HD 36112

HD 36112, also known as MWC 758, is a young Herbig Ae star located in the constellation Taurus, surrounded by irregular rings of cosmic dust. The system is about 3.5 million years old. The disk has a cavity at 50 astronomical units and two spiral arms at 30-75 au that are seen in near-infrared scattered light, but only one spiral arm is seen in ALMA images.^[9][4]

HD 36112

HD 36112 and the surrounding dusty disk. The rings in the disk were measured as being elliptical in shape rather than being perfectly circular. Credit: ESO/R. Dong et al.; ALMA (ESO/NAOJ/NRAO)
Observation data Epoch J2000      Equinox J2000
Constellation	Taurus[1]
Right ascension	05h 30m 27.52856s[2]
Declination	+25° 19′ 57.0763″[2]
Apparent magnitude (V)	8.27[3]
Characteristics
Evolutionary stage	pre main sequence[4]
Spectral type	A8Ve[5]
Astrometry
Proper motion (μ)	RA: 3.685(33) mas/yr[2] Dec.: −26.373(22) mas/yr[2]
Parallax (π)	6.4157±0.0314 mas[2]
Distance	508 ± 2 ly (155.9 ± 0.8 pc)
Details
Mass	1.6[6] M☉
Radius	2.0[7] R☉
Luminosity	10[6] L☉
Surface gravity (log g)	4.05[7] cgs
Temperature	7,600[6] K
Metallicity [Fe/H]	0.10[8] dex
Age	8.0[6] Myr
Other designations
MWC 758, BD+25 843, HIP 25793, 2MASS J05302753+2519571, IRAS 05273+2517
Database references
SIMBAD	data

The inner cavity was shown to be elliptical and not perfectly circular. This is not a projection effect but represents the shape of the cavity, with an eccentricity e ≈ 0.1 after the deprojection of the disk.^[4]

A light curve for HD 36112, plotted from ASAS-SN data^[10]

A 2018 study detected a possible exoplanet at a distance of about 20 au, designated MWC 758 b,^[11] and the observations with ALMA have also shown evidence of an unseen planet at 100 au.^[4] A study in 2019 came to the conclusion that a 1.5 M_J planet at 35 au and a 5 M_J planet at 140 au could explain the features seen with ALMA and the VLA.^[12]

In another 2019 study, a possible exoplanet or disk feature was detected with the Large Binocular Telescope, referred to as MWC 758 CC1 (Companion Candidate 1), with a non-detection of MWC 758 b.^[13] However, another study in 2021 failed to detect either of the point sources found in earlier studies.^[14] A 2023 study found further evidence for MWC 758 CC1, now designated MWC 758 c, orbiting at a distance of approximately 100 au.^[15]