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The Deepest Supernova Search is Realized in the Hubble Ultra Deep Field Survey
Riess, Adam G.; Strolger, Louis-Gregory
The Hubble Ultra Deep Field Survey has provided the deepest optical and near-infrared views of the universe yet, and has enabled a search for the most distant supernovae, to z~2.2. We have found four supernovae by searching spans of integrations of the Ultra Deep Field and the Ultra Deep Field Parallels taken with the Hubble Space Telescope paired…
Observations of the coronal dynamics associated with solar radio spike burst emission
Aurass, H.; Khan, J. I.
We present the results of an analysis of multi-wavelength data for a solar radio spike burst event which was observed on 1997 November 14 by the Solar Radio Spectrometers of the Astrophysikalisches Institut Potsdam (AIP). Using radio imaging data from the Nançay Radioheliograph we are able to determine the location of the spike burst emission site…
From the Sun to the Earth: impact of the 27-28 May 2003 solar events on the magnetosphere, ionosphere and thermosphere
Auchère, F.; Bocchialini, K.; Cornilleau-Wehrlin, N. +10 more
During the last week of May 2003, the solar active region AR 10365 produced a large number of flares, several of which were accompanied by Coronal Mass Ejections (CME). Specifically on 27 and 28 May three halo CMEs were observed which had a significant impact on geospace. On 29 May, upon their arrival at the L1 point, in front of the Earth's magne…
uvby - β Photoelectric Photometry of the Open Cluster α Per
Sareyan, J. -P.; Peña, J. H.
Absolute photoelectric photometry of stars in the direction of the Open Cluster α Per has been secured and is presented along with an analysis reinforced with all the available data in Strömgren uvby-β photometry compiled from the literature. Cluster membership is analyzed and the physical characteristics of the stars have been deduced. The member…
The Discovery of a P Cygni Analog in M31
Massey, Philip
We present spectroscopy and discuss the photometric history of a previously obscure star in M31. The spectrum of the star is an extremely close match to that of P Cygni, one of the archetypes of luminous blue variables (LBVs). The star has not shown much variability over the past 40 years (<0.2 mag), although small-scale (0.05 mag) variations o…
The Seismic Correlation Signature of Moderate-Scale Flow in the Sun
Woodard, M. F.
Flows in the solar convection zone introduce correlation between distinct horizontal-wavevector and frequency components of wave motion in the Sun. We derive expressions for the linear sensitivity of helioseismic correlation data to subphotospheric supergranular-scale flow, for use in helioseismic inversions. The sensitivity calculations are based…
Alfvén waves in the near-PSBL lobe: Cluster observations
Balogh, A.; Zhang, T. L.; Klecker, B. +14 more
Electromagnetic low-frequency waves in the magnetotail lobe close to the PSBL (Plasma Sheet Boundary Layer) are studied using the Cluster spacecraft. The lobe waves show Alfvénic properties and transport their wave energy (Poynting flux) on average toward the Earth along magnetic field lines. Most of the wave events are rich with oxygen (O+
Distribution of extinction and star formation in NGC 1569
Battaner, E.; Relaño, M.; Lisenfeld, U. +1 more
We investigate the spatial distribution of the intrinsic extinction in the starburst dwarf galaxy NGC 1569 using an extinction map of the whole galaxy derived from the mbox H α/ mbox H β emission line ratio. We differentiate the extinction in the H ii regions from the extinction of the diffuse gas. The intrinsic extinction shows considerable varia…
WLM-1: An old, Nonrotating, Gravitationally Unperturbed, Highly Elliptical Extragalactic Globular Cluster
Stephens, Andrew W.; Catelan, Márcio; Contreras, Roxana P.
Globular clusters have long been known for presenting (at times) significant deviations from spherical symmetry. While rotation has been the main proposed explanation, other complicating factors such as their constant interaction with the strong gravitational potential of their host galaxy have made it difficult for a consensus to be reached. To a…
Subsurface characteristics of sunspots
Kosovichev, Alexander G.
Time distance helioseismology provides 3-D subphotospheric maps of sunspots, emerging magnetic structures and associated convective flows. This gives us new insights into the basic physical processes inside the Sun, formation of magnetic structures in the solar plasma and mechanisms of solar activity. Recent results from the MDI instrument on SOHO…