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Related papers: ASTRA: ASTrometry and phase-Referencing Astronomy …

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Gamma-ray astronomy is a branch whose potential has not yet been fully exploited. The observations of elemental and isotopic abundances in supernova (SN) explosions are key probes not only of the stellar structure and evolution but also for…

The Keck Planet Imager and Characterizer (KPIC) is an upgrade to the Keck II adaptive optics system enabling high contrast imaging and high-resolution spectroscopic characterization of giant exoplanets in the mid-infrared (2-5 microns). The…

High spectral-resolution Br-gamma VLTI/AMBER observations of classical Be stars reveal complex visibility, phase, and closure phase profiles, which were not seen in previous lower-resolution data. They present new challenges for the…

Solar and Stellar Astrophysics · Physics 2011-07-27 S. Stefl , T. Rivinius , D. Baade , A. Carciofi

A short review of recent results in long-baseline optical interferometry pertaining to fundamental stellar parameters and the future possibilities this area over the next decade. Included are discussions of accurate stellar masses, links…

Solar and Stellar Astrophysics · Physics 2009-05-12 J. P. Aufdenberg , S. T. Ridgway , R. J. White

Optical interferometry provides us with a unique opportunity to improve our understanding of stellar structure and evolution. Through direct observation of rotationally distorted photospheres at sub-milliarcsecond scales, we are now able to…

Solar and Stellar Astrophysics · Physics 2012-04-13 Gerard T. van Belle

The ASTRA Cassegrain Spectrophotometer and its automated 0.5-m telescope at Fairborn Observatory in Arizona will produce a large quantity of high precision stellar flux distributions. A separate paper (Adelman et al. 2007) presented a…

Astrophysics · Physics 2007-05-23 Barry Smalley , Austin F. Gulliver , Saul J. Adelman

Stellar activity interferes with precise radial velocity measurements and limits our ability to detect and characterize planets, particularly Earth-like planets. We introduce \aestra (Auto-Encoding STellar Radial-velocity and Activity), a…

Earth and Planetary Astrophysics · Physics 2023-12-01 Yan Liang , Joshua N. Winn , Peter Melchior

This year, a second generation of coronagraphs dedicated to high-contrast direct imaging of exoplanets is starting operations. Among them, SPHERE, installed at the focus of the UT3 Very Large Telescope, reaches unprecedented contrast ratios…

Instrumentation and Methods for Astrophysics · Physics 2015-10-22 H. Le Coroller , M. Nowak , L. Arnold , K. Dohlen , T. Fusco , J. F. Sauvage , A. Vigan

Lyman alpha emission presents a means of identifying very high redshift galaxies, provided such objects can be reliably distinguished from foreground emission-line galaxies. Here we report on a program of imaging and spectroscopic studies…

Astrophysics · Physics 2007-05-23 Esther M. Hu

Submillimeter observations are a key for answering many of the big questions in modern-day astrophysics, such as how stars and planets form, how galaxies evolve, and how material cycles through stars and the interstellar medium. With the…

Solar and Stellar Astrophysics · Physics 2019-08-13 Marco Padovani , Jes Jørgensen

We extend our previous demonstration of the first on-sky primary mirror segment closed-loop control on Keck using a vector-Zernike wavefront sensor (vZWFS), which improved the Strehl ratio on the NIRC2 science camera by up to 10 percentage…

The large surveys and sensitive instruments of modern astronomy are turning ever more examples of variable objects, many of which are extending the parameter space to testing theories of stellar evolution and accretion. Future projects such…

Astrophysics · Physics 2015-05-13 T. R. Marsh

The Constellation X-ray Mission is a high throughput X-ray facility emphasizing observations at high spectral resolution (E/\Delta E \sim 300-3000), and broad energy bandpass (0.25-40 keV). Constellation-X will provide a factor of nearly…

Astrophysics · Physics 2009-10-31 Azita Valinia , Nicholas White , Harvey Tananbaum , the Constellation-X Team

High Definition Astrometry (0.1 - 1.0 micro-arcseconds) will open a new window into neighboring planetary systems. For the first time, the realm of temperate terrestrial worlds will be explored. This includes Earth Analogs, thereby allowing…

Earth and Planetary Astrophysics · Physics 2019-05-21 Philip Horzempa

We simulate the observations of proper motion of stars very close to the Galactic Center. We show that the speckle interferometry done with the Keck II telescope is accurate enough to obtain orbital parameters for stars with the period P…

Astrophysics · Physics 2009-10-31 M. Jaroszynski

Here I review the current state of the field of optical stellar interferometry, concentrating on ground-based work although a brief report of space interferometry missions is included. We pause both to reflect on decades of immense progress…

Astrophysics · Physics 2009-11-10 John D. Monnier

We present the last results of our PSF reconstruction (PSF-R) project for the Keck-II and Gemini-North AO systems in natural guide star mode. Our initial tests have shown that the most critical aspects of PSF-R are the determination of the…

Instrumentation and Methods for Astrophysics · Physics 2012-02-21 Laurent Jolissaint , Chris Neyman , Julian Christou , Peter Wizinowich , Laurent Mugnier

In a few years astrometry with the venerable combination of Hubble Space Telescope and Fine Guidance Sensor will be replaced by SIM, GAIA, and long-baseline interferometry. Until then we remain a resource of choice for sub-millisecond of…

Astrophysics · Physics 2008-03-04 G. Fritz Benedict , Barbara E. McArthur , Jacob L. Bean