Thu, 31 Dec 2015 - Getting Ready for the Quadrantids
The new year starts with a favourable return of the Quadrantid meteor shower. Here are some tips to help you see the Quadrantids at their best.
Which will be the best night ?
Quadrantid activity can be seen throughout the first week of January. Most of the activity occurs however during a sharp peak only a few hours across. In some years, this peak occurs during daylight hours. In others it occurs with the Quadrantid radiant low in the sky and/or with a bright Moon in the sky. Only occasionally will the peak occur when the radiant is high in the night sky and without serious moonlight interference.
is that one such year is 2016 ... more
or less. Peak activity
is predicted for around 7am GMT
on the morning of January 4th.
This is at the end of the night in the UK so, although we will see the rates rise to peak level, the decline post maximum will occur during twilight and daylight. Observers in south east England may also find the sky is getting a bit bright by 7am, but observers further west and further north should still have quite dark skies. However, even if you are unable to observe as late as 7am, there is still be possibility of seeing rates rising from around 4am onwards ... providing of course that you can drag yourself from your warm bed!
More good news is that, as the accompanying graph shows, is that the Quadrantid radiant is highest in the sky late in the night.
Yet more good news is that moonlight will only be a minor problem. On Jan 4th, the crescent Moon is only 31% illuminated, is located near the Virgo/Libra and doesn’t rise until after 2am.
Where is the Quadrantid radiant?
Quadrantid meteors appear to radiate outwards from an area of sky once allocated to the now defunct constellation of Quadrans Muralis. This area lies in northern Bootes, to the left of the handle of the Plough (to be more precise, it is at RA 15h20m, Dec +49). The circle in the accompanying diagram shows its location of the radiant.
When to observe each night
The higher that the radiant is in the sky, the more Quadrantids will be seen. The radiant is rather low in the northern sky during the evening hours but, as the earlier graph showed, it starts to gain altitude in the north east after midnight. It is highest in the sky, above 70 degrees altitude, around dawn.
Very few people will have the stamina to observe from dusk until dawn. Although meteor watches during the evening hours are useful, the most productive time will be in the hours leading up to dawn. However, to make use of these you will need to be able to drag yourself from your warm bed!
How many Quadrantids will you see?
Published Quadrantid ZHRs cover a large range, from about 80 up to in excess of 200. It is unclear as to the extent that these differences are due to year to year changes in Quadrantid activity levels or are merely due to some analyses near the peak having calculated ZHRs based on intervals of less than an hour. Observed rates will in any case be somewhat lower than these ZHR values. You can hope to see observed rates similar to peak Perseid levels just before dawn brightens the sky on the morning of Jan 4th. Early in the night and on other nights, observed Quadrantid rates will be lower, probably a few per hour.
Where to observe from
Two main factors will impact the number of Quadrantids that you will see. The first is how much of the sky you can see. Choose a location that has a clear view of the sky so that meteors aren’t “lost” behind trees, etc. The second, and most critical, factor is the darkness of the sky background. If the sky is lit up by nearby streetlighting , the fainter Quadrantids will be “lost” against this bright background. Therefore, try to find as dark an observing site as possible.
Where to look in the sky
Don’t look at Quadrans Muralis (even if you know where this defunct constellation used to be!) Any meteors that appear there will be approaching almost head on and so their paths, projected against the star background, will be hard to spot. It is better to observe an area of sky around 30-40 degrees away from the radiant and about 50 degrees above the horizon ... and keep the Moon out of your field of view. One possible area of sky to choose would be near Polaris.
January nights with clear skies tend to be rather cold. Make sure that you are well wrapped up against the cold, paying particularly attention to your feet, knees, hands and head. You want to be focussing your attention on seeing meteors and not be distracted by the cold!
Let us know what you see: Please mail your reports and images to firstname.lastname@example.org.
Added by: Tracie Heywood