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A New Distortion Solution for NIRC2 on the Keck II Telescope
Ghez, A. M.; Anderson, J.; Lu, J. R. +3 more
We present a new geometric distortion model for the narrow-field mode of the near-infrared camera (NIRC2) fed by the adaptive optics system on the W. M. Keck II telescope. The adaptive optics system and NIRC2 camera were realigned on 2015 April 13. Observations of the crowded globular cluster, M53, were obtained before and after the realignment to…
Comparison of Hipparcos Trigonometric and Mount Wilson Spectroscopic Parallaxes for 90 Subgiants that Defined the Class in 1935
Majewski, Steven R.; Beaton, Rachael L.; Sandage, Allan
A history is given of the discovery between 1914 and 1935 of stars of intermediate luminosity between giants and dwarfs with spectral types between G0 to K3. The Mount Wilson spectroscopists identified about 90 such stars in their 1935 summary paper of spectroscopic absolute magnitudes for 4179 stars. Called “subgiants” by Strömberg, these 90 star…
Decontaminating Swift UVOT Grism Observations of Transient Sources
Suntzeff, Nicholas B.; Kuin, Paul; Brown, Peter J. +1 more
We present a new technique of decontaminating Swift Ultraviolet/Optical Telescope grism spectra for transient objects. We describe the template image requirements and image processing steps necessary to successfully implement the empirical decontamination technique. We demonstrate the accuracy of the flux and wavelength calibrations for decontamin…
New Gapless COS G140L Mode Proposed for Background-limited Far-UV Observations
Anderson, Scott F.; France, Kevin; Fleming, Brian +6 more
Here we describe the observation and calibration procedure for a new G140L observing mode for the Cosmic Origins Spectrograph (COS) on board the Hubble Space Telescope (HST). This mode, CENWAV = 800, is designed to move the far-UV band fully onto the Segment A detector, allowing for more efficient observation and analysis by simplifying calibratio…
Unique Spectroscopy and Imaging of Mars with the James Webb Space Telescope
Hartogh, Paul; Lellouch, Emmanuel; Fouchet, Thierry +12 more
In this paper, we summarize the main capabilities of the James Webb Space Telescope (JWST) for performing observations of Mars. The distinctive vantage point of JWST at the Sun-Earth Lagrange point (L2) will allow sampling the full observable disk, permitting the study of short-term phenomena, diurnal processes (across the east-west axis), and lat…
Estimating Distances from Parallaxes
Bailer-Jones, Coryn A. L.
Astrometric surveys such as Gaia and LSST will measure parallaxes for hundreds of millions of stars. Yet they will not measure a single distance. Rather, a distance must be estimated from a parallax. In this didactic article, I show that doing this is not trivial once the fractional parallax error is larger than about 20%, which will be the case f…
Revised Filter Profiles and Zero Points for Broadband Photometry
Mann, Andrew W.; von Braun, Kaspar
Estimating accurate bolometric fluxes for stars requires reliable photometry to absolutely flux calibrate the spectra. This is a significant problem for studies of very bright stars, which are generally saturated in modern photometric surveys. Instead we must rely on photometry with less precise calibration. We utilize precisely flux-calibrated sp…
Elemental Abundance Analyses with DAO Spectrograms. XXXVI. The Hot Metallic Line Stars Theta Leonis and Omicron Pegasi
Adelman, Saul J.; Gulliver, Austin F.; Heaton, Robert J.
A New Luminous Blue Variable in M31
Humphreys, Roberta M.; Gordon, Michael S.; Martin, John C.
Not Available
Based on observations with the Multiple Mirror Telescope, a joint facility of the Smithsonian Institution and the University of Arizona.Spectro-Imaging of the Asymmetric Inner Molecular and Dust Shell Region of the Mira Variable W Hya with MIDI/VLTI
Quirrenbach, A.; Lopez, B.; Kerschbaum, F. +4 more
Not Available
Based on observations made with the Very Large Telescope Interferometer (VLTI) at the Paranal Observatory under program IDs 083.D-0294, 084.D-0334, and 085.D-0201.