Description: T-Tauri stars are a class of low mass young variable stars. They are named after the prototype, T-Tauri, a variable star in the Taurus star-forming region. T-Tauri variables are found in groups of young stars. Their "surface" temperatures (effective temperatures) are similar to those of F, G, K, and M spectral type main sequence stars of the same mass, but they are significantly more luminous because their diameter is larger. These contracting young stars have not started fusing hydrogen and are powered by the release of gravitational energy during their contraction. T-Tauri stars can be identified by their irregular optical variability and spectrum. They emit intense and variable X-ray and radio waves. Brightness variability is also caused by clumps in the circumstellar disk surrounding T-Tauri stars.

Related Terms:

• Hydrogen Fusion
• Main Sequence
• Protostar
• Radio Waves
• Spectral Type
• Star Formation
• Taurus
• Effective Temperature
• Variable Star
• X-ray
• Pre-main-sequence Star

Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".