Mark R. Boyd

The solar neighborhood. XXXV. Distances to 1404 M dwarf systems within 25 PC in the southern sky

We present trigonometric, photometric, and photographic distances to 1748 southern (d  ⩽ 0 ) M dwarf systems with  ⩾ μ 01 8 · yr �1 , of which 1404 are believed to lie within 25 pc of the Sun. The stars have ⩽⩽ V 6.67 21.38 J and ⩽⩽ VK 3.50 ( ) 9.27 Js , covering the entire M dwarf spectral sequence from M0.0 V through M9.5 V. This sample therefore provides a comprehensive snapshot of our current knowledge of the southern sky for the nearest M dwarfs that dominate the stellar population of the Galaxy. Roughly one-third of the 1748 systems, each of which has an M dwarf primary, have published high quality parallaxes, including 179 from the REsearch Consortium On Nearby Stars astrometry program. For the remaining systems, we offer photometric distance estimates that have well-calibrated errors. The bulk of these (∼700) are based on new V RI J KC KC photometry acquired at the CTIO/ SMARTS 0.9 m telescope, while the remaining 500 primaries have photographic plate distance estimates calculated using SuperCOSMOS B RI JF 59 IVN photometry. Confirmed and candidate subdwarfs in the sample have been identified, and a census of companions is included.

THE SOLAR NEIGHBORHOOD. XXVII. DISCOVERY OF NEW PROPER MOTION STARS WITH μ 0. 18 yr −1 IN THE SOUTHERN SKY WITH 16.5 <R 59F 18.0

Here we present 1584 new southern proper motion systems with μ0. �� 18 yr −1 and 16.5 >R 59F 18.0. This search complements the six previous SuperCOSMOS-RECONS (SCR) proper motion searches of the southern sky for stars within the same proper motion range, but with R59F 16.5. As in previous papers, we present distance estimates for these systems and find that three systems are estimated to be within 25 pc, including one, SCR 1546-5534, possibly within the RECONS 10 pc horizon at 6.7 pc, making it the second nearest discovery of the searches. We find 97 white dwarf candidates with distance estimates between 10 and 120 pc, as well as 557 cool subdwarf candidates. The subdwarfs found in this paper make up nearly half of the subdwarf systems reported from our SCR searches and are significantly redder than those discovered thus far. The SCR searches have now found 155 red dwarfs estimated to be within 25 pc, including 10 within 10 pc. In addition, 143 white dwarf candidates and 1155 cool subdwarf candidates have been discovered. The 1584 systems reported here augment the sample of 4724 systems previously discovered in our SCR searches and imply that additional systems fainter than R59F = 18.0 are yet to be discovered.