Radio Astronomy

June Meteors

No major activity in June , the June Lyrids the most active around the 15th/16th of June, the peak is distinguishable on the daily count plot. The peak activity around the 10/11th, is probably the combination of the Theta Opiuchids and Saggitariids.  The rest of activity during the month a combination of the many minor showers present.

The dip in the daily rate on the 6th is due to Graves being off line between 01-05 hrs. The activity has dropped of to about 50 meteors / day towards end of month and has continued at this rate into July which is a relatively “quiet” month.

The plot is similar to the daily plot from 2017, although rates lower( this is probably dependent upon the density of the debris field the earth passes through )

I’ve listed the showers for June below as are the daily and hourly plots for June 2018 and the daily plot for June 2017.

Moderate Activity:

Radiant Duration Maximum
June Lyrids June 10-21 Jun. 15/16

Minor Activity:

Radiant Duration Maximum
June Aquilids June 2-July 2 Jun. 16/17
June Boötids June 27-July 5 Jun. 28/29
Corvids June 25-July 3 Jun. 27/28
Tau Herculids May 19-June 19 Jun. 9/10
Ophiuchids May 19-July 2 Jun. 20/21
Theta Ophiuchids May 21-June 16 Jun. 10/11
Sagittariids June 10-16 Jun. 10/11
Phi Sagittariids June 1-July 15 Jun. 18/19
Chi Scorpiids May 6-July 2 May 28-Jun. 5
Omega Scorpiids May 19-July 11 Jun. 3-6
June Scutids June 2-July 29 Jun. 27/28

Daylight Activity

Radiant Duration Maximum
Arietids May 22-July 2 Jun. 7/8
Zeta Perseids May 20-July 5 Jun. 13/14
Beta Taurids June 5-July 18 Jun. 29/30

May Meteors.( Based on Graves Radar)

The main meteor shower in May is the Eta Aquarids,  it is however not the only shower and there are several daylight showers as well. The effect of this is for the “peak” of activity not to be situated around the 5th / 6th of June but elsewhere. This can be clearly seen on the daily and hourly plots for the month both for this year and last year.

Major Activity:

Radiant Duration Maximum
Eta Aquarids (ETA) April 21-May 12 May 5/6

Minor Activity

Radiant Duration Maximum
Epsilon Aquilids May 4-27 May17/18
May Librids May 1-9 May 6/7
Eta Lyrids May 3-12 May 8-10
Northern May Ophiuchids April 8-June 16 May 18/19
Southern May Ophiuchids April 21-June 4 May 13-18

 

Daylight Activity

Radiant Duration Maximum
Epsilon Arietids April 25-May 27 May 9/10
May Arietids May 4-June 6 May 16/17
Omicron Cetids May 7-June 9 May 14-25
May Piscids May 4-27 May 12/13

Successful detection of meteor shower by radio scatter at Damian’s house Streethay from Graves’ radar

After Peter Hill’s brilliant talk at the last RAG meeting, we were both motivated to pull out Andy’s radio meteor kit and give it a try. In the past Andy has had real problems getting it working at his house and we don’t know why. First step was to try it elsewhere – Damian volunteered his house for the task today.

A useful day of testing Andy’s portable meteor detecting equipment…

Picture contributions from Andy, Damian and Julie (+ annotations!)

Setting up at Damian’s house…

Dancing around the Maypole!

Getting there…

Done…. and ready to go!

Andy bought along a selection of aerials – in the end he chose the simplest and cheapest off the shelf one rather than the hand-made and carefully cut (length to frequency by Bill from Lichfield) versions below….

Our chairman with his radio equipment at Damian’s house (below):

Peter used his FunCube Dongle for his detections. To simplify this initial trial, Andy bought along for this test his Yaesu FT817 portable radio. We used Peter’s settings file and a cheap off the shelf aerial and cable and a car battery to power everything.

The aerial poles are an ex-military carbon fibre Clansman kit – 5.4m high! Andy initially bought these several years ago to use with his Radio Jove Jupiter radio-observing radio and aerials but they are also very useful for meteor detection!

Clansman aerial mast kit:

Immediate success with the military aerial at full height !

Screenshots from Spectrum Lab showing meteors in Damian’s garden:

Success was at the Graves’ frequency 143.049 MHz (Upper side band):

We then tried reducing the height of the aerial to roughly the same height as the aerial on the roof of my shed (2.4m) where my current aerial is located.

We found we were still able to detect aerials roughly every minute or so. Their peak magnitude did not seem to be as large as when the aerial was twice as high………so reduced height = less meteors and reduced magnitude of detection.

Next step was to take the set-up which we had just proved worked back to Andy’s house to see if it worked in his garden to test the theory that he lives in a radio black spot which explains his difficulties over so many years.

The following are screenshots from Spectrum Lab in Andy’s garden showing meteors:

Next steps for testing Andy’s meteor observing problems in his garden:

1. Test the same kit as above with different heights of aerial.

2. Erect aerial above and record meteors over 24 hours.

3. Try recording meteors with lower height aerial in Andy’s garden during meteor shower – no meteor shower major or minor today in standard lists.

4. Use aerial on top of shed with Yaesu radio to see whether meteors are detected.

5. If yes to 4 then try changing radio to FunCube Dongle to see if still works.

6. Try kit as above in Andy’s and Damian’s garden but this time using FunCube Dongle rather than Yaesu radio.

For future reference, we came up with this list of equipment we need to take with us on future radio meteor observing sessions, out of the home location (such as outreach sessions at the forestry centre):

  • Yaesu FT-817 radio – make sure power cable, audio cable in the box.
  • Laptop with spectrum lab and settings files.
  • Computer hood or box so can see screen in sun
  • Portable table and chairs or stools
  • Car battery
  • Inverter
  • Multiple plug adapter so can plus both laptop and radio into the inverter (at least two plugs)
  • 12V power supply for radio – alternatively 12V battery
  • Mallet to hammer in pegs for aerial
  • The C-Clamp on the aerial is larger than the Clansman aerial poles so need piece of wood to go in between C-Clamp and aerial.
  • Clansman aerial poles kit in green bag – make sure 6 poles, 2 x round discs for attaching the guide ropes, 3 x metal strips wrapped with guide ropes x2 per strip, 5 x pegs.
  • Extension cable for aerial (may not be needed depending on aerial used).
  • Aerial – today we used off the shelf Yagi for UHF – cheap and cheerful but effective! If this one is used then extension cable not required as it has long cable with it.

We then returned to Andy’s house to try the same set-up at his… plus a beer!

Damian and Andy

April Meteors

The main shower in April is the Lyrids, but as the table below shows there are other showers present as well.

Major Activity:

Radiant Duration Maximum
Lyrids (LYR) April 16-25 Apr. 22

Minor Activity:

Radiant Duration Maximum
Tau Draconids March 13-April 17 Mar. 31-Apr. 2
Librids March 11-May 5 Apr. 17/18
Delta Pavonids March 21-April 8 Apr. 5/6
Pi Puppids (PPU) April 18-25 Apr. 23/24
April Ursids March 18-May 9 Apr. 19/20
Alpha Virginids March 10-May 6 Apr. 7-18
April Virginids April 1-16 Apr. 7/8
Gamma Virginids April 5-21 Apr. 14/15

Daylight Activity:

Radiant Duration Maximum
April Piscids April 8-29 Apr. 20/21

The total meteor activity detected for April was 1790.

The average daily rate was 60 and the average hourly rate 2.5

The max hrly rate was 11  during the hours of 9 & 11 on 30th April

The max dly rate was 93 on 23rd April with hourly counts of 10 during the hours of 4, 9 & 11.

Maximum activity for the Lyrids occurred during daylight as did a lot of this months activity.

The daily rate graph and hourly rate graph are listed below, the Lyrid max is marked on both, the daily rate for 2017 is also included for comparison, it would appear more meteors were detected this year. The month of May brings the Eta Aquarids over the weekend of the 5th/6th, which will be competing with a bright waning Gibbous moon.

Pete H

 

March Meteors

March is not blessed with a conspicuous meteor shower but there are plenty of minor showers overlapping.

Minor Activity

Radiant Duration Maximum
Eta Draconids March 22-April 8 Mar. 29-31
Beta Leonids February 14-April 25 Mar. 19-21
Rho Leonids February 13-March 13 Mar. 1-4
Leonids-Ursids March 18-April 7 Mar. 10/11
Delta Mensids March 14-21 Mar. 18/19
Gamma Normids (GNO) March 11-21 Mar. 16/17
Eta Virginids February 24-March 27 Mar. 18/19
Pi Virginids February 13-April 8 Mar. 3-9
Theta Virginids March 10-April 21 Mar. 20/21

Daylight Activity

Radiant Duration Maximum
March Aquarids February ??-April ?? Mar. 15-18

The total meteor activity recorded for the month using the fundongle pro+ on the Graves frequency was 1116, there was a daily average of 36 with an hourly average of 1.5 The maximum daily count was 60 recorded on 19th March as was the max hourly count of 13.

This peak activity coincided with the peak activity of the Beta leonids, delta mensids and eta Virginids. Other minor peaks can be identified using table above.

A post on the UK Radio Meteor discussion group on the 19th flagged up a long duration event picked up by an observer at Emsworth in Hampshire., I didn’t find any visual reports of this daytime event.

Checking my logs this event had also been recorded at Barton, although spread across two screens.

The event was also recorded in Lincoln ( note the vertical, rather than horizontal waterfall screen)

Also recorded in Loughboro’

April is now with us and as well as several minor showers there is the Lyrid shower to look forward to over the 21/22 of the month , peak 11:00 – 22:00 BST on 22nd April. Moon in its first quarter should not cause any problems and for Lunar observers the Lunar X and V are at peak visibility around 21:40 BST on sun22 April.

 

clear skies

 

Pete H

February Meteors.

February is not noted for its meteor showers, only a handful of minor showers and some daytime showers.

Minor Activity

Radiant Duration Maximum
Aurigids January 31-February 23 Feb. 5-10
Alpha Centaurids (ACE) February 2-25 Feb. 8/9
Beta Centaurids February 2-25 Feb. 8/9
Delta Leonids (DLE) February 5-March 19 Feb. 22/23
Sigma Leonids February 9-March 13 Feb. 25/26

Daylight Activity

Radiant Duration Maximum
Capricornids-Sagittariids January 13-February 28 Jan. 30-Feb. 3
Chi Capricornids January 29-February 28 Feb. 13/14

The radar reflections using Graves, gave a total count of 1140 meteors, with an average daily count of 41 and average hourly count of 2 (1.7), the max hourly count observed was 7 and max daily count 62. The contributions to activity from the Centaurids , Leonids and Capricornids are discernible on the charts below. March is another month of no notable shower, but lots of minor showers.

Clear Skies

Pete H

 


Jocelyn Burnell Lecture at Jodrell Bank Discovery Centre

Since retiring a year ago I have rekindled my casual interest in astronomy by taking an online Astronomy GCSE course, joining the RAG and visiting places of astronomical interest, such as the world famous radio telescope at Jodrell Bank, Cheshire. During my visit there on 1 February 2018, a famous astronomer, Dame Jocelyn Burnell was delivering a lecture on her discovery of pulsars in 1967.  She’s famous not only for this discovery but also for her controversial exclusion from the Nobel Prize in Physics for the discovery.

Jodrell Bank Radio Telescope

Although the radio telescope is an impressive feat of technology and engineering, the highlight of my visit was the lecture. The event sold out shortly after Christmas and so all 200 seats in the auditorium were occupied, she was obviously very popular with the astronomer fraternity.

She explained that the objective of her PhD was to discover more quasars (quasi stellar radio sources) but first she had to build her own radio telescope, and for this, like all fellow astronomy students back then, she was given a tool-kit; rugged pliers, wire snips and a screwdriver! Cambridge still used valves in their amplifiers, although transistors were available at the time! The new telescope covered several acres, used miles of cable, took 2 years of working in all weathers to complete and worked first time! It was a fixed structure, with no control over its direction.

Launch of IYA 2009, Paris - Grygar, Bell Burnell cropped.jpg                                                                                   Dame Jocelyn Burnell                                                                                 

She confessed to being so surprised at getting into Cambridge University that she was sure the University had made a grave mistake and she would be thrown out as soon as this was discovered. In the meantime, she would work flat out to get as much done before this happened. This, she said, was the incentive that drove her to work long hours and to accept the brunt of supervisor’s caustic comments.

The main task was inspecting miles of printout for anomalies and it was not long before she found one…then another…and another. It was a sign of the times that her supervisor (and recipient of the Nobel Prize) was arrogantly dismissive of her excitement and was told the source was not from outer space because of the pulse’s incredible regularity, it must be man-made interference.  And so began a laborious period of eliminating all possible spurious radio sources; badly suppressed vehicles, radio waves reflected from a corrugated iron shed roof and even from the Anglian Police Force radios. With an ironic smile she recalls telling her supervisor that if a vehicle was to blame it was setting off at 4am, then at precisely 4 minutes earlier each day and had been doing so for the past 2 weeks! The source was clearly emanating from the same point on the celestial sphere. With wry humour, she told how she played along with notion that it could be a man-made source, labellng the first anomaly or ‘bit of scruff’ as LGM-1; Little Green Man-1.

She recounted that to check the recurrence of one source she would need to be using the telescope at 2am but she was due to go to her home in Ireland with her fiance that day to announce their engagement…she duly stayed up all night and also made it home. Such was her determination.

With standard plotting paper speed the anomalies were too compacted to be analysed accurately, so the paper speed had to be  increased. But this meant each paper roll would last only 20 minutes. The solution was to only increase the paper speed just before the predicted time for the repeat showing of the anomaly. Unfortunately, this meant going out to the telescope control shed in the middle of the night sometimes.

We now know (partly due to astronomer Sir Fred Hoyle) that the anomalies are pulses from neutron stars rotating very rapidly and with incredible regularity, the LGM-1 has a rotation period of 1.3 seconds. Strong radio signals are emitted along the axis of the magnetic field and because this is inclined to the axis of rotation, the radio beam points in the direction of Earth once each rotation, causing it to pulse like a beam of light from a lighthouse.

Artist conception of a pulsar with its magnetic field lines and particle jets

Pulsar: a rapidly rotating neutron star with a strong magnetic field

During an interview with a reporter from the The Guardian she was asked what the new stars were called. Burnell said she had been too busy to think about it. The reporter suggested an abbreviation of pulsatiing radio star, and that was agreed.

During the post lecture questions Burnell was asked by one of the school children in the audience about being overlooked for the Nobel Prize. She has obviously fielded this question may times and her stance is well known; research supervisors take the flak if the project flops and the credit if it succeeds, no matter how well, she explained. In those days, students were regarded as ‘support’, the ‘labourers’ poring for hours over paper charts, whereas the supervisors initiate and direct the research and as such deserve the credit. She is clearly not bitter, and has received many other accolades and honours as ample compensation. She claims that by not getting the Nobel Prize, she is in good company. She is right, take a look at the achievements of Cecilia Payne-Gaposchkin (composition of the stars) and Henrietta Leavitt (Cepheid period/luminosity), both worthy candidates.

January Meteors.

The main meteor activity this month around the 3rd/4th of January with the Quadrantids peaking in the early hours of the 4th Jan. Graves decided to go off line between 09:00 and 15:00 on the 3rd Jan. ( see red block on hourly plot).

The average hourly rate during the month was 2.2, with an average daily rate of 52.3. The variations during the month are due to the combinations of minor showers during the month, these are listed in table below.

I omitted the total count for 2017 in my new year post, this was 16,727with an average daily count of 46. It will be interesting to see what Andy’s magnetic collector picks up over the year.

 

Radiant Duration Maximum
Zeta Aurigids December 11-January 21 Dec. 31/Jan. 1
January Boötids January 9-18 Jan. 16-18
Delta Cancrids (DCA) December 14-February 14 Jan. 17
Canids January 13-30 Jan. 24/25
Eta Carinids January 14-27 Jan. 21/22
Eta Craterids January 11-22 Jan. 16/17
January Draconids January 10-24 Jan. 13-16
Rho Geminids December 28-January 28 Jan. 8/9
Alpha Hydrids January 15-30 Jan. 20/21
Alpha Leonids January 13-February 13 Jan. 24-31
Gamma Velids January 1-17 Jan. 5-8

 

Happy New Year from BASMO

New year celebrations caught by the all sky camera.

Below are the daily and hourly meteor counts for December, the peaks for the Geminids and Ursids are clearly shown. Unfortunately Graves went off line between 20:00 on 13/12/17 and 08:00 on 14/12/17. The increase in activity on 31st is beginning of Quadrantids, which will be peaking on the 3/4 Jan.

Here is a comparison with December 2016, Graves went off line last December for most of the 29th Dec.


This final plot shows the daily meteor activity throughout 2017, the major showers are marked, for more information on meteor showers go to http://meteorshowersonline.com/

Happy New Year

Pete Hill