Calculation of the Local Standard of Rest from 20,574 Local Stars in the New Hipparcos Reduction with Known Radial Velocities

Abstract

Context. An accurate estimate of the local standard of rest (LSR) is required to determine key parameters used in approximate galactic mass models and to understand Galactic structure and evolution. However, authors are often forced to base dynamical analyses on potentially unreliable figures because recent determinations of the LSR have failed to reach agreement, especially with regard to the direction, V, of Galactic rotation. Aims. To explain why the traditional method for calculating the LSR fails, and to find alternative means of calculating the LSR with realistic error margins. Methods. We assemble and investigate the kinematic properties of 20 574 stars within 300pc, with complete and accurate kinematic data. The traditional method of calculating the LSR assumes a well-mixed distribution. In fact, the velocity distribution is highly structured, invalidating calculations based on mean motions and asymmetric drift. We find other indicators in the distribution which we believe give a better estimate of circular motion. Results. We find good agreement between results and give as our best estimate of the LSR (U_0, V_0, W_0) = (7.5 +- 1.0, 13.5 +- 0.3, 6.8 +- 0.1) km/s. We calculate the slope of the circular speed curve at the solar radius, finding -9.3 +- 0.9 km/s/kpc.

12 pages, 29 figures, 4 tables. A high resolution version of this file is available from http://www.teleconnection.info/papers/LSRhires.pdf (8MB)

References in corpus (4)

• Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Southern Sample
• The Geneva-Copenhagen Survey of the Solar neighbourhood II. New uvby calibrations and rediscussion of stellar ages, the G dwarf problem, age-metallicity diagram, and heating mechanisms of the disk
• Phase Space Structure in the Solar Neighbourhood
• Quantifying Chaos in Models of the Solar Neighbourhood

Cited by in corpus (14)

• Stellar Abundances in the Solar Neighborhood: The Hypatia Catalog
• The observed spiral structure of the Milky Way
• Star formation near the Sun is driven by expansion of the Local Bubble
• The origin of large peculiar motions of star-forming regions and spiral structures of our Galaxy
• Determination of the Local Standard of Rest using the LSS-GAC DR1
• Significance Mode Analysis (SigMA) for hierarchical structures. An application to the Sco-Cen OB association
• 3D dynamics of the Orion cloud complex -- Discovery of coherent radial gas motions at the 100-pc scale
• Local Stellar Kinematics and Oort Constants from the LAMOST A-type Stars
• VLBI Astrometry of AGB Variables with VERA -- A Mira Type Variable T Lepus
• The local standard of rest from data on young objects with account for the Galactic spiral density wave
• High-Drag Interstellar Objects And Galactic Dynamical Streams
• The GAPS programme at TNG XXXIV. Activity-rotation, flux-flux relationships, and active region evolution through stellar age
• The GAPS programme at TNG XLIII. A massive brown dwarf orbiting the active M dwarf TOI-5375
• Lindblad's epicycles - valid method or bad science?