Perseid Meteor Shower,
28 July - 13 August 2020

The BAA Handbook for 2020 predicted that the annual Perseid meteor shower would extend from mid-July to late August of the year, peaking on 12 August with a ZHR [1] of 80. The Kappa Cygnids annual shower was also active around mid-August, with a radiant relatively close to that of the Perseids, but with a much lower forecast rate, ZHR=5.

Around the predicted peak of the Perseids, the Moon exhibited a waning crescent phase, meaning that moonlight would interfere with observations made in the early hours of the morning, when the radiant was at its highest altitude, most favourably placed for observing.

Observers

Four members of OASI reported observations as follows:

• James Appleton. Equipment: all-sky meteor camera operated in East Ipswich. ZWO ASI178mc camera with Fujinon fish-eye lens, CF2.7HA-L1, 1:1.8, 2.7 mm.
• Andy Gibbs. Equipment: Canon 1200D on fixed tripod, Samyang 14 mm f/2.8 lens, 30 s exposure at ISO 800. Images captured during an OASI meteor watch at Sutton Heath on 11 August. Other observers present were Mandy Gibbs and Paul Whiting, FRAS. Andy and Mandy arrived on site at 20:50 UT, Paul at 21:30 UT after being delayed in a diversion outside Felixstowe! Weather conditions were not ideal, the heat earlier in the day making the skies rather hazy, and the observers saw frequent flashes of distant lightning. Andy observed seven meteors, of which two were particularly bright: one at 22:03 UT in Draco (image below) and another at 23:40 UT in Cassiopeia, after the observers had packed their cameras away! The observers left site at 23:45 UT.
• Alan Smith. Equipment: all-sky meteor camera operated in Grundisburgh, north of Ipswich. Canon 1100D camera with 4.5 mm Sigma fisheye lens, f2.8, ISO 1600, 57 s exposures. The camera is fitted with a liquid crystal light gate with 10:90 closed:open ratio. The light gate segments the meteor trail, facilitating easy differentiation between meteors and satellites. (Long exposure images of the night sky often capture one or more satellite trails which, to the unpractised eye, can be mistaken for meteors.) The breaks in the trail are visible in several of Alan's images below.
• Paul Whiting, FRAS. Equipment: Nikon D3200 on fixed tripod, Samyang 14 mm wide-angle lens, f/2.8, ISO 1600, 6 s exposure. Observations made during an OASI meteor watch as above.

Observations

Note that each thumbnail image is cropped to the meteor trail and its immediate vicinity. Click on the thumbnail to obtain a wide-field view. Image times are provided below each thumbnail.

1. Alan, 28 July, 22:53-22:54 UT.		2. Andy, 11 August, 21:39 UT.		3. Andy, 11 August, 22:03 UT.		4. Paul, 11 August, 22:24 UT.
5. Andy, 11 August, 23:30 UT.		6. Andy, 11 August, 23:31 UT.		7. Alan, 11 August, 23:39:27-3:40:24 UT.		8. James, 11 August, 23:39:38-23:40:08 UT.
9. Alan, 12 August, 02:17:45-02:18:42 UT.		10. James, 12 August, 02:18:11-02:18:41 UT.		11. Alan, 12 August, 21:56:51-21:57:48 UT.		12. Alan, 12 August, 21:58:52-21:59:49 UT.
13. James Appleton, 12 August, 21:59:35-22:00:05 UT.		14. Alan, 12 August, 22:34:12-22:35:09 UT.		15. Alan, 12 August, 23:43:51-23:44:48 UT.		16. James, 12 August, 23:43:55-23:44:25 UT.
17. Alan, 13 August, 00:08:04-00:09:01 UT.		18. James, 13 August, 00:08:13-00:08:43 UT.		19. Alan, 13 August, 00:11:05-00:12:02 UT.		20. James, 13 August, 00:11:16-00:11:46 UT.

Observational details:

1. Alan. 28 July 2020, 22:53-22:54 UT. A faint Perseid in Camelopardalis. This was the first Perseid of 2020 captured by a member of OASI.
2. Andy. 11 August 2020, 21:39 UT. A Perseid in Ursa Minor.
3. Andy. 11 August 2020, 22:03 UT. A Perseid in Draco.
4. Paul. 11 August 2020, 22:24 UT. A meteor in Cassiopeia displays a bright flare towards the end of its trail. The meteor was neither a Perseid nor a Kappa Cygnid, but a sporadic, its path running at right angles to radials from the radiants of both showers.
5. Andy. 11 August 2020, 23:30 UT. A Perseid on the border of Cassiopeia and Camelopardalis.
6. Andy. 11 August 2020, 23:31 UT. A Perseid on the border of Cygnus and Cepheus.
7. Alan. 11 August 2020, 23:39:27-23:40:24 UT. A very faint Perseid in Pisces.
8. James. 11 August 2020, 23:39:38-23:40:08 UT. The above Perseid again.
9. Alan. 12 August 2020, 02:17:45-02:18:42 UT. A Perseid in Aquila.
10. James. 12 August 2020, 02:18:11-02:18:41 UT. The above Perseid again.
11. Alan. 12 August 2020, 21:56:51-21:57:48 UT. A faint Perseid in Andromeda.
12. Alan. 12 August 2020, 21:58:52-21:59:49 UT. Faint traces of a bright meteor in the region of Serpens Caput. The meteor was a sporadic, not a member of the Perseid shower. Unfortunately, the object was largely obscured by cloud.
13. James. 12 August 2020, 21:59:05-22:00:05 UT. A stack of two 30 s frames captures the above meteor more effectively. The flare near the end of the trail has illuminated nearby cloud. Note that the orientation of the trail appears considerably different to Alan's image, implying that the meteor penetrated to a relatively low altitude before disintegrating.
14. Alan. 12 August 2020, 22:34:12-22:35:09 UT. A faint Perseid in Andromeda.
15. Alan. 12 August 2020, 23:43:51-23:44:48 UT. A Perseid in Lacerta.
16. James. 12 August 2020, 23:43:55-23:44:25 UT. The above Perseid again.
17. Alan. 13 August 2020, 00:08:04-00:09:01 UT. A Perseid in Andromeda displays a trail and terminal flare. Unfortunately, the image is compromised by cloud and haze.
18. James. 13 August 2020, 00:08:13-00:08:43 UT. The above Perseid again.
19. Alan. 13 August 2020, 00:11:05-00:12:02 UT. A Perseid in Aries. Alan is an international member of the Dutch Meteor Society (DMS), and observing stations of the DMS at Leiden, Bussloo, Ermelo, Wilderen and Twisk also imaged the meteor. DMS observers estimated the magnitude of the object as -8.5, so it would have been visually spectacular were it not for the cloud and haze over East Anglia at the time.
20. James. 13 August 2020, 00:11:16-00:11:46 UT. The above Perseid again. Unfortunately, the image suffers from false colour, in the form of a short violet streak running parallel to the true path of the meteor.

Triangulation of Path of Meteor Through Lacerta

The two images of the meteor in Lacerta on 12 August (images 15 and 16 above) contain sufficiently many background stars to enable the apparent coordinates of the meteor trail to be estimated. This in turn enables the path of the object to be estimated by triangulation, using the method of [2], with implementation based on [3] (slightly modified). The resulting path of the meteor is shown below. The path becomes visible off the coast of north Suffolk at an altitude of 122 km, travelling due SW. There is a bright flare off the coast of Bawdsey at an altitude of 81 km, and the trail terminates slightly further on at an altitude of 76 km.

Footnotes And References

[1]	The ZHR (Zenithal Hourly Rate) is the standard measure for meteor activity. It corresponds to the number of meteors that a hypothetical observer would record in an hour with the radiant at the zenith.
[2]	Zdenek Ceplecha, "Geometric, Dynamic, Orbital And Photometric Data On Meteoroids From Photographic Fireball Networks", Bull. Astron. Inst. Czechosl. 38 (1987), 222-234.
[3]	Denis Vida, 2016, Python programme for meteor triangulation, https://github.com/CroatianMeteorNetwork/CMN-codes/blob/master/triangulation/MeteorTriangulation.py.