Ronald L. Gilliland
A5083219373- 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
- CCD and CMOS Imaging Sensors
- Solar and Space Plasma Dynamics
- Adaptive optics and wavefront sensing
- History and Developments in Astronomy
- Astrophysical Phenomena and Observations
- Space Exploration and Technology
- Calibration and Measurement Techniques
- Atmospheric Ozone and Climate
- Astronomical and nuclear sciences
- Infrared Target Detection Methodologies
- Photocathodes and Microchannel Plates
- Pulsars and Gravitational Waves Research
- Galaxies: Formation, Evolution, Phenomena
- Geophysics and Gravity Measurements
- Atomic and Subatomic Physics Research
- Spectroscopy and Laser Applications
- Scientific Research and Discoveries
- Planetary Science and Exploration
- Advanced MRI Techniques and Applications
Space Telescope Science Institute
2009-2020
Pennsylvania State University
2012-2020
Search for Extraterrestrial Intelligence
2014
Bay Area Environmental Research Institute
2014
University of California, Berkeley
1980-2014
Ames Research Center
2014
Northwestern University
2014
High Altitude Observatory
1980-2008
NSF National Center for Atmospheric Research
1980-2008
Purple Mountain Observatory
2007
The Kepler mission was designed to determine the frequency of Earth-sized planets in and near habitable zone Sun-like stars. is region where planetary temperatures are suitable for water exist on a planet's surface. During first 6 weeks observations, monitored 156,000 stars, five new exoplanets with sizes between 0.37 1.6 Jupiter radii orbital periods from 3.2 4.9 days were discovered. density Neptune-sized Kepler-4b similar that Neptune GJ 436b, even though irradiation level 800,000 times...
We report high-precision spectrophotometric observations of four planetary transits HD 209458, in the region sodium resonance doublet at 589.3 nm. find that photometric dimming during transit a bandpass centered on feature is deeper by (2.32 ± 0.57) × 10-4 relative to simultaneous adjacent bands. interpret this additional as absorption from atmosphere, recently predicted several theoretical modeling efforts. Our model for cloudless atmosphere with solar abundance atomic form predicts more...
On 2011 February 1 the Kepler mission released data for 156,453 stars observed from beginning of science observations on 2009 May 2 through September 16. There are 1235 planetary candidates with transit-like signatures detected in this period. These associated 997 host stars. Distributions characteristics separated into five class sizes: 68 approximately Earth-size (Rp < 1.25 R⊕), 288 super-Earth-size (1.25 R⊕ ⩽ Rp 662 Neptune-size (2 6 165 Jupiter-size (6 15 and 19 up to twice size Jupiter...
We present the photometric calibration of HST Advanced Camera for Surveys (ACS). give here an overview performance and 2 CCD cameras, Wide Field Channel (WFC) High Resolution (HRC), a description best techniques reducing ACS data. On-orbit observations spectrophotometric standard stars have been used to revise pre-launch estimate instrument response curves match predicted observed count rates. Synthetic photometry has determine zeropoints all filters in 3 magnitude systems derive...
The Hubble Deep Field (HDF) is a Director's Discretionary program on HST in Cycle 5 to image an undistinguished field at high Galactic latitude four passbands as deeply reasonably possible. These images provide the most detailed view date of distant galaxies and are likely be important for wide range studies galaxy evolution cosmology. In order optimize observing time available, northern continuous viewing zone was selected were taken ten consecutive days, or approximately 150 orbits....
We present photometric observations of an apparent Type Ia supernova (SN Ia) at a redshift ~1.7, the farthest SN observed to date. The supernova, 1997ff, was discovered in repeat observation by Hubble Space Telescope (HST) Deep Field-North (HDF-N) and serendipitously monitored with NICMOS on HST throughout Thompson et al. Guaranteed-Time Observer (GTO) campaign. type can be determined from host galaxy type: evolved, red elliptical lacking enough recent star formation provide significant...
New transiting planet candidates are identified in 16 months (2009 May-2010 September) of data from the Kepler spacecraft.Nearly 5000 periodic transit-like signals vetted against astrophysical and instrumental false positives yielding 1108 viable new candidates, bringing total count up to over 2300.Improved vetting metrics employed, contributing higher catalog reliability.Most notable is noise-weighted robust averaging multiquarter photo-center offsets derived difference image analysis that...
The Kepler Mission, launched on 2009 March 6, was designed with the explicit capability to detect Earth-size planets in habitable zone of solar-like stars using transit photometry method. Results from just 43 days data along ground-based follow-up observations have identified five new transiting measurements their masses, radii, and orbital periods. Many aspects stellar astrophysics also benefit unique, precise, extended, nearly continuous set for a large number variety stars. Early results...
We report the distribution of planets as a function planet radius (R_p), orbital period (P), and stellar effective temperature (Teff) for P < 50 day orbits around GK stars. These results are based on 1,235 (formally "planet candidates") from Kepler mission that include nearly complete set detected small 2 Earth radii (Re). For each 156,000 target stars we assess detectability R_p P. also correct geometric probability transit, R*/a. consider first within "solar subset" having Teff = 4100-6100...
We have coordinated Hubble Space Telescope (HST) photometry with ground-based discovery for three supernovae: Type Ia supernovae near z ≈ 0.5 (SN 1997ce, SN 1997cj) and a third event at = 0.97 1997ck). The superb spatial resolution of HST separates each supernova from its host galaxy leads to good precision in the light curves. use these curves relations between luminosity, light-curve shape, color calibrated low-z samples derive relative luminosity distances that are accurate 10% 20% 1....
The Kepler Mission Science Operations Center (SOC) performs several critical functions including managing the ~156,000 target stars, associated tables, science data compression tables and parameters, as well processing raw photometric downlinked from spacecraft each month. are first calibrated at pixel level to correct for bias, smear induced by a shutterless readout, other detector electronic effects. A background sky flux is estimated ~4500 pixels on of 84 CCD readout channels, simple...
We have observed four transits of the planet HD 209458 using STIS spectrograph on Hubble Space Telescope (HST). Summing recorded counts over wavelength between 582 and 638 nm yields a photometric time series with 80 s sampling relative precision about 1.1 × 10-4 per sample. The folded light curve can be fitted within observational errors model consisting an opaque circular transiting limb-darkened stellar disk. In this way we estimate planetary radius Rp = 1.347 ± 0.060 RJup, orbital...
view Abstract Citations (491) References (31) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Detection of Possible p-Mode Oscillations on Procyon Brown, Timothy M. ; Gilliland, Ronald L. Noyes, Robert W. Ramsey, Lawrence In the course a search for solar-like oscillations in bright late-type stars, Doppler variability was observed F5 subgiant Procyon. The variations have frequencies within 1.1 mHz range centered at 0.9 mHz, and total rms amplitude that 2.5...
We present Spitzer Space Telescope infrared photometric time series of the transiting extrasolar planet system TrES-1. The data span a predicted secondary eclipse, corresponding to passage behind star. In both bands our observations, we detect flux decrement with timing, amplitude, and duration as by published parameters system. This signal represents first direct detection (i.e. observation photons emitted by) orbiting another observed eclipse depths (in units relative flux) are 0.00066 +/-...
The Kepler mission has discovered more than 2500 exoplanet candidates in the first two years of spacecraft data, with approximately 40% those candidate multi-planet systems. high rate multiplicity combined low identified false positives indicates that multiplanet systems contain very few positive signals due to other not gravitationally bound target star. False are and removed, leaving behind a residual population transiting expected have less 1%. We present sample 340 planetary 851 planets...
The nearby transiting planet HD 189733b was observed during three transits with the Advanced Camera for Surveys of Hubble Space Telescope in spectroscopic mode. resulting time-series 675 spectra covers 550–1050 nm range, a resolution element ∼8 nm, at extremely high accuracy (signal-to-noise ratio up to 10 000 50-nm intervals each individual spectrum). Using these data, we disentangle effects limb darkening, measurement systematics and spots on surface host star, calculate wavelength...
Exoplanetary transmission spectroscopy in the near-infrared using Hubble Space Telescope (HST) NICMOS is currently ambiguous because different observational groups claim results from same data, depending on their analysis methodologies. Spatial scanning with HST/WFC3 provides an opportunity to resolve this ambiguity. We here report WFC3 of giant planets HD 209458b and XO-1b transit, spatial mode for maximum photon-collecting efficiency. introduce technique that derives exoplanetary spectrum...
NASA's Kepler Mission uses transit photometry to determine the frequency of earth-size planets in or near habitable zone Sun-like stars. The mission reached a milestone toward meeting that goal: discovery its first rocky planet, Kepler-10b. Two distinct sets events were detected: 1) 152 +/- 4 ppm dimming lasting 1.811 0.024 hours with ephemeris T[BJD]=2454964.57375+N*0.837495 days and 2) 376 9 6.86 0.07 T[BJD]=2454971.6761+N*45.29485 days. Statistical tests on photometric pixel flux time...
Asteroseismology involves probing the interiors of stars and quantifying their global properties, such as radius age, through observationsof normal modes oscillation. The technical requirements for conducting asteroseismology include ultra-high precision measured in photometry parts per million, well nearly continuous time series over weeks to years, cadences rapid enough sample oscillations with periods shortas a few minutes. We report on results from first 43 days observations which unique...
We present Hubble Space Telescope optical and near-ultraviolet transmission spectra of the transiting hot-Jupiter HD189733b, taken with repaired Imaging Spectrograph (STIS) instrument. The resulting cover range 2900-5700 Ang reach per-exposure signal-to-noise levels greater than 11,000 within a 500 bandwidth. used time series obtained during two transit events to determine wavelength dependance planetary radius measure exoplanet's atmospheric spectrum for first over this range. Our...
The Kepler spacecraft is monitoring more than 150,000 stars for evidence of planets transiting those stars. We report the detection two Saturn-size that transit same Sun-like star, based on 7 months observations. Their 19.2- and 38.9-day periods are presently increasing decreasing at respective average rates 4 39 minutes per orbit; in addition, times inner body display an alternating variation smaller amplitude. These signatures characteristic gravitational interaction near a 2:1 orbital...