Search Publications
The Nature of Overluminous F Stars Observed in a Radial-Velocity Survey
Suchkov, A. A.; Griffin, R. F.
We have conducted a radial-velocity survey of bright (V<9), overluminous, F stars within 80 pc. The criterion of overluminosity is ΔMc0=Mc0-MV>=0.5, where MV is the absolute magnitude based on the Hipparcos parallax and Mc0 is the absolute magnitude from …
The Virgo High-Resolution CO Survey: III. NGC 4254
Nakanishi, Hiroyuki; Koda, Jin; Sofue, Yoshiaki +1 more
We present high-angular-resolution (1''.5 - 5'') interferometer observations of the 12CO (J = 1--0) line emission in the central region of the SA(s)c galaxy NGC 4254 (M 99). The observations were obtained using the Nobeyama Millimeter-wave Array (NMA) during the course of a long-term CO-line survey of Virgo spirals. We present the spect…
A study of the propagation of electromagnetic waves in Titan's atmosphere with the TLM numerical method
Morente, Juan A.; Portí, Jorge A.; Besser, Bruno P. +2 more
A numerical modeling of the electromagnetic characteristics of Titan's atmosphere is carried out by means of the TLM numerical method, with the aim of calculating the Schumann resonant frequencies of Saturn's satellite. The detection and measurement of these resonances by the Huygens probe, which will enter Titan's atmosphere at the beginning of 2…
Hard x-ray Pulsations in the Initial Phase of Flares
Karlický, M.; Fárník, F.; Švestka, Z.
When analyzing light curves of hard X-ray bursts recorded by the Hard X-Ray Spectrometer on board the MTI satellite, we have found three events (all associated with major solar flares, two of them in the same active region) which show pulsations in the very initial phase of the burst. Periods of the pulsations range from 25 to 48 s. We compare the…
How did the solar wind structure change around the solar maximum? From interplanetary scintillation observation
McComas, D. J.; Elliott, H. A.; Tokumaru, M. +5 more
Observations from the second Ulysses fast latitude scan show that the global structure of solar wind near solar maximum is much more complex than at solar minimum. Soon after solar maximum, Ulysses observed a polar coronal hole (high speed) plasma with magnetic polarity of the new solar cycle in the Northern Hemisphere. We analyze the solar wind s…
IBIS preliminary results on Cygnus X-1 spectral and temporal characteristics
Goldoni, P.; Di Cocco, G.; Malaguti, G. +11 more
We report preliminary results of a broadband spectral and temporal study of the black-hole binary Cyg X-1 performed with the IBIS telescope. Cyg X-1 was the first pointed celestial target of IBIS during the INTEGRAL Performance and Verification Phase, 2002 Nov.-Dec., for a total observing time of ~ 2 Ms in both staring and dithering mode. Here, we…
Dynamical Masses of Young Stars in Multiple Systems
Nelan, E.; Schaefer, G. H.; Simon, M. +1 more
We present recent measurements of the orbital motion in the young binaries DF Tau and ZZ Tau and the hierarchical triple Elias 12 that were obtained with the Fine Guidance Sensors on the Hubble Space Telescope and at the Keck Observatory using adaptive optics. Combining these observations with previous measurements from the literature, we compute …
The nature of Neptune's increasing brightness: evidence for a seasonal response *
Baines, K. H.; Sromovsky, L. A.; Fry, P. M. +1 more
Hubble Space Telescope (HST) observations in August 2002 show that Neptune's disk-averaged reflectivity increased significantly since 1996, by 3.2 ± 0.3% at 467 nm, 5.6 ± 0.6% at 673 nm, and 40 ± 4% in the 850-1000 nm band, which mainly results from dramatic brightness increases in restricted latitude bands. When 467-nm HST observations from 1994 …
Stellar content of NGC 404 - The nearest S0 Galaxy
Tikhonov, N. A.; Galazutdinova, O. A.; Aparicio, A.
We report V -band and I -band CCD stellar and surface photometry of the galaxy NGC 404 , taken with HST WFPC2 and the 2.5 m Nordic telescope. The colour-magnitude diagram for the stars in this galaxy is typical of that of spheroidal systems (i.e. it lacks luminous, young stars but contains a large number of Asymptotic Giant Branch (AGB) and Red Gi…
The dynamics of the nebula M1-67 around the run-away Wolf-Rayet star WR 124
Lamers, H. J. G. L. M.; van der Sluys, M. V.
A new point of view on the dynamics of the circumstellar nebula M1-67 around the run-away Wolf-Rayet (WR) star WR 124 is presented. We simulated the outbursts of nebulae with different morphologies, to compare the results to the observed dynamical spectra of M1-67. We found that it has been interacting with the surrounding ISM and has formed a bow…