1 January 2020 at 6:26 pm #574488
The first major meteor shower of the year, the Quadrantids (010 QUA), should put on a good display this week, weather permitting. These medium-speed meteors hit the top of the atmosphere at 41 km/s and can give a peak ZHR of ~120 meteors per hour under optimal viewing conditions. From analyses of NEMETODE multi-year video data this is predicted to occur in the early hours of Jan 4 at 04:45 UT (solar longitude 283o.0)
[The IMO give a prediction of Jan 4 08:15 UT (solar longitude 283o.15), mainly based on data from 1992.]
During the nights around Quadrantid maximum the Moon displays its First Quarter phase, but it will be on its way to setting before the meteors’ radiant area in the constellation of Boötes (RA 15h 18m, Dec +49o.9) climbs above 20o in altitude.
The Quadrantids’ peak is a short-duration event lasting only a few hours; hence they are only seen at their best when the time of maximum coincides with their radiant being high up in a Moonless pre-dawn sky. They can produce sub-peaks of activity which vary from year to year, e.g. our video data has suggested some enhancement of rates a few days after maximum. This week observers in the British Isles are ideally placed to enjoy the show.
Whether you observe the Quadrantids visually, with a DSLR, video, spectroscopic or radio techniques, please report your results to the Meteor Section.
Attachments:4 January 2020 at 4:20 pm #581870Peter CarsonParticipant
Three of us from my local atsronomy club went to a fairly dark local site to view the Quadrantids between 04.00hrs and 06.00hrs. The weather was mixed with quite long periods of total cloud cover. Despite the cloud we recorded 49 Quadrantids which I class as a success.
I recorded 41 Quadrantids on my home meteor camera.
I’m a bit tired now!
Peter4 January 2020 at 7:27 pm #581871
I’m pleased that your efforts were rewarded with a good number of Quadrantid meteors. I’m sure the Meteor Section would be pleased to receive a formal report even though you observed under difficult conditions where the limiting mag and sky clarity varied so much.
Alex.5 January 2020 at 8:50 pm #581872Colin BridenParticipant
I monitored the Quadrantids on 200103-5 by forward scatter using the BRAMS beacon. From here it has a bearing of 137 deg. and range 600km.
The attached chart for Jan 03 shows a gentle rise after 2200 as the radiant climbed in the NE sky. The chart for the following 24h period of Jan 04 shows an odd drop in numbers between 0045 – 0145 followed by a steep rise from 0200 when the azimuth of the radiant was at around 47 deg – meaning that a high proportion of ionised trails lay normal to the line between transmitter and receiver, the ideal situation. Numbers held to a steady maximum centred on around 0400 before declining after 0515 to a low at about 0800 – when the azimuths of the radiant and BRAMS temporarily coincided, leading to a reduction in detected events. Then numbers slowly increased again to a second but slightly lower peak at around 1320. There was an abrupt drop at 1330 and by 2030 the radiant was on the northern horizon at an altitude of about 12 deg. Meteor numbers were then very low… they were probably mostly sporadics. The following morning to 1200 showed only comparatively low levels of activity in a normal diurnal curve.
At the time predicted for the visual maximum by the Nemetode analysis (0445) levels are certainly high. On the other hand the IMO predicted a short-lived maximum on Jan 04 at 0820 and the BAA on Jan 04 at 0900. Perhaps the rise and fall of a radio maximum at around 0830 was detected here – but the peak was lost to the ‘hollowing-out’ of the curve caused by the null detection point falling at the same time. This would be a long maximum, abruptly ended.
In all this I haven’t taken account of the changing altitude of the radiant as the maths is a bit complicated. I will have to think about that one!
Colin6 January 2020 at 11:48 am #581873
That’s a really nice set of radio data. During that time there is only a low level of activity from minor showers, and the ever-present sporadics, so we can assume the plots give a good approximation of Quadrantid rates.
The NEMETODE peak of 04:45 UT was derived from combining several years’ data and the individual years will have profiles that are affected by sub-peaks, brief drops in meteor flux, etc. The peaks suggested by the IMO and the BAA Handbook Meteor Diary were based on slightly later solar longitudes. The maxima derived from visual, video, radio and professional radar systems can differ in time because they can be detecting meteors from different sized meteoroid bodies and particle-sorting takes place in the stream, etc.
In some cases a bright meteor seen visually won’t have been detected on radio, and a very good radio trace wasn’t picked up by video cameras. I guess these are examples of optimal / non-optimal radio detection alignments.
We had awful conditions for visual and video work this week, so I’ll ask our radio observers to have a look at your extensive coverage.
I’m surprised we aren’t a nation of radio astronomers.
Alex.6 January 2020 at 2:32 pm #581874Colin BridenParticipant
Thanks Alex. For completeness I attach the chart for 200105 – which I should have done in the first place. My own feeling is that it does not show anything exceptional. I turned it off at 1200 as I needed the radio for something else!
Best wishes Colin8 January 2020 at 2:14 pm #581879Bill WardParticipant
Being away from home over the new year I was unable to do any spectroscopy. Given the weather I don’t think that would have been very successful anyway… ; – )
I did, however, attempt some visual observing from where I was, just outside Dundee, and for a brief spell I thought is was going to hold. Alas, no but I did see 2 Qua’s and 1 Spo in just under an hour. Nice to see the real thing from time to time…
My radio system kept vigil on my behalf and I was surprised to see that in terms of the maximum meteor count this years QUA’s pipped the 2019 GEM’s for the highest rate. 156 QUA’s 04-05UT verse’s 143 GEM’s also 04-05UT. Of course the GEM rate is pretty high over a much longer period…
I’ll put together some graphs at some point but it looks like it would have been a nice show given some clear skies.
- You must be logged in to reply to this topic.