Southern Infrared Proper Motion Survey I: Discovery of New High Proper Motion Stars From First Full Hemisphere Scan

TL;DR

This paper introduces the first widefield infrared proper motion survey in the southern hemisphere, discovering new high proper motion stars, including nearby M, L, and T dwarfs, and analyzing their properties and survey limitations.

Contribution

It presents the first southern infrared proper motion survey combining 2MASS and SuperCOSMOS data, discovering 72 new high proper motion objects and analyzing their characteristics.

Findings

Discovered 72 new high proper motion stars.

Measured a parallax for a late M dwarf at 3.62 pc.

Identified a common proper motion triple system.

Abstract

We present the first results from the Southern Infrared Proper Motion Survey. Using 2 Micron All Sky Survey data along with that of the SuperCOSMOS sky survey we have been able to produce the first widefield infrared proper motion survey. Having targeted the survey to identify nearby M, L and T dwarfs we have discovered 72 such new objects with proper motions greater than 0.5''/yr with 10 of these having proper motions in excess of 1''/yr. The most interesting of these objects is SIPS1259-4336 a late M dwarf. We have calculated a trigonometric parallax for this object of $\pi = 276 \pm 41$ milliarcseconds yielding a distance of $3.62\pm0.54$pc. We have also discovered a common proper motion triple system and an object with a common proper motion with LHS 128. The survey completeness is limited by the small epoch differences between many 2MASS and UKI observations. Hence we only recover 22% of Luyten objects with favourable photometry. However the Luyten study is itself unquantifiably incomplete. We discuss the prospect of enhancing the survey volume by reducing the lower proper motion limit.