Search Publications

Evolution of the cloud field and wind structure of Jupiter's highest speed jet during a huge disturbance
DOI: 10.1051/0004-6361/200912282 Bibcode: 2009A&A...507..513B

Sánchez-Lavega, A.; García-Melendo, E.; Pérez-Hoyos, S. +1 more

Aims: Despite the banded visual aspect of cloud patterns in Jupiter, high resolution images indicate that these regions are markedly turbulent. One region of particular interest is the north temperate belt (NTB) at 21° N planetocentric latitude, where the most intense Jovian jet resides with eastward peak speeds of 160-180 m s-1. Almost…

2009 Astronomy and Astrophysics
eHST 9
No first ionization potential fractionation in the active stars AR Piscium and AY Ceti
DOI: 10.1051/0004-6361/200912069 Bibcode: 2009A&A...505..299S

Sanz-Forcada, J.; Micela, G.; Affer, L.

Context: The comparison of coronal and photospheric abundances in cool stars is an essential question to resolve. In the Sun an enhancement of the elements with low first ionization potential (FIP) is observed in the corona with respect to the photosphere. Stars with high levels of activity seem to show a depletion of elements with low FIP when co…

2009 Astronomy and Astrophysics
XMM-Newton 9
Water masers in the Saturnian system
DOI: 10.1051/0004-6361:200811186 Bibcode: 2009A&A...494L...1P

Gurvits, L. I.; Pogrebenko, S. V.; Mujunen, A. +11 more

Context: The presence of water has long been seen as a key condition for life in planetary environments. The Cassini spacecraft discovered water vapour in the Saturnian system by detecting absorption of UV emission from a background star. Investigating other possible manifestations of water is essential, one of which, provided physical conditions …

2009 Astronomy and Astrophysics
Cassini 9
The ultraviolet flare at the center of the elliptical galaxy NGC 4278
DOI: 10.1051/0004-6361/200913046 Bibcode: 2009A&A...508..641C

Morelli, L.; Buson, L. M.; Beifiori, A. +5 more

Context: A large fraction of otherwise normal galaxies shows a weak nuclear activity. One of the signatures of the low-luminosity active galactic nuclei (LLAGNs) is ultraviolet variability which was serendipitously discovered in the center of some low-ionization nuclear emission-line region (LINER) galaxies.
Aims: There is a pressing need to a…

2009 Astronomy and Astrophysics
eHST 9
Large-scale horizontal flows in the solar photosphere. V. Possible evidence for the disconnection of bipolar sunspot groups from their magnetic roots
DOI: 10.1051/0004-6361/200912422 Bibcode: 2009A&A...506..875S

Švanda, M.; Sobotka, M.; Klvaňa, M.

In a recent paper (Švanda et al. 2008, A&A, 477, 285) we pointed out that, based on the tracking of Doppler features in the full-disc MDI Dopplergrams, the active regions display two dynamically different regimes. We speculated that this could be a manifestation of the sudden change in the active regions dynamics, caused by the dynamic disconn…

2009 Astronomy and Astrophysics
SOHO 8
On the morphology of the compact dust shell in the symbiotic system HM Sagittae
DOI: 10.1051/0004-6361:200810934 Bibcode: 2009A&A...493.1043S

Chesneau, O.; Sacuto, S.

Context: The symbiotic system HM Sagittae consists of a Mira star and a secondary White Dwarf component. The dust content of the system was severely affected by the nova outburst in 1975, which is still ongoing. The capabilities of optical interferometry operating in the mid-IR allow us to investigate the current geometry of the…

2009 Astronomy and Astrophysics
ISO 8
Orientations of very faint galaxies in the Coma cluster
DOI: 10.1051/0004-6361:200810535 Bibcode: 2009A&A...493..399A

Ilbert, O.; Pelló, R.; Adami, C. +5 more

Context: Models of large scale structure formation predict the existence of preferential orientations for galaxies in clusters.
Aims: We have searched for preferential orientations of very faint galaxies in the Coma cluster (down I_Vega ∼-11.5).
Methods: By applying a deconvolution method to deep u* and I band images of the Coma…

2009 Astronomy and Astrophysics
eHST 8
Adapting Marchal's test of escape to real triple stars
DOI: 10.1051/0004-6361/200809392 Bibcode: 2009A&A...504..277L

Li, P. J.; Fu, Y. N.; Sun, Y. S.

Context: For a general N-body system, Marchal constructed an analytical test of escape, which uses only a one-dimensional projected motion state of the system at any given instant. This test is well adapted to identifying real, disintegrating small stellar systems, of which the full motion states are generally unavailable. However, to our knowledg…

2009 Astronomy and Astrophysics
Hipparcos 7
Morphological and dynamical properties of small-scale chromospheric features deduced from IBIS observations
DOI: 10.1051/0004-6361/200912517 Bibcode: 2009A&A...507.1625C

Romano, P.; Spadaro, D.; Contarino, L. +2 more

Context: In the past, chromospheric features were mostly studied by analyzing observations performed along the Hα profile, but several aspects related to their formation and dynamics remained uncertain and poorly understood. Recently, new investigations have been carried out using data obtained along the Ca II line at 854.21 nm, providing new inpu…

2009 Astronomy and Astrophysics
SOHO 7
The physical conditions in Gomez's Hamburger (IRAS 18059-3211), a pre-MS rotating disk
DOI: 10.1051/0004-6361/200811233 Bibcode: 2009A&A...500.1077B

Bujarrabal, V.; Young, K.; Castro-Carrizo, A.

Aims: We aim to study the structure, dynamics, and physical conditions of Gomez's Hamburger (IRAS 18059-3211; GoHam), and in particular confirm that GoHam mainly consists of a flaring disk in Keplerian rotation around a young, probably pre-MS star.
Methods: We present high resolution SMA maps of 12CO J = 2-1, 13CO J = 2-1…

2009 Astronomy and Astrophysics
eHST 7