HAT-P-41 is a

binary star A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in wh ...

system. Its primary is a

F-type main-sequence star An F-type main-sequence star (F V) is a main-sequence, hydrogen-fusing star of spectral type F and luminosity class V. These stars have from 1.0 to 1.4 times the mass of the Sun and surface temperatures between 6,000 and 7,600 K.Tables VII ...

. Its surface temperature is 6390 K. compared to the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

, HAT-P-41 is enriched in heavy elements, with a

metallicity In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal physical matter in the Universe is either hydrogen or helium, and astronomers use the word ''"metals"'' as a ...

Fe/H index of 0.21, but is much younger at an age of 2.2 billion years. The candidate stellar companion was detected simultaneously with the planet discovery in 2012. A multiplicity survey in 2015 did confirm a dim stellar companion of later-K to early-M spectral class, with the probability of being a background star of 14%. By 2020, it was concluded the candidate companion star is probably gravitationally bound.

Planetary system

In 2012, one planet, named

HAT-P-41b HAT-P-41 is a binary star system. Its primary is a F-type main-sequence star. Its surface temperature is 6390 K. compared to the Sun, HAT-P-41 is enriched in heavy elements, with a metallicity In astronomy, metallicity is the abundan ...

, was discovered on a tight, circular orbit around the primary star. The planetary orbit is mildly misaligned with the equatorial plane of the star, misalignment angle equal to −22.1 degrees. The transmission spectrum of

taken in 2020 has resulted in contradictory interpretations. One team has concluded the planetary atmosphere is metal-rich, with clear water signatures and absorption bands from sodium, aluminum, titanium and vanadium compounds. Another team has interpreted the results as arising from a dense hydrogen atmosphere without detectable heavy elements, but with significant ionization. The atmosphere also appears to contain significant cloud and hazes. Neither heavy element compounds nor H⁻ ion opacity were found in 2022 study. The planetary equilibrium temperature is within 1700-1950 K, and the dayside temperature has been measured at 1622 K.

References

{{Stars of Aquila Binary stars Aquila (constellation) Planetary transit variables F-type main-sequence stars Planetary systems with one confirmed planet J19491743+0440207