Astronomy Now - January 2021

Highlights: The Quadrantids. Observe a strong

meteor shower

When: peaks 2/3 January

What’s special: Following hard on the heels of December’s glorious Geminid meteor shower is the
Quadrantids, another strong and reliable shower that opens the meteor year in ne style. e
Quadrantids are already one of the year’s major showers with the potential to become even more
special, with rates at maximum rivalling those of the Perseids and Geminids. However, the
Quadrantid’s comparatively narrow peak of around six hours, when activity is at its strongest, means
more often than not it falls short. Nevertheless, it’s reasonable to expect rates in excess of 50 meteors
an hour at a dark site. One major caveat for 2021 is the disrupting presence of the interfering glow
from a waning gibbous Moon. More on the plus side for observers at mid-northern latitudes is that
the radiant rides favourably high when at its highest point in the sky towards dawn. is is essential
to provide a huge area of sky to encompass the meteors that’s also well clear of the worse ravages of
atmospheric extinction.

How to observe: To get the best out of any meteor shower one needs to know roughly what part of
the sky to watch in order to see the maximum number of meteors. e paths of shooting stars that
belong to a particular shower can be traced back to a particular part of the sky known as the ‘radiant’.
Naturally, showers are named for the constellation in which the radiant is found; Gemini hosts the
Geminids, Perseus the Perseids, and so on. So where do we look for the Quadrantids?

e shower’s name comes from the obsolete constellation of Quadrans Muralis, which occupied what
is now the northern part of Boötes, near the end of the Plough’s handle. (More precisely, the
Quadrantid’s radiant lies roughly been magnitude +4 theta (θ) Boötis and magnitude +3.9 tau (τ)
Herculis – RA 15h 18m, Dec +49.5 degrees.)

In 2021, meteor experts predict that the peak of the Quadrantid meteor shower will occur at around
14: 30 UT on 3 January. Unfortunately, the timing is not favourable for the UK, but observers can
expect to see rates increasing on the night of 2/3 January. e radiant climbs late-evening in the
north-north-eastern sky and reaches a reasonable elevation of around 30 degrees by 1am GMT. As
previously mentioned, an 84.2 per cent-illuminated waning gibbous Moon, lying among the stars of
Leo, rises well ahead of the radiant. Its strong glow will drown out many of the Quadrantid’s
plentiful fainter meteors, though the shower does produce its fair share of bright events.

Unexpected activity can break out anytime for any meteor shower. e Quadrantid’s ZHR (Zenithal
Hourly Rate; the likely rate of meteors seen by a single observer assuming the shower’s radiant lies at
the zenith, i.e. overhead, in a dark sky) for 2021 is quoted as 120, but the ZHR uctuates. In 2012,
the ZHR reached only 80, but it increased to probably exceed 150 in a particularly strong return in

2014. Indeed, a storm was reported for a brief period on the day after the main peak! e only way
      not to miss anything is to wrap up warm and head out in the cold January night to see for yourself!

A composite image of the 2014 Quadrantids.

The Quadrantid meteor shower radiant lies in northern Boötes.

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Highlights: The Quadrantids. Ob...

January 2021

Astronomy Now