Search Publications
Precise Orbit Determination of MEX Flyby Phobos Using Simulated Radiometric and Image Data
Yan, Jianguo; Gao, Wutong; Zhu, Xinbo +3 more
Turning Instrument Background Into Science Data for Structural Features of Radiation Belts
Dandouras, I.; Rème, H.; Liemohn, M. W. +2 more
Approaches regarding how to turn the instrument background counts into scientifically valuable data are presented in this Technical Report on Methods. The background counts due to penetrating energetic particles of radiation belts detected on Cluster CIS HIA and CODIF instruments and the Double Star HIA instrument are used in these approaches. In …
Spectral energy distribution similarity of the local galaxies and the 3.6 µm selected galaxies from the Spitzer Extended Deep Survey
Cheng, Cheng; Li, Zi-Jian; Huang, Jia-Sheng +11 more
The Spitzer Extended Deep Survey (SEDS) as a deep and wide mid-infrared (MIR) survey project provides a sample of 500 000+ sources spreading 1.46 square degree and a depth of 26 AB mag (3σ). Combining with the previous available data, we build a PSF-matched multi-wavelength photometry catalog from u band to 8 µm. We fit the SEDS galaxies spe…
Properties of the recently discovered Eclipsing Binary GSC 03421-01402
Lloyd, Ch.; Screech, J.
GSC 03421-01402 is a low-amplitude eclipsing binary with a period of 7.6800475(44) d. The eclipsing binary is one component of a close pair identified in the Gaia EDR3 data with delta G = 0.45 mag. The light-curve suggests that the primary eclipse is total with an observed depth of 0.13 mag, but due to dilution the true depth could be approximatel…
The Plasmasphere: Its Interactions and Dynamics
Darrouzet, Fabien; Gallagher, Dennis L.; De Keyser, Johan
Magnetic activity and age estimation of red giants using neural networks
Lu, Hong-peng; Zhang, Li-yun; Karoff, Christoffer
In this work, we analysed the magnetic activity of 5349 Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) low-dispersion spectra of 3539 red giants by calculating equivalent width (EW) of magnetic activity lines (H α, H β, H γ, H δ, $\rm{Ca~{ii} H\&K}$, $\rm{Ca~{ii} IRT}$). Combining LAMOST spectral parameters, asteroseismic p…
UV photometry of spotted stars in the horizontal branch of the globular cluster NGC 2808 using AstroSat
Sahu, Snehalata; Subramaniam, Annapurni; Prabhu, Deepthi S.
A recent study of hot (20,000 to 30,000 K) extreme horizontal branch (EHB) stars in globular clusters (GCs) has led to the discovery of their variability. It is suggested that this variability is driven by the projected rotation of magnetic spots on the stellar surfaces and is expected to have higher amplitudes at shorter wavelengths. Here, we pre…
Trigonometric Parallaxes of Two T Dwarfs With Keck and ShaneAO Astrometry
Lu, Jessica R.; Ammons, S. Mark; Nguyen, Jayke +4 more
We present trigonometric parallax and proper motion measurements for two T-type brown dwarfs. We derive our measurements from infrared laser guide star adaptive optics observations spanning five years from the ShaneAO/SHARCS and NIRC2/medium-cam instruments on the Shane and Keck telescopes, respectively. To improve our astrometric precision, we me…
Determinación de los parámetros H y G para 4000 asteroides del catálogo Gaia DR2
Duffard, R.; Colazo, M.; Weidmann, W.
The Gaia mission will provide the scientific community with high- quality observations of ∼ 300,000 asteroids of all categories. The purpose of this work is to obtain a catalog of phase function parameters (H and G) for all the asteroids that are observed by the Gaia mission and which were published in the DR2 catalogue. For this purpose, we intro…
UVIT observation of Milky Way satellite galaxy Reticulum II
Thirupathi, Sivarani; Divakar, Devika K.; Doddamani, Vijayakumar H.
We present the UV photometry of one of the Ultra-Faint Dwarf (UFD) Milky Way (MW) satellite galaxies, Reticulum II, using images acquired with the Ultra-Violet Imaging Telescope (UVIT) onboard AstroSat. Reticulum II is a dark matter dominated, one of the most metal-poor and old (13.5 Gyr) satellite galaxies. High resolution spectroscopy of red gia…