Wednesday, November 19, 2025

A Personal tribute to Heather Couper

I wish to pay a personal tribute to the astronomer, broadcaster and writer Dr Heather Couper (2/6/1949 - 19/02/2020) who died five years ago at the relatively young age of 70. She was a great ambassador for astronomy and somebody who took an interest in young people and encouraged them to be astronomers. This was true of myself and, by way of thanks, I want to write down how she influenced me into trying to become a professional astronomer.

When I was at Haileybury College between 1975 and 1980 I gained an interest in astronomy by accident rather than by design. At the school we had a number of different societies to which we could belong and one time, when I was obviously at a bit of a loss as to which one I should join, someone suggested the Astronomical Society. I knew very little about astronomy at that time. I was very science orientated (particularly in physics) but I knew very little about the stars. We were very lucky in those days because the school had an observatory which was equipped with a 4.5 inch refractor (probably a Cooke telescope). This was a splendid old brass instrument, mounted on a pier and contained within a brick building. Here is a picture of me standing outside it when I returned to visit the school in 2000:-

By then it had begun to look as though it had been abandoned. Looking on Google Maps today, the observatory is still there and the dome is in intact but it sits forlornly at the corner of a machinery yard. It makes me wonder if the telescope is still inside.

I was assisted in my learning about astronomy by one of the society members - a Scottish lad who was a five years my senior and who knew how to work the telescope. This was Barry Gardiner who later went on to be an MP and a junior minister in Tony Blair's government. I can still recall him saying to me that I needed to understand about Right Ascension and Declination and showing me a copy of Norton's Star Atlas. This book was probably the prime atlas for amateur astronomers at that time and in 1980, when I won the Powell-Davis Art Prize at school, I asked to be given a copy as a reward (rather than an art book)! So armed with this book and a knowledge of how to use the school telescope I began to explore the skies and after a while I was hooked (I can still remember my first views of objects like Orion Nebula and the impact it had on me).

So, as I progressed through school I remained in the Astronomical Society and as I entered my A-level years I became its secretary. This meant organising meetings of the society and in the summer of 1980 I arranged for an excursion to the Royal Greenwich Observatory in London. Of course I had a lot of help in this from my physics teacher and mentor Ian R Williams (or Doc Williams as he was known). Ian was a superb teacher and very inspiring as he had himself done a PhD in low-temperature physics. You have to understand at this time I was on course to study architecture at Manchester University. I had taken A levels in Physics, Chemistry and Art (yes, I know, an odd combination) and had an offer of a place at Manchester. This had been my direction for a number of years, mainly because I come a family of architects and it seemed like a good profession to go into.

So the day came for a group of us from school and Doc Williams to head into London to the Royal Observatory at Greenwich. We travelled by train, tube and then by boat up river from the center, which was very exciting. In the morning we were to go to the Planetarium and to be treated to a show by one of the lecturers. This is when I met Heather Couper for the first time (she had been appointed senior lecturer there in 1977) and it was Heather who gave us the an excellent planetarium show that entertained us from start to finish. There was always something sparkly about Heather's talks and she always liked to introduce something slightly risqué and in this case it was alluding to how the constellation of Virgo was seen lying low above the horizon at that time of the season. 

At the end of the talk Heather mentioned that she was organising an event for young budding astronomers later in the year and said that if we were interested we could put our names down for it. At the time I didn't think much more about it. We headed off to look round the observatory buildings and then down to the National Maritime Museum (the girls in our group disappeared off shopping in Greenwich!). However, later on when I was back at school I began to feel that I was more interested in astronomy and physics than I was in architecture and one day in dining hall I had this epiphany moment! I was going to do it, I was going to become an astronomer! For the first time in my life I realised what I really wanted to do with my life.

It was quite a turn around and there were a few obstacles to overcome, not least that I needed an A-level in mathematics. I didn't really know how to go about this. My maths skills had been somewhat mediocre up till that point but I had done very well in physics and I knew that I must have it in me somewhere. I went to the careers advisor who turned out to be Mr Bentley who had, by coincidence, been my maths teacher right up until O-level (I famously got 5 out of 95 for one of his maths tests). To his credit, he didn't try to dissuade me and I am grateful to him for not doing this. He laid out a plan for me and said that I would need to go to a college in London (a "crammer" as they were called then) and see if I could get an A-level in mathematics in a year. So this is what I did and went to Davies's College in Southampton Row and a year later I had a grade A maths A-level to add to my tally.

In the mean time I recalled what Heather had said about her event for budding astronomers and I wrote her a long letter telling her about my desire to change career and to come to her one-day meeting. I am forever grateful that she took the time to write back to me and to add me to the list of participants. Later in the year I found my way back into London and attended the day where a number of current astronomers talked about how they had got into this line of work. One of them was Dr Jim Emerson (now emeritus professor) at Queen Mary College, London where eventually I went to study. I can still recall how he said in his talk that it was determination and not necessarily brains that got you where you wanted to be in work.

So, after reapplying to study astronomy at a number of universities, I ended up at Queen Mary College doing a BSc in astrophysics. I continued to see Heather from time to time socially (as she was friends with another student on my course) and she was always encouraging to me and interested in my progress. I was so pleased when she and Nigel Henbest came to my 21st birthday party - it was a real honour to have her there (but then parties were Heather's thing!). My career in astronomy carried on for a number of years until 1992. I left QMC with first class honours and a very good background in mathematics (I had even managed to pass the General Relativity course in the mathematics department). It all went to my head and I tried Part III of the Mathematical Tripos at Cambridge (which had a lot of theory of astrophysics in it) but failed. I picked myself up and dusted myself down and went to do a PhD at Durham University which I finally finished in 1990. My subject was cosmology and the large-scale structure of the universe. I was awarded my PhD and carried on for a couple of years doing research but eventually I found myself in the real world with what my mother would call a proper job in business.

However, my interests in astronomy continue and I will forever be grateful to Heather for being there at the right moment and providing me with the idea that I really could do this and get into the professional world of astronomy. We need more people like her and the other teachers that helped me along my way to inspire and to encourage.


Heather Couper and Nigel Henbest in their garden in Greenwich in about 1983.

All text and images © Duncan Hale-Sutton 2025 

 

Tuesday, November 11, 2025

Comet C/2025 A6 (Lemmon)

We have been fortunate to have several comets grace our skies recently and the brightest of these has been comet Lemmon. This comet was discovered by David Fuls on the 3rd January 2025 during a survey at Mount Lemmon Observatory. During the intervening months it has significantly brightened and around the end of the October it reached its maximum luminosity of about 4th magnitude. On October 25th I was fortunate enough to get a good view of the comet when we had some clear skies in the early evening. At 19:41 UT I took this wide-field view:-

 

The comet has been marked on the image with green lines (the image can be better viewed by clicking on it). It sits in the constellation of Serpens (Caput - i.e. the head) and below the distinctive crown of the constellation of Corona Borealis. The field of view this image is approximately 64x46 degrees. I used a Sony RX100 camera with an exposure of 10s at f/1.8 (ISO 1600). I took another image with the same camera and pointing in the same direction but used a focal length of 20mm rather than 10mm:-

 

This was again a 10s exposure at ISO1600 but this time at f/3.5. The comet has again been marked. Looking closely at this image you can see that the comet tail extends quite a long way up towards the crown of Corona Borealis (some 12 degrees). The field of view of this image is approximately 36x25 degrees.

Finally, I wanted to look at how the comet's position compared with ephemeris predictions. For this I took a chart produced by Nick James at the BAA and overlaid it on my first image that I took:-

 

It was difficult getting the orientation and scaling correct but by making sure that the stars near the comet overlap reasonably well, you can see that the comet does indeed sit on the predicted path. As the observation time was 19:41 UT on the 25th which is 0.820 of the day, you can see that the comet is about the right distance along the track towards the 26th tick mark from the 25th tick mark (taking that the tick marks are for midnight UT).

The comet is now beginning to fade and passed perihelion on the 7th November. 

All text and images © Duncan Hale-Sutton 2025 


 

Wednesday, October 8, 2025

Variable star observations in September 2025

I was able to make some further variable star observations in September. Firstly, on the 13th where the moon was one day before last quarter, I had a go at three stars with my 10x50 binoculars. Twilight ended at about 20:30 UT and the moon rose at 20:27. The skies were clear but the sky transparency was average. Here are my results:-

TX Dra, 20.59 UT, chart 106.04, K(4)V(3)N, mag. 7.4
AH Dra, 21.14 UT, chart 106.04, 2(2)V(3)6, mag 7.5
CH Cyg, 22.03 UT, chart 089.04, F(1)V(6)H, mag 8.6 
 
CH Cygni has been fading quite a bit recently. It is now approaching 9th magnitude, which makes it difficult to measure in smaller aperture binoculars. It may not get any fainter than 9.5.
 
On the 30th September the moon was one day after last quarter and wouldn't set until about 22:03. Twilight ended at 19:45 UT. The skies were clear apart from some cloud in the south west. The sky transparency was again average. I observed TX and AH Draconis again. I also had a go at CH Cygni but I gave up as it was too faint. Here are my results:-
 
TX Dra, 22.22 UT, chart 106.04, K(3)V(4)N, mag. 7.3
AH Dra, 22.34 UT, chart 106.04, 2(2)V(3)6, mag 7.5
 
All my results are in very good agreement with other observers from the BAA.
 
All text and images © Duncan Hale-Sutton 2025 

Thursday, September 11, 2025

Some observations over the summer

It has been a couple of months since I last added anything to this blog. The summer season of twlight filled nights is coming to an end now and I am looking forward to more dark observing sessions in the coming months.

There have been a couple of things to note. On the night of the 12th/13th August I spent half an hour or so looking out for Perseid meteors. It was three days after full moon and so this made the sky pretty bright. However, I did spot five meteors, two of which were significant and left long trails.

Two weeks ago, on the 25th August, I dug out my 10x50 binoculars and did a couple of variable star observations.  This was the last time we had the moon out of the way and on this night it was two days after new moon. Astronomical twilight ended at 21.20 UT. The skies were clear and we had good sky transparency. Using BAA chart 217.02 I made observations of Z and RY UMa:-

Z UMa, 21:37 UT, chart 217.02, D(3)V(2)E, mag. 8.2 
RY UMa, 21:45 UT, chart 217.02, =4,  mag. 7.7
 
Z is beginning to fade rapidly since its peak in May.
 
Finally, on Sunday, the 7th September, there was a total eclipse of the moon. This was always going to be a difficult eclipse to see as the moon wouldn't rise until 18.31 UT and by then a lot of the full eclipse had already happened. As it turned out there was a bank of cloud from our observing location however we did see part of the umbra covering the moon as it rose through a gap in our hedges! This was somewhere between 18:52 and 19:56 UT (19:52 and 20:56 BST). I did try to take a photograph but by the time I got a scope set up, the umbral part of the eclipse was over.
 
All text and images © Duncan Hale-Sutton 2025 

Tuesday, July 1, 2025

Start of the NLC season

Just over a week ago, on the 23rd June 2025, we had our first display of Noctilucent Clouds (NLC) this summer season. I have written about how these high altitude clouds are formed in a previous post. Here is what I saw at just after 11pm BST (22:04 UT):-

This image was taken with a Sony RX100 (1/3s, f/1.8, ISO 1600) and has been cropped so that the cloud features can be seen more clearly (click on the image to obtain the full size version). To the right, near the chimney pot, the head of the constellation of Perseus is rising. The maximum elevation of the clouds is about 16 degrees above the horizon and the display stretches about 49 degrees in azimuth across the sky. I thought that there were three types of cloud present here - type I which is a type of veil, type II which are lines or streaks and type III which appears as a fine herring-bone pattern (this can be seen most clearly to the left of the picture just above the old TV aerial).

It is interesting to me that I have seen these clouds on exactly the same date on 23rd June last year (2024) and the 23rd June 2021. It makes me wonder if this may be the time when these clouds can first be seen in the season. 

A few days later on the 28th June 2025 I saw some more:-

This was not such a good photograph as it was hand held (Sony RX100, 1/2s, f/1.8, ISO 400) but it does show the type III herring-bone pattern at low elevation (much lower than before, the maximum elevation was only about 7 degrees). This was taken a bit later at 22:37 UT.

What is an odd coincidence is that I saw NLC's on the 28th June last year too. Next year I must see if this pattern in dates of appearance repeats again (provided we get some clear weather).

All text and images © Duncan Hale-Sutton 2025 


Monday, June 23, 2025

Orientating an image - a better procedure

Previously, I described a way of orientating an image so that the edges of the frame are parallel to the North-South and East-West directions. In a lot of situations this perhaps does not need to be that accurate but in the case of binary stars where you are trying to determine the position angle (PA) of one star relative to another, then it does become a bit more of an issue. For example, I had been taking some measurements of the separation and PA of the binary star Xi Bootis, and I wondered if my method for orientating the image could be improved. After all, I was using Photoshop and a chart to determine the angle that a line between two field stars made with the horizontal side of the frame. This was potentially inaccurate because I had to place a cursor on where I thought the centre of the field stars were on the chart.

Let me now revisit the problem. Below is the image I took of the binary star after I had rotated it to what I thought was the correct orientation:-

 

As well as the two components of the binary star Xi Boo A and B you can faintly see two field stars in the image. To show this better and get an idea of the problem have a look at the diagram below:-

The field stars have been marked as 1 and 2 and there is a dashed line between them. I have also indicated a dashed line that travels due north from 1 until it meets the line drawn due east from 2. In the situation where the angular distance between field stars 1 and 2 is small (less than a degree or thereabouts) then the right angle triangle approximately lies on a flat plane. Let the angular separation between the two field stars be S. This forms the hypotenuse of the right angled triangle. The vertical dashed line forms the adjacent side to the angle θ marked. This side represents a separation which is the difference in the declinations of the two stars. Let this be δ² - δ¹. It follows from basic trigonometry that the angle θ is to a good approximation θ = arccos (δ² - δ¹ / S).

Now this is all very well but we have to determine the equatorial coordinates of the field stars. If you view the page on the BAA website where observations of Xi Boo have been made you will see that, not only is there a link to In-The-Sky.org, but also a link to the SIMBAD astronomical database for this object. This is a very cool page! If you look near the top of the page there is a 'submit query' button and on the same line just before it there is a field where you can adjust the radius of the search. Changing this radius to 12 arc minutes gives a wider view of the locality round Xi Boo and on the left an image with circled objects. Each of these circled objects (in different colours) relates to a line in the table to the left. If you hover over an object in the image it highlights it in the table (very neat).

This enables us to determine what our field stars are. It turns out that star 1 has a designation of V* EO Boo and star 2 has a designation of BD+19 2872 (they have V magnitudes of 8.43 and 9.06, respectively). Furthermore the table lists the epoch 2000 coordinates of these two stars as RA 14 51 42.2211380760, Dec. +19 05 21.217940052 and RA 14 51 38.0435867520, Dec. +19 10 23.589683616, respectively. I am amazed that they are quoting the accuracy of the positions to 9 decimal places in seconds of arc! Using my routine to calculate the separation of these two stars I find that S = 0.085586862 degrees. Further, δ² - δ¹ can be determined from the stored variables of the program and this corresponds to Z-X. I find that δ² - δ¹ = 0.083992154. Hence  θ = arccos (δ² - δ¹ / S) = 11.07775584 degrees.

If I now compare this value of θ with some measurements of this angle from my image above using Photoshop I get a value of 11.3 degrees, as best as I can determine, so I think I did a pretty good job in orientating my image!

All text and images © Duncan Hale-Sutton 2025
 

Friday, June 20, 2025

Z Ursae Majoris beginning to fade

Just over a week ago, one day after full moon on the 12th June 2025, we had some more clear weather which enabled me to get another view of the variable star Z Ursae Majoris. The twilight at about 22:00 UT (23:00 BST) is now very bright but Z remains pretty much near its peak and so determination of its magnitude is not too much of a problem. Using 10x50 binoculars my estimate was:-

Z UMa, 22:23 UT, chart 217.02, A(1)V(1)B, mag. 6.8

The star is now beginning to fade. At the present time (20th June 2025) it is about 7th magnitude. It looks like the peak in brightness is going to be sharp as I predicted but it may yet brighten again or slow down its fade. We shall see!

All text and images © Duncan Hale-Sutton 2025