Search Publications
On the Evolution of a Sub-C Class Flare: A Showcase for the Capabilities of the Revamped Catania Solar Telescope
Spadaro, Daniele; Guglielmino, Salvo L.; Romano, Paolo +9 more
Solar flares are occasionally responsible for severe space-weather events, which can affect space-borne and ground-based infrastructures, endangering anthropic technological activities and even human health and safety. Thus, an essential activity in the framework of space-weather monitoring is devoted to the observation of the activity level on th…
Long-term variation of coronal holes latitudinal distribution
Chargeishvili, B. B.; Maghradze, D. A.; Japaridze, D. R. +2 more
We study the evolution of the latitudinal distribution of coronal holes using the Solar and Heliospheric Observatory (SOHO)/Extreme ultraviolet Imaging Telescope (EIT) 195 Å data from 1996 May to 2020 April. To measure the presence of coronal holes at a given latitude, we use the presence factor, which estimates the length of an object along a giv…
Infrared-radio relation in the local Universe
De Zotti, G.; Tisanić, K.; Amiri, A. +3 more
Context. The Square Kilometer Array (SKA) is expected to detect high-redshift galaxies with star formation rates (SFRs) up to two orders of magnitude lower than Herschel surveys and will thus boost the ability of radio astronomy to study extragalactic sources. The tight infrared-radio correlation offers the possibility of using radio emission as a…
The Orbits and Dynamical Masses of the Castor System
Torres, Guillermo; Klement, Robert; Monnier, John D. +12 more
Castor is a system of six stars in which the two brighter objects, Castor A and B, revolve around each other every ~450 yr and are both short-period spectroscopic binaries. They are attended by the more distant Castor C, which is also a binary. Here we report interferometric observations with the Center for High Angular Resolution Astronomy (CHARA…
Search for Close Stellar Encounters with the Solar System Based on Data from the Gaia DR3 Catalogue
Bobylev, V. V.; Bajkova, A. T.
We have searched for close stellar encounters with the Solar System using data from the Gaia DR3 catalogue. We have considered 31 stars with an encounter parameter $d_min<1$ pc. Among them 15 stars act as candidates for close encounters for the first time. The status of the stars GJ 710 and HD 7977 as candidates for deep penetration into the in…
At What Mass Are Stars Braked? The Implication from the Turnoff Morphology of NGC 6819
Huang, Yang; Li, Chengyuan; Yang, Yong +1 more
Extended main-sequence turnoffs (eMSTOs) apparent in most young and intermediate-age clusters (younger than ~2 Gyr) are known features caused by fast rotating early-type (earlier than F-type) stars. Late-type stars are not fast rotators because their initial angular momenta have been quickly dispersed due to magnetic braking. However, the mass lim…
Abundance of zirconium in the globular cluster 47 Tucanae: a possible Zr-Na correlation?*
Bonifacio, P.; Korotin, S.; Kučinskas, A. +2 more
We determined abundances of Na and Zr in the atmospheres of 237 RGB stars in Galactic globular cluster (GGC) 47 Tuc (NGC 104), with a primary objective of investigating possible differences between the abundances of Zr in the first generation (1P) and second generation (2P) stars. For the abundance analysis, we used archival UVES/GIRAFFE spectra o…
Be, V, and Cu in the halo star CS 31082-001 from near-UV spectroscopy
Spite, M.; Evans, C. J.; Barbuy, B. +5 more
The 'First Stars' programme revealed the metal-poor halo star CS 31082-001 to be r-process and actinide rich, including the first measurement of a uranium abundance for an old star. To better characterize and understand such rare objects, we present the first abundance estimates of three elements (Be, V, Cu) for CS 31082-001 from analysis of its n…
Decade-long time-monitoring of candidate luminous blue variable stars in the two very metal-deficient star-forming galaxies DDO 68 and PHL 293B
Thuan, T. X.; Izotov, Y. I.; Guseva, N. G.
We have studied the spectral time variations of candidate luminous blue variable (cLBV) stars in two low-metallicity star-forming galaxies, DDO 68 and PHL 293B. The LBV in DDO 68, located in H II region #3, shows an outburst, with an increase of more than 1000 times in H α luminosity during the period 2008-2010. The broad emission of the H I and H…
ALMA's view of the M-dwarf GSC 07396-00759's edge-on debris disc: AU Mic's coeval twin
Kral, Quentin; Murphy, Simon J.; Wyatt, Mark C. +7 more
We present new ALMA Band 7 observations of the edge-on debris disc around the M1V star GSC 07396-00759. At ~20 Myr old and in the β Pictoris Moving Group along with AU Mic, GSC 07396-00759 joins it in the handful of low-mass M-dwarf discs to be resolved in the sub-mm. With previous VLT/SPHERE scattered light observations, we present a multiwavelen…