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Tue, 16 Feb 2016 - Mira (Omicron Ceti) is brightening rapidly

Omicron Ceti (Mira) has been brightening rapidly in recent weeks.

Mira is a pulsating red giant star and has an extreme brightness range between magnitudes 1.7 and 10.1. Not all maxima are equally bright however - on average, Mira reaches about magnitude 3.4 when at maximum. The period of variation is approx 332 days, which means that, in practice, the peak brightness occurs about a month earlier each year (as does the minimum brightness).

Mira passed through its latest minimum at the end of 2015 and an observation by Jonathan Shanklin showed it to be around mag 9.9 at the start of 2016. Further observations, by Jonathan and by Tony Markham, showed it to have brightened by more than two magnitudes by early February.

The latest observation - at mag 5.2 on Feb 15th, shows that the rapid rise in brightness has been continuin.

The only downside is that Mira is becoming less well placed for observation as the weeks pass. It is currently located in the south western sky at the start of the night and sets later in the evening. It will become lost in the evening twilight during March. This is particularly unfortunate given that the 2016 peak of Mira is predicted to take place in early April.

Nevertheless, the coming few weeks will allow more of the rise in brightness of Mira to be seen. You may even be able to spot it with the naked eye.

You can locate Mira using the finder chart shown below. Note that the "V" of the Hyades points towards the location of Mira, as do the stars of Pisces. The stars of the head of Cetus (labelled C, E, K, L) can also be a good location from which to "star hop" towards Mira. The chart also labels some nearby stars with which Mira's brightness can be compared. 

More information about Mira can be found in this guide

 

Added by: Tracie Heywood