GG Tauri

At a distance of about 450 light years (140 parsecs) away, it is located within the Taurus-Auriga Star Forming Region.

[19] Its large size and close distance make it ideal to study how exoplanets form within multiple star systems.

[22] These stars are extremely young and more luminous than their main sequence counterparts, because they have not condensed into the normal size yet.

[11] A preliminary orbit for GG Tauri Aa and Ab has been calculated,[11] but is not very well constrained.

[23] However, other studies have found the orbit to be coplanar to the circumbinary disk, with a larger semimajor axis of about 60 au.

[12] Interferometric techniques have been used to observe GG Tauri Ab, the lower-mass component of the central system.

GG Tauri Ab was found to be a binary star system comprising two red dwarfs (Ab1 = M2V, Ab2 = M3V), with a separation of about 4.5 AU.

This would explain why the GG Tauri Ab's spectrum suggests an unusually low-mass star instead of the higher mass that was measured.

[15] The disk around GG Tauri Aa has a mass of about 0.1 M☉, or about the mass of Jupiter,[26] at a temperature of about 20 to 30 K.[27] GG Tauri Aa appears to have a jet coming out from the poles, as evidenced by forbidden Fe II lines.

[31] At the center of this "hot spot" may be a protoplanet termed GG Tauri Ac, which is still accreting mass.

A visual band light curve for GG Tauri, adapted from Bouvier et al. (1993) [ 21 ]
Artist's impression of the circumstellar disk surrounding GG Tauri A