Search Publications
Yes, Multi-periodic Dwarfs in Upper Scorpius Are Binaries
Tokovinin, Andrei; Briceño, Cesar
We found that multi-periodic low-mass stars discovered by Kepler K2 in the Upper Scorpius association are close binaries with typical separations of the order of 10 au and large mass ratios. These stars were surveyed by speckle interferometry at the SOAR telescope with spatial resolution of 0.″04. Out of 129 observed targets, we resolved 70 pairs …
Observations contradict galaxy size and surface brightness predictions that are based on the expanding universe hypothesis
Lerner, Eric J.
In a non-expanding universe, surface brightness is independent of distance or redshift, while in an expanding universe it decreases rapidly with both. Similarly, for objects of the same luminosity, the angular radius of an object in a non-expanding universe declines with redshift, while in an expanding universe this radius increases for redshifts …
New member candidates of Upper Scorpius from Gaia DR1
Merín, B.; Riviere-Marichalar, P.; Wilkinson, S.
Context. Selecting a cluster in proper motion space is an established method for identifying members of a star-forming region. The first data release from Gaia (DR1) provides an extremely large and precise stellar catalogue, which when combined with the Tycho-2 catalogue gives the 2.5 million parallaxes and proper motions contained within the Tych…
On the icy edge at Louth and Korolev craters
Bapst, Jonathan; Byrne, Shane; Brown, Adrian J.
The modern climate of Mars has been well characterized from over a decade of orbiting spacecraft, in situ measurements via landers/rovers, and theoretical advances in climate modeling. Nonetheless, important questions remain unanswered, including the present-day mass balance of the north polar residual cap and its icy outliers. Exposed water-ice m…
Bias of damped Lyman-α systems from their cross-correlation with CMB lensing
Font-Ribera, A.; Slosar, A.; Alonso, D. +1 more
We cross-correlate the positions of damped Lyman-α systems (DLAs) and their parent quasar catalog with a convergence map derived from the Planck cosmic microwave background (CMB) temperature data. We make consistent measurements of the lensing signal of both samples in both Fourier and configuration space. By interpreting the excess signal present…
Optical Coronagraphic Spectroscopy of AU Mic: Evidence of Time Variable Colors?
Weinberger, Alycia J.; Debes, John H.; Donaldson, Jessica K. +4 more
We present coronagraphic long slit spectra of AU Mic’s debris disk taken with the STIS instrument aboard the Hubble Space Telescope. Our spectra are the first spatially-resolved, scattered light spectra of the system’s disk, which we detect at projected distances between approximately 10 and 45 au. Our spectra cover a wavelength range between 5200…
Physical Processes Involved in the EUV "Surge" Event of 9 May 2012
Démoulin, Pascal; Mandrini, Cristina H.; López Fuentes, Marcelo +4 more
We study an extreme ultraviolet (EUV) confined ejection observed on 9 May 2012 in Active Region (AR) NOAA 11476. For the analysis we use observations in multiple wavelengths (EUV, X-rays, Hα , and magnetograms) from a variety of ground- and space-based instruments. The magnetic configuration showed two rotating bipoles within the following polarit…
The Influence of Solar Wind and Geomagnetic Indices on Lower Band Chorus Emissions in the Inner Magnetosphere
Krasnoselskikh, V.; Walker, S. N.; Balikhin, M. A. +2 more
Statistical wave models, describing the distribution of wave amplitudes as a function of location, geomagnetic activity, and other parameters, are needed as the basis to describe the wave-particle interactions within numerical models of the radiation belts. In this study, we widen the scope of the statistical wave models by investigating which of …
A near-infrared variable star survey in the Magellanic Clouds: the Small Magellanic Cloud data
Nagata, Tetsuya; Tamura, Motohide; Matsunaga, Noriyuki +12 more
A very long-term near-infrared variable star survey towards the Large and Small Magellanic Clouds (LMC and SMC) was carried out using the 1.4 m InfraRed Survey Facility at the South African Astronomical Observatory. This project was initiated in 2000 December in the LMC, and in 2001 July in the SMC. Since then an area of 3 deg2 along th…
Onboard Automated CME Detection Algorithm for the Visible Emission Line Coronagraph on ADITYA-L1
Pant, Vaibhav; Banerjee, Dipankar; Sankarasubramanian, K. +3 more
ADITYA-L1 is India's first space mission to study the Sun from the Lagrange 1 position. The Visible Emission Line Coronagraph (VELC) is one of seven payloads on the ADITYA-L1 mission, which is scheduled to be launched around 2020. One of the primary objectives of the VELC is to study the dynamics of coronal mass ejections (CMEs) in the inner coron…