The Sunspot Number is the longest scientific experiment still ongoing and a crucial benchmark to study solar activity, space weather and climate change. The Royal Observatory of Belgium (ROB) plays a central role in the continuation of this experiment, as it hosts the Sunspot Index and Long-term Solar Observations World Data Center (SILSO-WDC). This World Data Center aims at collecting solar data, as well as producing and distributing the International Sunspot Number, which is used in about two hundred scientific publications on an annual basis.
The Val-u-Sun project hinges on two sunspot collections kept at ROB. The first collection consists of a series of about 20.000 digitized sunspot drawings acquired at the Uccle Solar Equatorial Table station (USET) since 1940 and a corresponding database. The second collection, the SILSO database, contains the numbers of spots and groups of spots on the Sun observed by a worldwide network since 1981 (more than 530.000 measurements).
The objective to achieve on these two collections is threefold: (1) Bring the databases to the modern era by adding essential metadata, whether it is additional parameters or techniques for quality assessment and quality control. (2) Use the value of solar parameters recorded in these databases to address today’s scientific questions and (3) disseminate the collections and added value.
For this, modern methods for statistical quality control must be used and adapted. As this is a growing database that still receives data on a daily basis, the process of determining a multi-station reference needs to be done dynamically. For statistical purposes, the project needs everyone with different backgrounds, a different knowledge and experience. The Val-u-Sun team has set up a citizen science website where you'll be guided through a fairly simple tutorial. You'll learn about the way people who actually work as solar observers draw and count sunspot groups. And finally you will be asked to count them as any other solar observer.
So, you can help the project by counting sunspots and groups of sunspots on the original drawings from the ROB's archive. A selection of drawings has been made, from different phases of the Sun's activity. Some have a lot of sunspots and sunspot groups, some have only a few. The drawings you get have already been counted and analyzed by the project team. The goal of this project is to compare statistically the number of sunspots counted by the project team against those found by others. Since the drawing and counting of the sunspots can be a little subjective, some point of comparison is needed. That would be you, dear reader! No worries: there is no good or bad answer, your best effort is perfect.
This citizen science project "Val-u-Sun" started already in October last year, but it is now also available in Nederlands and en Français! Spread the word, and enjoy!
