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Fragmented Comet 73P/Schwassmann-Wachmann 3
Graykowski, Ariel; Jewitt, David
Comet 73P/Schwassmann-Wachmann 3 has been observed to fragment on several occasions, yet the cause of its fragmentation remains poorly understood. We use previously unpublished archival Hubble Space Telescope data taken in 2006 to study the properties of the primary fragment, 73P-C, in order to constrain the potential fragmentation mechanisms. Cur…
Constraints on a Putative Planet Sculpting the V4046 Sagittarii Circumbinary Disk
Dong, Ruobing; Wilner, David J.; Andrews, Sean M. +3 more
We analyze the highest-resolution millimeter continuum and near-infrared (NIR) scattered-light images presented to date of the circumbinary disk orbiting V4046 Sgr, a ∼20-Myr-old actively accreting, close binary T Tauri star system located a mere 72.4 pc from Earth. We observed the disk with the Atacama Large Millimeter/submillimeter Array (ALMA) …
A Long-term Photometric Variability and Spectroscopic Study of Luminous Blue Variable AF And in M31
Joshi, Yogesh C.; Misra, Kuntal; Gangopadhyay, Anjasha +2 more
We present a photometric and spectroscopic analysis of the Hubble-Sandage variable star AF And in M31. The data have been taken under the Nainital Microlensing Survey during 1998-2002, and follow-up observations were carried out until 2011. During this period, photometric observations in Cousins R and I bands were obtained for 169 nights spanning …
Searching for Wide Companions and Identifying Circum(sub)stellar Disks through PSF Fitting of Spitzer/IRAC Archival Images
Kraus, Adam L.; Martinez, Raquel A.
Direct imaging surveys have discovered wide-orbit planetary-mass companions that challenge existing models of both star and planet formation, but their demographics remain poorly sampled. We have developed an automated binary companion point-spread function (PSF) fitting pipeline to take advantage of Spitzer's infrared sensitivity to planetary-mas…
The Case for a Large-scale Occultation Network
Rice, Malena; Laughlin, Gregory
We discuss the feasibility of and present initial designs and approximate cost estimates for a large (N ∼ 2000) network of small photometric telescopes that is purpose-built to monitor V ≲ 15 Gaia mission program stars for occultations by minor solar system bodies. The implementation of this network would permit measurement of the solar system’s t…
The Quadratic Programming Method for Extracting Emission Line Maps from Line-blended Narrowband Images
Mito, Hiroyuki; Nakada, Yoshikazu; Ueta, Toshiya +3 more
We present a method to separate blended line emission from a set of narrowband (NB) images whose distinct throughput profiles overlap with each other. This method, based on the principle of quadratic programming (QP), treats line blending as a linearly constrained quadratic optimization problem and finds the solution by imposing a condition that t…
Io’s Atmosphere Silhouetted by Jupiter Lyα
Feaga, L. M.; Roth, L.; Retherford, K. D. +4 more
We report results from a new technique for mapping Io’s SO2 vapor distribution. The Space Telescope Imaging Spectrograph (STIS) instrument on the Hubble Space Telescope observed Io during four Jupiter transit events to obtain medium resolution far-UV spectral images near the Lyα wavelength of 121.6 nm. Jupiter’s bright Lyα dayglow provi…
IRAS 09002-4732: A Laboratory for the Formation of Rich Stellar Clusters
Garmire, Gordon P.; Feigelson, Eric D.; Broos, Patrick S. +2 more
IRAS 09002-4732 is a poorly studied embedded cluster of stars in the Vela Molecular Ridge at a distance of 1.7 kpc. Deep observations with the Chandra X-ray Observatory, combined with existing optical and infrared surveys, produce a catalog of 441 probable pre-main-sequence members of the region. The stellar spatial distribution has two components…
Two Circumstellar Nebulae Discovered with the Wide-field Infrared Survey Explore and Their Massive Central Stars
Grebel, Eva K.; Castro, Norberto; Gvaramadze, Vasilii V. +1 more
We report the discovery of two mid-infrared nebulae in the northern hemisphere with the Wide-field Infrared Survey Explorer and the results of optical spectroscopy of their central stars, BD+60° 2668 (composed of two components, separated from each other by ≈3 arcsec) and ALS 19653, with the Calar Alto 3.5 m telescope and the Southern African Larg…
Observations of Red Giants with Suspected Massive Companions
Tokovinin, Andrei; Makarov, Valeri V.
Motivated by the existence of binary systems where a stellar-mass black hole is bound to a normal star, we selected four red giants with large radial velocity (RV) variation from the survey of Space Interferometry Mission (SIM) grid stars and monitored their RVs for several months. None turned out to contain a massive companion above 2.5 solar mas…