the intense thermal stress of that encounter. If it does then it may, for a brief period, be a spectacular object if you catch it in the sky.
More about that another time.
In this post, I want to show you where ISON can be found in the months before that encounter with the Sun.
September to late November
The chart below shows the altitude and azimuth of the comet at the start of nautical twilight (when the Sun is 12 degrees below the horizon - about one and half hours before sunrise in the UK).