The K2-OjOS project (K2 OJimetrO Survey) is a pro - am and outreach collaboration of the Instituto de Ciencias y Tecnologías del Espacio (ICTEA) of the University of Oviedo with members of the Sociedad Astronómica Asturiana Omega. The main aim of the project is to search and classify exoplanets and variable stars, starting from data obtained by the Kepler Space Telescope in its extended mission K2.
Up to now, we have inspected K2's campaign 18, which contains 20427 stars. We have divided the campaign in 21 batches of 1000 stars each one (except the last one which has 427 stars). Each batch is examined by a member of the collaboration.
In the first place read this tutorial to learn how to download the data and identify potentially interesting stars:
1) Tutorial for characterizing variable stars and exoplanets using K2 data
2) Tutorial with examples of the main variable type of stars we will find
In the second place, access to this spreadsheet.
In the tab Lots all the different lots are listed down, 1000 stars each one. Select a lot which is not still assigned to anyone, noting down your name in the User column. The link that appears in the column CSV List contains a file with the list of stars corresponding to that lot. You can download and open it with Excel, LibreOffice Calc or similar.
When examining the stars (following the tutorial mentioned above) you will find stars with interesting light curves. Note them down in the Candidates tab located at the spreadsheet.
Sometimes you will see there are several collaborators using the spreadsheet at the very same time. Here are some tips to avoid possible conflicts that could arise when trying to edit simultaneously the same cells:
You can use Google Drive Chat to communicate with them.
You can also leave blank several lines and add data below, therefore leaving some space to avoid colliding with other users.
You can change the background color of several lines to show that you are going to be working in that area of the spreadsheet. Remember to erase that background color once you are done editing them.
When you have finished examining a lot, tick the cell Completed in the correspondent line at the tab Lots and select a new lot to continue working.
Once all the K2's campaign 18 stars have been inspected, we will move on to confirm and obtain the necessary data from the variable stars that are among the easiest to identify: eclipsing, delta scuti and rr lyrae. To do this, we will follow these steps:
We will check and analyze all the variable stars found in lots that have been previously inspected by other collaborator from the Project. For that, we will assign those lots as we did in the Phase 1 (be careful, it is about reviewing ONLY those stars identified as variables, NOT ALL the stars in the lot again). This is how we will perform a double check.
For now we will only analyze variable stars catalogued as eclipsing binaries, delta scuti and rr lyrae, clearly unmistakable.
It is important to identify the stars that belong to the Beehive Cluster (M44) or to M67, both in the field of K2's campaign 18. For that we have to perform a search (AR and Dec) of the star at Vizier, go to the chart of Gaia DR2 and verify the star's distance and own movements. If they match the average values from this clusters' members, we might have unveiled their belonging. Here is a quick guide on how to do this.
Note down this values (period, AR coordinates and Dec, distance to the star, own movements and radial velocity) in the spreadsheet so we can identify the star as a member of M44 or M67.
For the Light curve analysis we will use a couple of programs (notebooks written in Python language) specifically developed for this Project. We will use the Google Colab platform, that allows us to run the notebooks in the cloud without having to install the development environment in every computer.
These are the notebooks:
• Analysis by GLS method. For stars with a continuous variability, like pulsating, rotating or Type EB or EW binaries.
• Analysis by BLS method. For stars with relatively short transits in comparison with their period, like happens in EA type binaries or planets.
Some stars will work better with the first method and others with the second. In case of doubt it is possible to try both and choose the one that leaves a cleaner phase curve.
After running these programs we will write down at the spreadsheet the following data in the correpondent columns of the Candidates tab:
Method used (GLS or BLS)
Period
T0 (epoch)
Amplitude
Besides we will save the phase curve image in PNG format with a filename under the format EPICXXXXXXXXX_phase.png which we will after copy to this Google Drive folder.
Scientific production
Publications:
1) A. Castro González et al., Accepted for publication in Monthly Notices of the Royal Astronomical Society: The K2OJOS project: New and revisited planets and candidates in K2 campaigns 5, 16 & 18
Conferences and meetings:
1) A. Castro González et al., 2020: Exoplanets and variable stars in K2 data. A Pro-Am collaboration
Student Research Projects
Estrellas variables en la campaña 18 del telescopio espacial Kepler en su misión extendida K2 (David Canal’s Master’s Thesis analyzing the variable stars found throughout the project )
Outreach
K2-OjOs talk (Agrupación Astronómica de Madrid, 22/04/2025):
K2-OjOS talk (Federación de Asociaciones Astronómicas de España - Comisión Pro Am de la Sociedad Española de Astronomía, 16/12/2021)
News on Asturias Informativos (RTVE, minute 42, 30/11/2021)
News on the Radio Relevision del Principado de Asturias (10/11/2021)
Colaboraciones Pro - Am (Xataca, 23/10/2021)
K2-OjOS: una colaboración Pro - Am en busca de nuevos mundos (Astronomía magazine, September 2021
K2-OjOS talk (Federación de Asociaciones Astronómicas de España - Comisión Pro Am de la Sociedad Española de Astronomía, 16/12/2021)
News on Asturias Informativos (RTVE, minute 42, 30/11/2021)
News on the Radio Relevision del Principado de Asturias (10/11/2021)
Colaboraciones Pro - Am (Xataca, 23/10/2021)
K2-OjOS: una colaboración Pro - Am en busca de nuevos mundos (Astronomía magazine, September 2021)
Awards
Javier Gorosabel Award for Pro-Am Collaboration, granted by the Spanish Astronomical Society (SEA) at its 16th Scientific Meeting, held in Granada from July 15 to 19, 2024. Link to the news on the SEA website.
K2-OjOS team
At the moment the K2-OjOS crew is made up of researchers from the Instituto Universitario de Ciencias y Tecnologías del Espacio de Asturias (ICTEA) and 11 amateur astronomers belonging to Sociedad Astronómica Asturiana Omega:
J. Menéndez Blanco, A. Coya Lozano, F. García de la Cuesta, N. Gómez Hernández, R. Hevia Díaz, P. Padilla Tijerin, R. Pardo Silva, S. Pérez Acevedo, J. Polancos Ruiz, D. Vázquez García, J. R. Vidal Blanco
Acknowledgements
We are very grateful to Pia Valentin Sørensen ( https://www.artmajeur.com/pia-valentin-sorensen ) for designing the K2-OjOS logo and stunning illustrations for the outreach activities.
-The whole is more than the sum of its parts-
