Six years of working with amateur astronomers – an ongoing success story

By: Dirk Froebrich, PI of the HOYS Project

This article was originally published in Spanish in the magazine Astronomia.

Since starting my PhD at the Thuringian State Observatory, I have enjoyed public outreach. It started with giving tours at the 2m Schmidt telescope and talks at open days. Later on, I worked at the Dublin Institute for Advanced studies. This gave me the opportunity to chat to people, including amateur astronomers, during the open evenings at Dunsink Observatory. While working at the University of Kent, I have given numerous talks to amateur societies. What has struck me in all the conversations I had with amateurs at these opportunities is the enthusiasm they have for the observing and their desire to make actual contributions to research projects with their work.

My own research interests have focused on star formation research since the start of my career. However, I am not one of those people who will work for years on every little last detail of a specific aspect. That meant I have worked on a large number of different fields over the years. This included the youngest protostars, the structure and properties of molecular clouds, clusters of stars, jets and outflows from young stars and accretion outbursts. Thinking about how to study the latter, has set me on the path of the largest, most complex and most satisfying of my research projects.

Forming young stars grow by accreting mass. This process determines their brightness, final mass and rotation rate. Outbursts occur on young stars due to changing mass accretion rates. The resulting brightness changes range from a few percent to factors of a hundred for the most extreme, so called FU Orionis outbursts. They also occur on all sorts of timescales ranging from a few minutes for so-called flickering to hundreds of years for the large bursts. So the question was: How do we design an observational program to investigate all these?

It became clear quickly: We need to observe objects at a high cadence – once a day – to capture short-term variations. We need to observe objects over a long time to capture long-term changes. We need to observe as many stars as possible to maximise the chances of finding rare events. We need to observe the objects at multiple wavelengths to discriminate the outbursts from other form of variability. The obvious answer to all these questions is to observe young clusters of stars, each day in a number of filters over many years.

Doing this kind of survey by applying for professional time is virtually impossible. Building our own observatory at the University has helped, but given the UK weather, this is still far from ideal. However, we knew that there are many enthusiastic amateurs out there. They have suitable equipment at geographically distinct locations to enable us to perform the observations we needed. This was when the idea of the Hunting Outbursting Young Stars (HOYS) Citizen Science project was born. We selected a number of photogenic nearby young clusters (e.g. Orion Nebula, Pelican Nebula, Elephant Trunk Nebula, Christmas Tree Cluster), since these are objects amateurs take images of anyway. Now everything we had to do was to collect and analyse the images.

The data analysis is a technical, computational problem that simply takes time, effort and resources to solve. Finding amateurs to send us their images and convince them to keep imaging our target regions as often as possible over many years is a completely different kettle of fish. We started locally with amateurs in Kent and organised an imaging workshop for them. This gave us a handful of participants with whom we could test our ideas and data analysis procedures. Slowly, by word of mouth and the help of some of the amateurs, we grew to about two dozen participants. However, this was still far below the numbers we need to achieve our science goals.

Subsequently we convinced the University to give us some travel funds to tour UK amateur societies to advertise and grow the project. This resulted in more than 10.000 miles of travelling, over 45 talks, including several at amateur conferences, and an observing campaign coordinated via the AAVSO. This has increased the project to about 70 participant who have actively contributed data. This has allowed us to make significant progress. We are now obtaining about 25 images each day, roughly 20% of the set goal of getting one image per filter per target per day.

Going forward, we have to solve a number of problems. In particular, how we keep participants motivated to continue contributing data. We have had several very enthusiastic participants that suddenly stopped engaging. It seems to be important to have well connected, key people in the project. These can help us to keep the interest in the project up on a local level or in pre-existing groups. A prime example is the Spanish group of Supernova Observers. Sixteen of their members have now contributed vital data for our science and many of them continue to do so on a regular basis.

Since last year, we involve some of the amateurs in the running of HOYS. We disseminate our science results to the participants and beyond via our website and social media. The wealth of data we already have is tremendous. So are the possibilities for scientific exploitation. We set out to investigate outbursts from young stars. However, we also can study eclipsing binaries, occultation of stars by material in their accretion disk, the rotation of stars and many other topics. We have also started to put together educational material that will allow everyone to analyse our data on his or her own.

Hence, if you are looking to contribute to our research, either by providing observations data or by analysing light curves from stars, consider becoming a HOYS participant. Even a few minutes of observing can provide vital scientific data while you indulge in your hobby. If you know others who might be interested, please let them know about the project. Share, retweet our posts and feed back to us any ideas you have in order for us to continue to improve and grow our work with amateurs across the globe.

Figure Caption: HOYS image of the Pelican Nebula star forming region in Cygnus. The inset shows six weeks of the light curve of the young star V1490Cyg. It shows semi-periodic dips in brightness due to occultations by it’s warped inner accretion disk. This warp is most likely caused by a protoplanet.