NOAK Observatory (L02)

Exoplanet transits from their parent star

The observatory participates in two groups submitting transit time measurements. One is the Exoclock Team which is responsible for accurately checking the transit times of 1000 exoplanets in front of their parent star so that in 2029, when ESA's ARIEL spacecraft launches, it can study how they were created, their atmosphere and their chemical composition. The second is called Exoplanet Watch and is part of NASA. Its aim is to collate, as far as possible, all the measurements made concerning exoplanets and submit them to the AAVSO database. For more information on the pages: and .

Testing photometry programmes involving exoplanets.

Four of the most important photometric programs for studying the passage of an exoplanet in front of its parent star that are widely used by amateur and professional astronomers are HOPS, AstroImageJ, EXOTIC and Muniwin. HOPS is the program used by the vast majority of users to create a photometric curve of an exoplanet. This is because these measurements are collected in ESA's database called EXOCLOCK and will be used in the 2029 ARIEL space mission to study the physical characteristics of 1000 exoplanets. The community in Greece includes 15 people if I'm not mistaken and is growing all the time. This is also due to the fact that the creator of the project is Greek (Angelos Tsiaras) and the coordination of the presentation to the public of the whole project belongs to Anastasia Kokori. The program is very user-friendly and its interface is based on the PYTHON language. On the Exoclock website you can find detailed information on how you can participate in this very worthwhile and ambitious project. In this way the measurements of an amateur are of great value to the scientific community. AstroImageJ is a photometry program that was also used in the data analysis of the TESS mission. It is more widely used on the other side of the Atlantic and by professional astronomers. It is a program that is also used to study exoplanets primarily and less so for variable stars and asteroids. Personally I think it is aimed at people with more knowledge of the subject, although with enough practice one can do it. It has too many parameters that will cover every aspect to properly create the curve. EXOTIC is the photometry program proposed by NASA for the analysis of a passage. It is also easy to install, based on the PYTHON programming language. What I didn't like about handling this particular program is its complete automation. Apart from entering some critical parameters, you don't do anything else. The good thing is that you can save your measurements and submit them to AAVSO. Finally Muniwin. A program that does it all and it pays off. Very easy to use with a very nice interface, it makes it easy for the most inexperienced observer to build a photometric curve for variable stars, asteroids and exoplanets. It is used by many people and there is a lot of information on the web. Also the measurement results can be stored in various formats to be submitted to many databases e.g. AAVSO, ETD etc. Which program one chooses is purely subjective. In the end, however, I truly believe that one of the most beautiful feelings an astronomer (amateur or not) can feel is at the end of this process to see the photometric curve appears on the computer screen!