Engineering topics

Finch, Charlie T

Publications and source records attributed to Finch, Charlie T.

6 records

DOE OSTI2012

UCAC3 PROPER MOTION SURVEY. II. DISCOVERY OF NEW PROPER MOTION STARS IN UCAC3 WITH 0.''40 yr{sup -1} > {mu} {>=} 0.''18 yr{sup -1} BETWEEN DECLINATIONS -47 Degree-Sign and 00 Degree-Sign

We present 474 new proper motion stellar systems in the southern sky having no previously known components, with 0.''40 yr{sup -1} >{mu} {>=} 0.''18 yr{sup -1} between declinations -47 Degree-Sign and 0 Degree-Sign . In this second paper utilizing the U.S. Naval Observatory third CCD Astrograph Catalog (UCAC3) we complete our sweep of the southern sky for objects in the proper motion range targeted by this survey with R magnitudes ranging from 9.80 to 19.61. The new systems contribute a {approx}16% increase in the number of new stellar systems for the same region of sky reported in previous SuperCOSMOS Research Consortium On Nearby Stars (RECONS) surveys. Among the newly discovered stellar systems are 16 multiples, plus an additional ten components that are new common proper motion companions to previously known objects. A comparison of UCAC3 proper motions to those from Hipparcos, Tycho-2, Southern Proper Motion, and SuperCOSMOS indicates that all proper motions are consistent to {approx}10 mas yr{sup -1}, with the exception of SuperCOSMOS. Distance estimates are derived for all stellar systems having SuperCOSMOS Sky Survey B{sub J} , R{sub 59F}, and I{sub IVN} plate magnitudes and Two Micron All Sky Survey (2MASS) infrared photometry. We find five new red dwarf systems estimated to be within 25 pc. These discoveries support results from previous proper motion surveys suggesting that more nearby stellar systems are to be found, particularly in the fainter, slower moving samples. In this second paper utilizing the UCAC3 we complete our sweep of the southern sky for objects in the proper motion range targeted by this survey with R magnitudes ranging from 9.80 to 19.61.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2011

THE SOLAR NEIGHBORHOOD. XXV. DISCOVERY OF NEW PROPER MOTION STARS WITH 0.''40 yr{sup -1} > {mu} {>=} 0.''18 yr{sup -1} BETWEEN DECLINATIONS -47{sup 0} AND 00{sup 0}

We present 2817 new southern proper motion systems with 0.''40 yr{sup -1} > {mu} {>=} 0.''18 yr{sup -1} and declination between -47{sup 0} and 00{sup 0}. This is a continuation of the SuperCOSMOS-RECONS (SCR) proper motion searches of the southern sky. We use the same photometric relations as previous searches to provide distance estimates based on the assumption that the objects are single main-sequence stars. We find 79 new red dwarf systems predicted to be within 25 pc, including a few new components of previously known systems. Two systems-SCR 1731-2452 at 9.5 pc and SCR 1746-3214 at 9.9 pc-are anticipated to be within 10 pc. We also find 23 new white dwarf (WD) candidates with distance estimates of 15-66 pc, as well as 360 new red subdwarf candidates. With this search, we complete the SCR sweep of the southern sky for stars with {mu} {>=} 0.''18 yr{sup -1} and R{sub 59F} {<=} 16.5, resulting in a total of 5042 objects in 4724 previously unreported proper motion systems. Here we provide selected comprehensive lists from our SCR proper motion search to date, including 152 red dwarf systems estimated to be within 25 pc (9 within 10 pc), 46 WDs (10 within 25 pc), and 598 subdwarf candidates. The results of this search suggest that there are more nearby systems to be found at fainter magnitudes and lower proper motion limits than those probed so far.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2011

THE SOLAR NEIGHBORHOOD. XXIII. CCD PHOTOMETRIC DISTANCE ESTIMATES OF SCR TARGETS-77 M DWARF SYSTEMS WITHIN 25 pc

We present CCD photometric distance estimates of 100 SCR (SuperCOSMOS RECONS) systems with {mu} {>=} 0.''18 yr{sup -1}, 29 of which are new discoveries previously unpublished in this series of papers. These distances are estimated using a combination of new VRI photometry acquired at CTIO and JHK magnitudes extracted from 2MASS. The estimates are improvements over those determined using photographic plate BRI magnitudes from SuperCOSMOS plus JHK, as presented in the original discovery papers. In total, 77 of the 100 systems investigated are predicted to be within 25 pc. If all 77 systems are confirmed to have {pi}{sub trig} {>=} 40 mas, this sample would represent a 23% increase in M dwarf systems nearer than 25 pc in the southern sky.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2010

UCAC3 PROPER MOTION SURVEY. I. DISCOVERY OF NEW PROPER MOTION STARS IN UCAC3 WITH 0.''40 yr{sup -1} > {mu} {>=} 0.''18 yr{sup -1} BETWEEN DECLINATIONS -90{sup 0} AND -47{sup 0}

This paper presents 442 new proper motion stellar systems in the southern sky between declinations -90{sup 0} and -47{sup 0} with 0.''40 yr{sup -1} > {mu} {>=} 0.''18 yr{sup -1}. These systems constitute a 25.3% increase in new systems for the same region of the sky covered by previous SuperCOSMOS RECONS (SCR) searches that used Schmidt plates as the primary source of discovery. Among the new systems are 25 multiples, plus an additional 7 new common proper motion (CPM) companions to previously known primaries. All stars have been discovered using the third U.S. Naval Observatory (USNO) CCD Astrograph Catalog (UCAC3). A comparison of the UCAC3 proper motions to those from the Hipparcos, Tycho-2, Southern Proper Motion (SPM4), and SuperCOSMOS efforts is presented and shows that UCAC3 provides similar values and precision to the first three surveys. The comparison between UCAC3 and SuperCOSMOS indicates that proper motions in R.A. are systematically shifted in the SuperCOSMOS data but are consistent in decl. data, while overall showing a significantly higher scatter. Distance estimates are derived for stars having SuperCOSMOS Sky Survey B{sub J} , R{sub 59F}, and I{sub IVN} plate magnitudes and Two-Micron All Sky Survey infrared photometry. We find 15 systems estimated to be within 25 pc, including UPM 1710-5300 our closest new discovery estimated at 13.5 pc. Such new discoveries suggest that more nearby stars are yet to be found in these slower proper motion regimes, indicating that more work is needed to develop a complete map of the solar neighborhood.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2010

THE SOLAR NEIGHBORHOOD. XXII. PARALLAX RESULTS FROM THE CTIOPI 0.9 m PROGRAM: TRIGONOMETRIC PARALLAXES OF 64 NEARBY SYSTEMS WITH 0.''5 {<=}{mu}{<=} 1.''0 yr{sup -1} (SLOWMO SAMPLE)

We present trigonometric parallaxes of 64 stellar systems with proper motions between 0.''5 yr{sup -1} and 1.''0 yr{sup -1} from the ongoing Research Consortium On Nearby Stars parallax program at the Cerro Tololo Inter-American Observatory. All of the systems are south of decl. =+30, and 58 had no previous trigonometric parallaxes. In addition to parallaxes for the systems, we present proper motions, Johnson-Kron-Cousins VRI photometry, variability measurements, and spectral types. Nine of the systems are multiple; we present results for their components, three of which are new astrometric detections. Of the 64 systems, 56 are within 25 pc of the Sun and 52 of those are in the southern hemisphere, comprising 5.7% of the total number of known southern 25 pc systems.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2010

UCAC3: ASTROMETRIC REDUCTIONS

Presented here are the details of the astrometric reductions from the x, y data to mean right ascension (R.A.), declination (decl.) coordinates of the third U.S. Naval Observatory CCD Astrograph Catalog (UCAC3). For these new reductions we used over 216,000 CCD exposures. The Two-Micron All-Sky Survey (2MASS) data are used extensively to probe for coordinate and coma-like systematic errors in UCAC data mainly caused by the poor charge transfer efficiency of the 4K CCD. Errors up to about 200 mas have been corrected using complex look-up tables handling multiple dependences derived from the residuals. Similarly, field distortions and sub-pixel phase errors have also been evaluated using the residuals with respect to 2MASS. The overall magnitude equation is derived from UCAC calibration field observations alone, independent of external catalogs. Systematic errors of positions at the UCAC observing epoch as presented in UCAC3 are better corrected than in the previous catalogs for most stars. The Tycho-2 catalog is used to obtain final positions on the International Celestial Reference Frame. Residuals of the Tycho-2 reference stars show a small magnitude equation (depending on declination zone) that might be inherent in the Tycho-2 catalog.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗