DG Tauri

DG Tauri
NASA/CXC/M.Weiss · Public domain · source
Name	DG Tauri
Epoch	J2000
Constellation	Taurus
Type	T Tauri
Spectral type	K6–M0
Mass	~0.7–0.8 M☉
Age	~1 Myr
Distance	~140 pc

DG Tauri

Introduction

DG Tauri is a young pre-main-sequence T Tauri object located in the Taurus–Auriga constellation near the Taurus Molecular Cloud and the L1495 region. Observed in optical, infrared, and radio bands by facilities such as the Hubble Space Telescope, the Atacama Large Millimeter/submillimeter Array, and the Very Large Telescope, it serves as a prototype for studies of accretion, disk evolution, and jet launching in stellar nurseries like the Orion Nebula and the Rho Ophiuchi cloud complex. DG Tauri lies in a star-forming environment surveyed by missions including Spitzer Space Telescope, WISE, and Gaia.

Stellar properties

DG Tauri is classified as a classical T Tauri star with a spectral type near K6–M0, similar to other young objects such as HL Tauri and RY Tauri. Estimates of its stellar mass and radius derive from pre-main-sequence evolutionary tracks by groups associated with Baraffe et al., Siess et al., and D'Antona & Mazzitelli, and place it at roughly 0.7–0.8 solar masses and a few solar radii, comparable to objects in the Taurus-Auriga association. Its effective temperature, surface gravity, and luminosity have been studied with instruments on the Keck Observatory and the Subaru Telescope, and its position and parallax are measured by Gaia Data Release 2 and later catalogues. Photometric and spectroscopic characterization links DG Tauri to accretion diagnostics used for stars observed with the Sloan Digital Sky Survey and the Calar Alto Observatory.

Protoplanetary disk and accretion

DG Tauri hosts an actively accreting protoplanetary disk detected in continuum and line emission by ALMA, the Plateau de Bure Interferometer, and the James Clerk Maxwell Telescope. The disk shows signatures of dust continuum, molecular gas tracers such as CO isotopologues studied in surveys by the IRAM consortium and the JCMT Gould Belt Survey, and a radial structure compared with the transitional disks around TW Hydrae and DM Tau. Accretion rates inferred from Hα, Brγ, and UV excess measurements obtained with the Hubble Space Telescope and ground-based spectrographs like VLT/X-shooter indicate values typical for classical T Tauri stars, consistent with models of viscous accretion by theorists associated with Lynden-Bell & Pringle and with magnetospheric accretion frameworks developed in studies by Koenigl and Hartmann. Dust grain growth and disk chemistry in DG Tauri are compared to results from planet-forming systems such as HL Tauri imaged by ALMA Partnership.

Bipolar jets and outflows

DG Tauri exhibits a well-collimated bipolar jet and molecular outflow observed in forbidden lines ([O I], [S II]) and molecular transitions (CO, H2) by HST imaging, Keck Observatory spectroscopy, and radio interferometers including ALMA and the Very Large Array. The jet shows knotty shock structures analogous to those seen in the HH 34 and HH 111 Herbig–Haro systems and is associated with high-velocity components studied in works that reference the Bally surveys of outflows. Proper-motion measurements and emission-line diagnostics connect the jet to magnetohydrodynamic launching scenarios proposed by Blandford & Payne and Pudritz & Norman, and to disk-wind models explored by groups at Cambridge University and the Max Planck Institute for Astronomy. Observations of radio continuum and X-ray emission with the Chandra X-ray Observatory reveal internal shocks and jet–ambient medium interactions comparable to phenomena in jets from DG Tau B and other young stellar objects catalogued by the Herbig–Haro object surveys.

Variability and photometry

DG Tauri displays irregular photometric and spectroscopic variability across optical to infrared bands recorded by monitoring programs at Mount Hopkins, the Robotic Optical Transient Search Experiment, and the All-Sky Automated Survey for Supernovae. Variability is associated with accretion bursts, veiling, and occultation events analogous to behavior in stars like AA Tauri and EX Lupi. Time-series analyses use period-search techniques developed in the OGLE and Kepler projects to characterize quasi-periodic signals that may relate to rotation modulations tied to magnetic spots and inner-disk inhomogeneities studied in models by Romanova and collaborators. Multiwavelength campaigns coordinating Spitzer, HST, and ground-based facilities have linked photometric changes to spectroscopic tracers of mass accretion and outflow activity.

Surrounding environment and companions

DG Tauri resides in a clustered environment within the Taurus Molecular Cloud complex near other young stars such as RW Aurigae and UY Aurigae. High-resolution imaging and interferometric surveys with instruments like Keck/NIRC2, VLT/NACO, and VLTI" have searched for stellar and substellar companions analogous to companions found around GG Tau and DH Tauri, with constraints informing multiplicity statistics from studies by teams at Harvard–Smithsonian Center for Astrophysics and Max Planck Institute for Astronomy. Circumstellar material, reflected nebulosity, and shocks in the ambient cloud link DG Tauri to larger-scale processes mapped by the Spitzer Space Telescope and the Herschel Space Observatory. Observations of nearby molecular cores and filaments relate DG Tauri to the structure of the L1495 filament and to feedback mechanisms explored in work by the Carnegie Institution for Science and Institute of Astronomy, Cambridge.

Category:T Tauri stars