HAT-P-21b orbits the dwarf star G3 V = 11.685 GSC 3013-01229 in an eccentric orbit (e = 0.228 ± 0.016), with a period P = 4.124481 ± 0.000007 days, transit time Tc = 2454996.413106.41312 0 and transit duration. 0.1530 ± 0.0027 days. The host star has a mass of 0.95 ± 0.04 M☉, radius of 1.10 ± 0.08 R☉, effective temperature of 5588 ± 80 K and metallicity [Fe/H] = +0.01 ± 0.08.
The planetary companion has a mass of 4.063 ± 0.161 MJ and a radius of 1.024 ± 0.092 RJ, giving an average density of 4.68+1.59− 0.99 g cm−3. HAT-P-21b is a boundary object between the pM and pL class planets, and transits occur near a pastron.
https://arxiv.org/abs/1008.3388
Observations of HAT-P-22b
Collaborative projects
