Dunsink Lane, Dublin 15, D15 XR2R

Meteors 2020: Interview with Mike Foylan

From our regular blogger Qi Qi Kennedy, Masters student at UCD

Continuing on the review of the meteors project over the last few years at DIAS Dunsink Observatory, next on my list was citizen scientist Mike Foylan, member of the British Astronomical Association, NEMETODE Network, Kingsland Observatory. Mike also runs his own observatory, called Cherryvalley Observatory in County Meath, Ireland and is a member of the NEMETODE meteor network. When I spoke to Mike I discovered his passion for astronomy, Cherryvalley Observatory and his involvement over the many years with DIAS Dunsink Observatory.

Mike first became interested in astronomy when he was five years old. He lived in a small town in County Meath with very little light pollution and, when on a walk with his older sister, he looked up at the stars and thought, “Wow! This is amazing!” From then on he wanted to find out more, and later to question and understand the science of the night sky. 

Cherryvalley Observatory

A lot of Mike’s astronomy knowledge was gained through reading books and journals from his local library, as astronomy was not taught in schools at that stage. He thinks adding astronomy to the curriculum is a great addition to the educational system here in Ireland. Mike started his hobby in astronomy making quantitative measurements of asteroids and stars and so learning about photometry and astrometry.

Mike’s Meteor Camera System at Cherryvalley Observatory, showing also the sky coverage over Ireland and the UK, and some examples of the spectacular meteors detected over the years.

Mike established Cherryvalley Observatory in County Meath in 2010. He submitted his first observations of asteroids in 2011, including measurements and their positions, to the Minor Planet Center. Mike says, “your first submission is always the most scary because you’re submitting your results, your data, to professionals”. After this submission Mike was awarded his observatory code (I83) and full recognition. Cherryvalley observatory has a number of authored and co-authored peer reviewed papers published in the Minor Planet Bulletin, Journal of the British Astronomical Association and the WGN, the Journal of the International Meteor Organisation (IMO) in collaboration with colleagues and friends from the UK, USA, Italy and Ireland. Mike finds it fascinating, interesting, enlightening and fun to do astronomy, and to share his knowledge freely with others.

In his observatory Mike installed a 200mm (8-inch) diameter Schmidt-Cassegrain Telescope (SCT), with a corrector lens attached to give a wider field of view. He says, “A wide field of view is much better because then you can get many comparison stars in the same field of view as the object you are observing”. Mike has a cooled CCD camera dedicated to astronomical imaging and measurements. He also has a Celestron CG5 mount, modified to be computer controlled. Mike says, “You don’t have to spend a lot of money, you can get pretty good stuff secondhand, and you can build your observatory with this.”

Lightcurve of minor planet 1888 Zu Chong-Zhi (Picture Credit: Mike Foylan, Kevin Stephen Smith & Basil Rowe)
Cherryvalley Observatory carries out photometric studies (measuring light properties) of minor planets (asteroids) with friends and colleagues based in Ireland, UK, US and Italy. This is combined work of a “Lightcurve” of minor planet 1888 Zu Chong-Zhi, with almost 600 data points taken from three different observatories over ten nights, and which shows its rotation period to be just over 11 hours. The shape of the lightcurve also reveals the approximate shape of the asteroid, in this case somewhat like a potato! The asteroid was observed from Cherryvalley Observatory (I83), Dunboyne Castle Observatory (Z67), both observatories based in Co. Meath and RMS Observatory (W25), based in Cincinnati, Ohio, USA. Minor planet 1888 Zu Chong-Zhi is a main-belt asteroid (resides between the orbits of Mars and Jupiter). Its orbital period is just over four years with an estimated diameter of 11.6 km. (Picture Credit: Mike Foylan, Kevin Stephen Smith & Basil Rowe).

Observing Asteroids

On a typical observing run, Mike looks for asteroids that are approaching opposition. This means that the Sun, Earth and the asteroid are almost in a line, and the asteroid is at its brightest. Mike plans the asteroids he is going to target: he finds out what time they are rising at, their location in the sky and how long he can track them across the sky. Following this he sets up his equipment and programmes his telescope system to look at specific asteroids and record the images and make the measurements required. This can take up to a few weeks depending on the asteroid. Mike uses various software packages to process the data taken from these observations. For data acquisition (capturing the images and tracking the sky) he uses “The Sky Six” software and “CCDSoft”. For processing the images and making measurements he uses Minor Planet Observer Canopus.  Mike says “the hardest part is actually processing all the data”, something all astronomers, professional and amateur, can relate to!

Involvement with DIAS Dunsink Observatory

Mike’s involvement with DIAS Dunsink Observatory began at a Public Open Night quite a few years ago. He remembers being really impressed by the historic Grubb Telescope, and the historical significance of the observatory for Ireland. He enjoyed meeting other people with a similar interest in astronomy, and through this he got to know the Citizen Science volunteering group at DIAS Dunsink Observatory. He was delighted then to be asked to give a talk on his work. This was Mike’s first time to give a detailed talk to the general public about the astronomy work he carries out, and he enjoyed it immensely. Mike learned a lot from being around Dunsink Observatory discussing with the Citizen Science volunteering group there, and this gave him huge encouragement to carry on developing his skills further. He says that he learned a lot about presenting his knowledge in a way suitable to different audiences over the years.

Lightning Sprites seen from Cherryvalley Observatory (Mike Foylan)
As well as recording meteor events the camera system records (on very rare occasions) electric atmospheric phenomena known as “Lightning Sprites”. These occur above intense thunderstorms, and reach heights of 80 to 90 km, the same altitude that meteors start to burn up. Lightning Sprites are very brief in nature, usually only captured in one to two video frames. (Picture Credit: Mike Foylan)


Mike first got involved with meteor cameras in 2007, after meeting Apostolos (Tolis) Christou, astronomer at Armagh Observatory and expert in meteor observing and Solar System objects. He gave Mike a lot of advice about starting up, equipment and software. Since then Michael O’Connell, Mike and others got together to form a network called NEMETODE. This network has lots of members in Ireland, the UK, Northern Ireland, and the North of France. Mike says, “It’s great to have that kind of group of people because in the early days we were starting out from scratch.  It’s great to meet people with the same interests, and to teach, learn and work together to grow a really good network”. Mike gives some public talks on meteors, including in the national primary school system and has carried out some astronomy-related experiments with the teachers and pupils. Mike says, “It’s been an interesting road, getting what I do and my interests across to other people. It’s been a good experience overall.”

February 2017: Mike Foylan attended Galway Astronomy Festival (hosted by Galway Astronomy Club) and presented an updated version of the NEMETODE Poster Paper he first presented back in 2015. (Picture Credit: Ann Dunne of Astronomy Ireland.)

Citizen Science

Mike says Citizen Science is really important, including having Public Open Nights and outreach projects in schools, colleges and outside. It brings living, active science to people of all ages. He says, “I’ve seen families on Public Open Nights at Dunsink and children are often asking the best questions”.  He says it’s a really great opportunity to talk to people from the Dublin Institute for Advanced Studies (DIAS) and associated people like him about the work they do. Mike tries to attend the Irish National Astronomy Meeting as often as possible. He says, “all these opportunities are great as part of the Citizen Science Outreach Programmes. It just gives the opportunity for everybody to get involved”. Mike says that visiting places such as DIAS Dunsink Observatory, as well as talking to researchers from DIAS and the amateur astronomy community, instils a sense of excitement and thirst for knowledge. He says that the opportunity for young people to come to places like Dunsink Observatory is really important, and can inspire the next generation to take up a career in science.

When observing asteroids over many hours in the same area of sky it’s also possible to find Variable Stars, for which the brightness changes over time.  Some stars are intrinsically variable, whereas others appear to vary because they are in eclipsing binary systems, where one star periodically blocks light from its companion, and vice versa. Cherryvalley Observatory working with friends in Italy has discovered a number of new Eclipsing Binary Star Systems. In this discovery example from 2015 a new close contact EW (or W UMa) type of eclipsing binary system (two stars that are so close material is flowing between them, with short orbital periods typically measured in hours) was discovered in the constellation of Ophiuchus, the serpent-bearer. More info on the detection from the AAVSO website and journal article.
(Picture Credit: A. Marchini, F. Salvaggio, M. Foylan, R. Papini (Obs. Univ. Siena))