A Supernova Discoverer's Diary 24th Feb 1987

...Entry for Tuesday 24th. February 1987. Observed in the evening.  Suspected a super nova in the large magellanic cloud near 30 Doradus!  Phoned  Richard and left a note with his mother.  The object seemed to brighten but I am very sceptical.  Could not confirm existence of the object in Norton's Star Atlas, Australis or the SAOC.  It was not on my sketch of the large magellanic cloud in the Webb Society quarterly Journal.  I could see it easily with the naked eye!

Diary entry for February the 24th 1987.

Rose slightly late and missed the old lady, but got the express taxi all the way to Rimuka.  I had asked Farai yesterday to set me for chlorine again using K Mn O  but the apparatus was conspicuous by its absence.  He sauntered in  and  I had to wait while he set it up.  Did chlorine with 4A then did a practical on flowers with 3A4 and 3A6.  In the afternoon I got a taxi to town with Diane.  She was getting a little disillusioned and thought she would not last for three years.  The form fours were skiving off afternoon lessons and Ramesh was getting pissed off.  Got a letter from Dad, went to the Ranch Motel and got a lift off the old lady who was coming home.  Had a siesta but was blasted out of my sleep by the telephone.  It was Jim Buckley who wanted details of 4A's timetable.  He wanted to give them extra lessons in English.  Shortly afterwards Richard phoned saying he had got my message.  He said his 20 in telescope was ready and that he had used it to observe the comet.  Arvin phoned after dinner and put me through to Gerard.  We agreed I should stay with Arvin tomorrow afternoon and that Gerard can pick me up around 2.30pm after his cricket match.  We can then have a meal and he can drop me off in the evening.  Observed in the evening.  Suspected a supernova in the large magellanic cloud near 30 Doradus.  Phoned  Richard and left a note with his mother.  The object seemed to brighten but I am very sceptical.  Could not confirm existence of the object in Norton's Star Atlas, Australis or the SAOC.  It was not on my sketch of the large magellanic cloud in the Webb Society quarterly Journal.  I could see it easily with the naked eye.


February the 24th 1987 - A day I shall never forget.

Tuesday 24th 1987 was just another ordinary day at school.  I went in first thing in the morning and carried out a gas preparation with my form fours - chlorine, using potassium permanganate.  Later I took two form three classes and carried out a practical on floral structure, probably using hibiscus flowers from the hedges marking the boundary to the school grounds.  At the end of the day I left the township with a colleague in a taxi, and after lunch had my usual afternoon siesta.  After dark I went out to my observing site to make some routine observations of variable stars.  This location was only a few yards from my room, but was well shielded from lights by numerous trees and bushes.  On the way I noticed that the 30 Doradus nebula in the large magellanic cloud seemed unusually conspicuous.  I set about my variable star observations, recording estimates of Eta Gem, R Dor, V Hor, I Car, and R Pic.  I then remembered what I thought earlier about the 30 Doradus nebula.  Maybe I should better check it out with my binoculars.  I was astounded by what I saw.  Just south preceding the nebula was a conspicuous fourth magnitudes star, which I was certain was not there before.  I was convinced that I had spotted a supernova.  I returned to my room and using my atlases and catalogues I prepared a rough sequence for the object so I could make an estimate.  My first estimate was recorded at 19.16 universal time at magnitude 4.6.  When I first saw it  I suspected it was slightly fainter.  To confirm the object I took several photographs with an undriven camera.

A few years earlier I was shown a photograph of the large magellanic cloud in hydrogen H alpha by Ken Elliot of the Astronomy Department of Manchester University.  It was full of supernova remnants and stellar wind bubbles.  I was convinced that supernova had exploded in the large magellanic cloud quite often and that should one appear then it would be a conspicuous naked eye object, possibly reaching first magnitude.  By this time I had been living in Zimbabwe for several years and had familiarised myself with the visual appearance of the large magellanic cloud as part of my Milky Way project.  Any supernova appearing in the large magellanic cloud would be spotted immediately.  As the object was only fourth magnitude when I found it, I realised it was probably still brightlening, so I decided to watch it over the course of the night to see if it changed.  Three more observations were made, and each one was brighter than the previous one, at 19.56 UT  4.4 magnitude, 21.08 UT  4.1 magnitude, and 22.47 UT 4.0 magnitude.  This seemed to confirm my suspicions that I had found a supernova.  By the time I finished observing I had recorded further estimates of TW Hor, alpha Aps, and V. 744 Cenand and the "object" was quite obvious with the naked eye.  Walking back to my room I thought that the sight of the supernova in the large magellanic cloud reminded me of photographs of supernova that I had seen in other galaxies.

During the observing session I took a short break.  I had to inform the outside world and the easiest way was to contact my friend Richard Fleet in Salisbury who had access to a telex machine.  Telephone links with the outside world still had to go through the operator, so I thought it would be easier if I called Richard.  He had in fact phoned me earlier in the day, saying his 20inch telescope was now ready and that he had used it to observe Halley's comet.  I phoned Richard but his mother took the call.  It was raining in Salisbury and Richard had already gone to bed.  His mother didn't want to go over to his cottage as she didn't want to get wet! The following day after school I visited the local libraries and checked out photographs of the large magellanic cloud in the astronomy books.  No object of fourth magnitude could be seen near 30 Doradus.  My excitement began to rise further.

On February the 26th I was in my laboratory teaching a class when a girl arrived at the door with a message.  Children interrupting classes with messages was a very irritating problem and it was not the first time that I had queues of children at the door with petty messages to give to the class.  Sometimes I hardly got any work done and then I would fall behind.  I resolved that the problem would have to be raised at a staff meeting.  I nearly told the girl to clear off when she told me that I had a phone call.  The phone was in the staff room about a hundred yards away so I dashed over in case the caller decided to hang up.  It was Richard.  He confirmed a supernova in the large magellanic cloud, and said there had also been discoveries in Chile and New Zealand.  By this time I was elated.  Who was the first to see it?  At this point in time we didn't know.  Unfortunately Richard's mother didn't tell him of my phone call on the night of discovery.  He only heard about it over the BBC world service.  His mother then told him "Oh Colin phoned on Tuesday night, something about a supernova in the large magellanic cloud"!

That night I observed it again and to my surprise it was only fourth magnitude.  In fact it had faded down to 4.2 magnitude when I was expecting it to have been brighter than magnitude 2.  It was obvious it was not behaving as a typical supernova.  I also made a colour estimates, at one degree on the Hagen scale, indicating it was slightly off-white.  The following night, February the 27th, it had faded to 4.4 magnitude.  What on Earth was it doing?(sic).  On February 28th, it was 4.5 magnitude.  I was going to England on March 1st, to attend an interview with the British Council scheduled for March 3rd.  I stayed with Richard that weekend and he dropped me off at the airports on the evening of March 1st  in Salisbury.  On the way we stopped on the dark road and I made one further observation and it was still at 4.5 magnitude.  Earlier Richard had contacted the Zimbabwe Heralded and an article appeared which outlined my role in the discovery of the supernova.

I stayed in England for two months.  The interview that I had was successful and resulted in my move to Botswana a few months later.  Meanwhile the supernova brightened.  When I returned to Zimbabwe at the beginning of May it was already third magnitude and very red.  It continued to brighten and on May 16th I recorded it at its brightest at 2.6 magnitude, after which it began a slow decline.  I took several photographs of the supernova through Richard's 20 inch telescope which clearly showed the colour change before and after my stay in England.  My earlier photographs were processed in London, and with the aid of Peter Hingley in the RAS library, they were shown on Patrick Moore's Sky at Night programme on BBC television.

I continued to monitor the supernova right through 1987 and into 1988, and I finally said goodbye to it on January 1st 1989, when I estimated it at 11.1 magnitude through Richard's 20 inch telescope during a short return trip to Zimbabwe.

I am continuing my search for supernovae and my variable star observations continue, weather and light pollution permitting!!


by Colin Henshaw, Gatley, September 1999.

#Supernova #Discovery

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