Spectroscopy – Interview with Olivier Thizy (Shelyak Instruments)

At Share Astronomy we are very interested in citizen science. In my opinion, one of the most influential people involved in promoting professional / amateur collaboration in astronomy is Olivier Thizy. Mr. Thizy is one of the co-owners of Shelyak Instruments headquartered in Revel, France. Shelyak Instruments produces a wide range of spectroscopy products (e.g., Lhires Lite, Lhires III, eShel, etc.) designed to promote scientific astronomy within the amateur community. Recently, I was fortunate enough to interview Mr. Thizy. The interview is included below:

You are a co-owner of Shelyak Instruments. How did you get started in spectroscopy and what motivated you to start a company that manufactures spectroscopes, spectrographs and related equipment for amateur astronomers?
When I started astronomy in a club in 1980, I loved watching for the stars at night and deep sky observing with a small refractor that my parents offered me at Christmas. But I quickly wanted to go beyond simply watching or imaging celestial objects and looked for scientific projects to conduct. I started with photometry first with jupiter moon mutual phenomena (I remember putting a motor on a SLR so the film was slowly moving while capturing the flux of a satellite as a trail; analyzing the trail later on gave indication on exact event timing). I then studied asteroids and their light curves providing interesting data on their shape. I started to be interested in spectroscopy in general in 2000.
In 2003, I participated in a professional/amateur symposium organized by the French research organization CNRS. It became obvious that amateurs did not have the proper equipment, lacking resolution to detail absorption line profiles in stellar spectra. François Cochard, co-owner of Shelyak Instruments, Christian Buil, Yvon Rieugné and I worked that year to design a high resolution spectrograph – Lhires. We industrialized the Lhires and made it available at cost as a one-time offer within the French AUDE non profit association whose goal is to promote science in astronomy. This one-time offer was so successful that François and I decided to start a company to continue to make the Lhires III available and promote spectroscopy among amateur astronomy. We then extended our product range including the first commercial echelle fiber fed spectrograph to astronomy.

Why is spectroscopy so suitable for collaboration between professional and amateur astronomers?
Spectroscopy transformed during the 20th century into astrophysics, revealing the nature of the stars, nebulae or galaxies. If you look at professional astronomer time requests on large telescopes, you will notice than more than 80% of the observing time is in spectroscopy. It is natural for amateur spectroscopists to help the professional community on some bright targets – I believe this is a new field for pro/am collaboration!

IAU (International Astronomical Union) Symposium 272 was held in Paris from July 19-23, 2010 and I believe you were in attendance. How did amateur astronomers contribute to the science that was highlighted at this conference (active OB stars)
AU Symposium 272 focused on active OB stars. OB stars are very luminous stars and more than a third of naked eye night sky stars are O or B type stars. That makes them very easy targets for amateur spectroscopists even with a small telescope. About 16% of the posters presented at this symposium had or could have had amateur contribution. A good example are Rigel and Deneb, supergiant active OB stars which eject material. Those ejections can be monitored in spectroscopy with emission lines of a specific profile called P Cygni. Using an off-the-shelf eShel spectrograph, Christian Buil recorded several spectra of those stars. As a professional astronomer said, "those spectra were well calibrated and very useful to complete our series of observations".

An excellent result was published during IAUS 272 on Wolf-Rayet 140 with several amateurs contributing to the 2009 periastron campaign.

Several posters included amateur contributions on Be stars. Those non supergiant B-type stars show (or have shown in the past) emission in their spectra. Some are very bright (gamma Cas, delta Sco, beta Lyrae – Shelyak!, …). About a hundred of the naked eye stars are Be stars. Still, despite their brightness, the process which ejects material from the star into a disk is unknown at this point of time. Some correlation with Non Radial Pulsations have been recently detected. Magnetism, strong stellar wind, fast rotation… several mechanisms could work together to make this happen and continuous observations are required to better understand those mechanisms. Spectroscopy from amateurs can provide key data for this understanding.

What are the ArasBeam web site and the BeSS database? How have you and Shelyak Instruments contributed to their development?
BeSS is a "Be Star Spectra" database. It was a project led by the Paris Observatory to build a database to collect professional and amateur spectra of Be stars. Professional astronomers did put in around 40000 spectra from their archive. Amateur astronomers were involved from day one on this project. A key achievement is the first definition of a FITS file format for amateurs to exchange and archive their spectra, including all needed information for later study – this is what we call the BeSS file format but it is actually a FITS based file format. It is interesting to note that BeSS is a VO (Virtual Observatory) compatible database which make it accessible from a wide range of professional tools.

ARASBeAm is a front-end for amateurs whose main objective is to answer the question: what to observe tonight? For each Be star, an ideal observing frequency is defined (once a year by default; could go to every week for delta Sco for example). Based on spectra uploaded in the database, ARASBeAm will color the Be star list with red (star requires observation), yellow (observation would be nice) or green (observation is not required at this point in time). This is very useful to ensure a good coverage of spectra among the Be stars.

Valérie Desnoux, another administrator, wrote a MS-Windows based software VisualSpec which is very user friendly and allows a direct query of BeSS. More and more comparison tools are integrated into VisualSpec for example.
Shelyak Instruments founders (François Cochard and myself) have been involved in the BeSS database design. François helped in the setup of ARASBeAm and is an administrator for the BeSS database whose role is to validate uploaded spectra are correct (good calibration, in line with previous spectra…).

Why the emphasis on Be stars?
Be stars are ideal for spectroscopy:

  • They are very bright. 30% of naked eye stars are B-type stars; about 15%-20% of those are Be stars. This makes a lot of easy targets for amateur spectroscopists.
  • Their spectra varies over time which make them fun to work with. Some vary every night (beta Lyrae for example). Some vary over longer periods of time which makes the long-time monitoring an important contribution from amateurs.
  • The BeSS/ARASBeAm is a well structured pro/am collaboration. Following the full process of acquiring spectra, processing them and uploading spectra into BeSS is highly educational. The same process can then be used for any other type of star spectra.
  • In short, amateur spectroscopists can learn on Be stars and continue for more pro/am collaboration work, an all-in-one interest!

What equipment is necessary to start learning about spectroscopy? What equipment is necessary to provide observations useful for professional / amateur collaboration?
Very low resolution spectrographs such as the Star Analyser are mainly intended to discover and learn about spectroscopy. But low resolution spectra of some targets can still be very interesting to professional astronomers: cataclysmic variables, novae, supernovae… We are sometimes lacking of professional astronomer connection to make the best of those spectra but there is definitively some interest for it. Recent observations of V407 Cyg is a good example of what an amateur can achieve in this faint target, low resolution spectroscopy field.

Higher resolution spectrographs such as Lhires III are ideal. The interchangeable grating module makes it flexible and work can be done in low resolution or high resolution. High resolution (power of resolution above 10000) reveals line profiles which can change over time (for example on Be stars but not only; supergiant active OB stars, P Cygni, bright novae… all those are also excellent pro/am collaboration targets!).

eShel is more university level equipment but is used by several amateurs who want to make a strong pro/am contribution. The advantage of eShel is that you cover the visual range in a single exposure. It has the combined benefit of low resolution (spectral domain coverage) and high resolution (line profile details). As this system is optical fiber fed, it ensures an excellent stability and spectra quality. Several exoplanets have been detected using the eShel system and there is a niche for pro/am collaboration for the search for exoplanets, especially on fast rotators which are usually left aside by professionals and where amateur equipment won't be a limitation (rotation "blurs" the spectral lines and professional higher resolution spectrographs won't bring a lot of benefit compared to eShel). My advice for beginners would be to practice with Star Analyser but move quickly to Lhires III whose opportunities are very wide. Then move to eShel to be more "productive".

What skill set is necessary for an amateur to start making a significant contribution?
The spectrograph is an additional equipment and we have found that the most productive spectroscopists are the ones who know very well how to use their telescope and their CCD camera. For data acquisition, this is the main knowledge to have.

For further analysis of the spectra, to run an educational project, a good understanding of basic mathematics and computer skill in general is required. Keep in mind that even if amateurs can go further in spectra analysis, the work done by professional astronomers usually goes beyond amateur skill sets. But what can be more enjoyable than to read a professional paper which uses some of your spectra – it can be a great eye opener!

You are organizing a star party / training class / workshop at the Observatoire de Haute Provence from August 8-13, 2010. What is the format of this event and what will attendees learn?
After Oleron school in 2003, a group of amateurs decided to organize a more practical workshop at OHP (Observatory of Haute Provence). The first one was organized in the summer of 2004 followed by the summer of 2005. In 2006, another pro/am meeting took place, then another in 2009. We had OHP workshops in 2007 and 2008 with the intent to "fill the gaps" between pro/am meetings. We kept the 2009 OHP workshop due to strong requests. In 2010, we will have our 6th OHP spectroscopy workshop.

We changed the format of the event over time. Some years we had a lot of talks during the day and observation during the night which ended too busy agenda. We moved now more to a "star party" where everyone can come with his or her instrument (about 20 telescopes and spectrographs are usually on the observing field) with daily processing workshop so everyone can learn how to use their equipment, and process their data. Objectives depend on everyone but we are trying to get most of the people to do a full process up to uploading Be star spectra in BeSS. We have also some more educational projects such as measuring the rotation of planets, measuring radial velocities of stars, measuring effective temperature of the stars, etc… OHP spectroscopy workshops became a very successful, international, friendly major event!

Is this event appropriate for intermediate amateurs as well as advanced amateurs?
This year, about half of the participants are complete beginners. It is sometimes complex to manage but our goal is that everyone will find something to learn. Emulation between participants works great every year!

Do you hold this event every year?
Yes, our intent is to run this event every year in August, at OHP observatory in the south of France. Readers should not hesitate to contact me (
olivier.thizy@shelyak.com
) in advance if they would like to attend.

It appears that the number of amateur spectroscopists in the world is fairly small. Is there anything else you would like to add to this interview to encourage people to consider professional / amateur collaboration in spectroscopy?
Fortunately, the community is growing! First, I would like to encourage everyone to try to look at the stars with new eyes by using a simple Star Analyser. It really changes our vision of the stars when we go beyond their simple brightness or colors. Looking at stellar spectral classification, measuring star effective temperature, looking at some new objects such as bright novae… all this is highly educational and one can learn by trying this!
Spectroscopy is definitively the next pro/am collaboration step. Photometry will remain important – it is usually critical to get combined photometry and spectroscopy data. The Epsilon eclipse campaign that is currently on-going is an excellent example of how important the two techniques are. But spectroscopy is revealing very important information (the result of Robin Leadbeater on KI line on epsilon Aurigae is a good example). I would encourage everyone who would like to go beyond the simple (but important) contemplation of the stars to try spectroscopy and I'm certain the virus will be caught to go further in pro/am collaboration…

Thank you very much Mr. Thizy.

Editor's Note: Here are some links that might be of interest:

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5 Responses to Spectroscopy – Interview with Olivier Thizy (Shelyak Instruments)

  1. Ken Hudson says:

    Shortly after I published this interview Robin Leadbeater posted this comment:

    “Note that although the Star Analyser (note correct spelling) is distributed by Shelyak was actually developed in the UK and is manufactured there by Paton Hawksley Education. If you are interested you can read about its development on my website.
    http://www.threehillsobservatory.co.uk/astro/spectroscopy.htm

    Robin”

  2. Ken Hudson says:

    Also, shortly after I originally posted this interview I made the following comment:

    “OHP 2010 is over. However, you can see pictures at http://www.shelyak.com/dossier.php?id_dossier=63

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