Search Publications
The mid-infrared diameter of W Hydrae
Quirrenbach, A.; Lopez, B.; Leinert, C. +2 more
Aims: Asymptotic giant branch (AGB) stars are among the largest distributors of dust into the interstellar medium, and it is therefore important to understand the dust formation process and sequence in their strongly pulsating extended atmosphere. By monitoring the AGB star W Hya interferometrically over a few pulsations cycles, the upper atm…
The globular cluster systems of Abell 1185
Côté, P.; Blakeslee, J. P.; Jordán, A. +4 more
We examine the properties of a previously discovered population of globular clusters in the heart of the rich galaxy cluster Abell 1185 that might be intergalactic in nature. Deep images obtained with the Advanced Camera for Surveys (ACS) aboard Hubble Space Telescope (HST) confirm the presence of ~1300 globular clusters brighter than IF814W<…
Newly Identified Properties of Surface Acoustic Power
Braun, D. C.; Schunker, H.
The cause of enhanced acoustic power surrounding active regions, known as the acoustic halo, is not as yet understood. We explore the properties of the enhanced acoustic power observed near disk center from 21 to 27 January 2002, including AR 9787. We find that i) there exists a strong correlation of the enhanced high-frequency power with magnetic…
Clues to the Star Formation in NGC 346 across Time and Space
Panagia, Nino; Sabbi, Elena; De Marchi, Guido
We have studied the properties of the stellar populations in the field of the NGC 346 cluster in the Small Magellanic Cloud, using the results of a novel self-consistent method that provides a reliable identification of pre-main sequence (PMS) objects actively undergoing mass accretion, regardless of their age. The 680 identified bona fide PMS sta…
Post-equinox observations of Uranus: Berg's evolution, vertical structure, and track towards the equator
de Pater, Imke; Sromovsky, L. A.; Fry, P. M. +5 more
We present observations of Uranus taken with the near-infrared camera NIRC2 on the 10-m W.M. Keck II telescope, the Wide Field Planetary Camera 2 (WFPC2) and the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) from July 2007 through November 2009. In this paper we focus on a bright southern feature, referred to as the "Berg." In Sro…
Long-term Evolution of Magnetic and Dynamical Properties in A Sunspot Light Bridge
Shimizu, Toshifumi
Sunspot light bridges (LBs)—long bright lanes appearing in umbra—sometimes show dynamical behaviors such as plasma ejections, brightenings, and fast gas flows in the photosphere and lower chromosphere, but we have not understood what causes these dynamics. The Hinode Solar Optical Telescope successfully captured the entire period of the evolution …
Cluster observations of a cusp diamagnetic cavity: Structure, size, and dynamics
Adamson, E.; Otto, A.; Nykyri, K. +2 more
We have analyzed Cluster magnetic field and plasma data during high-altitude cusp crossing and compared them with high-resolution MHD simulations. Cluster encountered a diamagnetic cavity (DMC) during northward interplanetary magnetic field (IMF) conditions, and as the IMF rotated southward, the spacecraft reencountered the cavity more at the sunw…
Electromagnetic ion cyclotron waves in the helium branch induced by multiple electromagnetic ion cyclotron triggered emissions
Dandouras, Iannis; Omura, Yoshiharu; Shoji, Masafumi +3 more
Electromagnetic ion cyclotron (EMIC) triggered emissions with rising tones between the H+ and He+ cyclotron frequencies were found in the inner magnetosphere by the recent Cluster observations. Another type of EMIC wave with a constant frequency is occasionally observed below the He+ cyclotron frequency after the m…
Properties of the H II Region Populations of M51 and NGC 4449 from Hα Images with the Advanced Camera for Surveys on the Hubble Space Telescope
Beckman, John E.; Gutiérrez, Leonel; Buenrostro, Valeria
We have used images from the Advanced Camera for Surveys on the Hubble Space Telescope in Hα, and in the neighboring continuum, to produce flux-calibrated images of the large spiral galaxy M51 and the dwarf irregular NGC 4449. From these images, we have derived the absolute luminosities in Hα, the areas, and the positions with respect to the galac…
IGR J17361-4441: a possible new accreting X-ray binary in NGC 6388
Rodriguez, J.; Ferrigno, C.; Papitto, A. +7 more
IGR J17361-4441 is a newly discovered INTEGRAL hard X-ray transient, located in the globular cluster NGC 6388. We report here the results of the X-ray and radio observations performed with Swift, INTEGRAL, RXTE, and the Australia Telescope Compact Array (ATCA) after the discovery of the source on 2011 August 11. In the X-ray domain, IGR J17361-444…