A5027581046- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- History and Developments in Astronomy
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Pulsars and Gravitational Waves Research
- Calibration and Measurement Techniques
- Spectroscopy and Laser Applications
- Galaxies: Formation, Evolution, Phenomena
- Geophysics and Gravity Measurements
- High-pressure geophysics and materials
- Atmospheric Ozone and Climate
- Scientific Research and Discoveries
- Planetary Science and Exploration
- CCD and CMOS Imaging Sensors
- Astrophysics and Cosmic Phenomena
- Infrared Target Detection Methodologies
- Solar and Space Plasma Dynamics
- Historical Geography and Cartography
- Geographic Information Systems Studies
- Impact of Light on Environment and Health
Australian National University
2016-2025
ARC Centre of Excellence for All-sky Astrophysics
2019-2025
ASTRO-3D
2019-2024
Mount Stromlo Observatory
2008-2023
Australian Research Council
2019
University of Chile
2014
ACT Government
1979-2014
Joint Institute for Nuclear Astrophysics
2008
Michigan State University
2008
Uppsala University
2008
The relations between colors of the JHKL systems several observatories are examined, and linear derived for transformation (J-K), (J-H), (H-K), (K-L) in different systems. A homogenized system is proposed, based on Glass (1984) Johnson et al. (1966). data sets used to derive intrinsic a number giants dwarfs. passbands IR estimated synthetic compared using blackbody stellar fluxes. were adjusted wavelength produce agreement with observed systems, making it possible estimate effective...
Good representations of the passbands for Johnson-Cousins UBVRI system have been devised by comparing synthetic photometry with actual observations and standard magnitudes. Small adjustments made to previously published passbands. Users are urged match these so that better calibration ensured. Mismatched B bands shown be a major source recent (U - B) transformation problems. The nature systematic differences between natural colors most widely used sets star is investigated suggested CCD...
The Cousins VRI system is proposed as an ideal to adopt the standard for both Northern and Southern Hemisphere near-IR observations. Comparisons are made between (b-y), (G-R)6, (V-I)jJ, (V-I)C color indices measured a large sample of equatorial HR stars which illustrate precision excellent temperature sensitivity (V- I)C index. Transformations different systems including Eggen-Kron derived, calibration (R-I)C, provided based on empirical determinations, absolute flux UBVRI derived.Photometry...
Various effective temperature scales have been proposed over the years. Despite much work and high internal precision usually achieved, systematic differences of order 100 K (or more) among various are still present. We present an investigation based on Infrared Flux Method aimed at assessing source such discrepancies pin down their origin. break impasse different by using a large set solar twins, stars which spectroscopically photometrically identical to Sun, absolute zero point scale...
Abstract This paper presents the design and science goals for SkyMapper telescope. is a 1.3-m telescope featuring 5.7-square-degree field-of-view Cassegrain imager commissioned Australian National University's Research School of Astronomy Astrophysics. It located at Siding Spring Observatory, Coonabarabran, NSW, Australia will see first light in late 2007. The possesses 16 384 × 0.5-arcsec pixels. primary scientific goal facility to perform Southern Sky Survey, six-colour multi-epoch...
Following the 1983 IRAS detection and subsequent imaging of its extensive dusty circumstellar disk, β Pictoris became prototypical most studied example a potential forming planetary system. Here we report identification 17 star systems, each with one or more characteristics indicative extreme youth, that are moving through space together Pic. This diverse set ~12 million yr old which includes ~35 Jupiter mass brown dwarf, wide assortment disks, is comoving, youthful group closest to Earth....
We present the results of analysis "snapshot" spectra 253 metal-poor halo stars obtained in HERES survey. The snapshot have been with VLT/UVES and typically per pixel (ranging from 17 to 308), , –4980 Å. This sample represents major part complete 373 stars; however, CH strong content is not dealt here. are analysed using an automated line profile method based on Spectroscopy Made Easy (SME) codes Valenti & Piskunov. Elemental abundances moderate precision (absolute rms errors order 0.25 dex,...
▪ Abstract Standard star photometry dominated the latter half of twentieth century reaching its zenith in 1980s. It was introduced to take advantage high sensitivity and large dynamic range photomultiplier tubes compared photographic plates. As quantum efficiency photodetectors improved wavelength extended further red, standard systems were modified refined, deviations from original proliferated. The revolutionary shift area detectors for all optical IR observations forced changes systems,...
We present the first data release (DR1) of SkyMapper Southern Survey, a hemispheric survey carried out with Telescope at Siding Spring Observatory in Australia. Here, we strategy, processing, catalogue construction and database schema. The DR1 dataset includes over 66,000 images from Shallow Survey component, covering an area 17,200 deg$^2$ all six passbands $uvgriz$, while full covered by any passband exceeds 20,000 deg$^2$. catalogues contain 285 million unique astrophysical objects,...
With a combination of adaptive optics imaging and multi-epoch common proper motion search, we have conducted large volume-limited (D ≤ 75 pc) multiplicity survey A-type stars, sensitive to companions beyond 30 au. The sample for the Volume-limited A-STar (VAST) consists 435 stars: 363 stars were observed with optics, 228 searched wide 156 measured both techniques. projected separation coverage VAST extends from 45 000 A total 137 stellar resolved, including 64 new detections survey,...
We present a homogeneous chemical abundance analysis of 16 elements in 190 metal-poor Galactic halo stars (38 program and 152 literature objects). The sample includes 171 with [Fe/H] ⩽ −2.5, which 86 are extremely metal poor, −3.0. Our include 10 new objects −3.5. identify "normal" measure the trends between [X/Fe] [Fe/H], as well dispersion about mean trend for this sample. Using trend, we that chemically peculiar relative to at same metallicity. These unusual CEMP-no objects, one star high...
We propose 35 star systems within ∼70 pc of Earth as newly identified members nearby young stellar kinematic groups; these identifications include the first A- and late-B-type AB Doradus moving group field Argus Association. All but one contain a bright solar- or earlier-type that should make an excellent target for next generation adaptive optics (AO) imaging on large telescopes. AO has revealed four massive planets in orbit around λ Boo HR 8799. Initially, were uncertain mass due part to...
As a part of our ongoing Volume-limited A-Star (VAST) adaptive optics survey, we have obtained observations 26 binary systems with projected separations <100 AU, 13 which sufficient historical measurements to allow for refinement their orbital elements. For each system an estimated orbit, the dynamical mass was compared from mass-magnitude relations. Discrepancies between and theoretical can be explained by presence previously unresolved spectroscopic component, or non-solar metallicity...
Abstract We present the second data release (DR2) of SkyMapper Southern Survey, a hemispheric survey carried out with Telescope at Siding Spring Observatory in Australia, using six optical filters: u, v, g, r, i, z . DR2 is first to go beyond $\sim\!18$ mag (10 $\sigma$ ) limit Shallow Survey released (DR1), and includes portions sky full depth that reach $>\!21$ g r filters. The photometry has precision as measured by internal reproducibility 1% u v , 0.7% griz More than 21 000 $\deg^2$...
The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in new era multi-messenger astronomy. In this paper, we present event GW170817 and its SSS17a/DLT17ck (IAU label AT2017gfo) 14 Australian telescopes partner observatories as part Australian-based Australian-led research programs. We report early- late-time multi-wavelength observations, including optical imaging spectroscopy,...
Far-red spectra and VRIJHK photometry have been obtained for a sample of late-M dwarfs selected on the basis large reduced red magnitudes from LHS Catalog. Half stars in three faintest 1 mag bins are stars, other metallic-hydride subdwarfs. Relations between various colors investigated. Of all I - K most reliably correlates with spectral type. FeH bands near 9900 A clearly seen dwarf later than M5. Two cooler VB10, similar temperature to LHS2924 identified; both H-alpha emission appear...
UBVRI Hα CCD photometry has been obtained for the young open cluster NGC 2264. Using (R -Hα) color, a measure of emission, we selected member stars in pre-main-sequence (PMS) stage. The reliability color as PMS star selection criterion was critically evaluated from their spatial distribution, near-IR photometric data and spectroscopic characteristics. By constructing HR diagram, determined typical age spread Some discussions on discrepancy between turn-off turn-on were made. shape initial...
view Abstract Citations (368) References (54) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Long-period variables in the Magellanic Clouds : Supergiants, AGB stars, Supernova precursors, Planetary nebula and enrichment of interstellar medium. Wood, P. R. ; Bessell, M. S. Fox, W. IR JHK magnitudes low dispersion red spectra for 90 long period (LPVs) show LPVs to fall into distinct groups core He or C burning supergiants asymptotic giant branch (AGB) stars....
With an adaptive optics imaging survey of 148 B6–A7 stars, we have tested the hypothesis that unresolved lower mass companions are source unexpected X-ray detections stars in this spectral type range. The sample is composed 63 detected X-rays within ROSAT All Sky Survey and 85 form a control sample; both subsets same restricted distribution type, age, sensitivity separation coverage. A total 68 companion candidates resolved with separations ranging from 0.3 to 26.2 arcsec, 23 new detections....
A recent high-resolution H I survey of the Large Magellanic Cloud (LMC) shows that structure neutral atomic interstellar gas is dominated by numerous shells and holes, as well complex filamentary spiral-type structure. We present an up-to-date catalog candidate supergiant giant in LMC. The candidates are visually selected from data cube using selection classification criteria described. Twenty-three shells, defined those regions whose extent much larger than scale height, cataloged; 103...
We report deep imaging observations of the young, nearby star AB Pic, a member large Tucana-Horologium as sociation. have detected faint, red source 5.5" South with JHK colors compatible that young substellar L dwarf. Follow-up at two additional epochs confirm, confidence level 4.7sigma, faint object is companion to Pic rather than it being stationary background object. A low resolution K-band spectrum indicates an early-L spectral type for companion. Finally, evolutionary model predictions...
From radio to X-ray wavelengths, AB Doradus has been an intensively studied star. We have identified ~30 nearby star systems, each with one or more characteristics of youth, that are moving through space together Dor. This diverse set ~50 million year old systems is the comoving, youthful group closest Earth. The group's nucleus a clustering dozen stars ~20 pc from Earth includes Dor itself. joins previously known and somewhat younger distant Tucana/Horologium TW Hydrae associations β...