Romanian Astronomical Journal is an international journal covering the fields of:
Asteroid (6478) Gault is a mysterious object; although it is in the Main Belt of asteroids, this object presents a cometary activity. During 2018 and 2019 astronomers detected a tail of matter in the asteroid's motion around the Sun, most likely due to the sublimation of light elements in its composition. The phenomenon involves the particles of dust and gas that reflect sunlight.
An international team that includes researchers from MIT-US, Astronomical Institute of the Romanian Academy, Weizmann Institute of Science in Israel, Observatoire de Paris-France, Lowell Observatory, Institute for Astronomy in Hawaii, and Northern Arizona University, has monitored the asteroid and obtained spectral and photometric data of Gault, between March and April 2019. Near-infrared spectral observations were performed in late March and early April 2019 with the 3 m diameter IRTF (NASA) telescope located in Mauna Kea-Hawaii; the spectral data were corroborated with the photometric data (Figure 1) obtained with the NEEMO-T05 telescope operated by the Astronomical Institute of the Romanian Academy.
Observational data confirm that the surface of the object contains minerals rich in silicium, most likely similar to the mineralogical composition of the asteroid family (25) Phocaea. The spectral data show variations of the spectral slope, decorrelated by a possible burst in object's cometary activity. This aspect can be explained by observing a new layer, unaltered by space weather, predominantly present on the surface of the object after the initial dust layer was entrained in the tail developed by the asteroid.
These results were recently published in the prestigious Astrophysical Journal Letters.M. Marsset, F. DeMeo, A. Sonka, et al., "Active asteroid (6478) Gault: a blue Q-type surface below the dust?” accepted in Astrophysical Journal Letters. Contacts: Adrian Sonka, Astronomical Institute of the Romanian Academy, Mirel Birlan, Paris Observatory.
The Sun is the main driver of space weather. Space weather is determining the state of the Earth magnetosphere, which, in its turn, triggers geomagnetic storms.
Coronal mass ejections (CMEs) are pieces of the puzzle that drive space weather. They are one of the most important pieces, because of their large quantities of magnetised plasma released into the heliosphere. An Earth directed CME can hit the magnetosphere about 2-4 days after its initial detection, but not all CMEs arriving to Earth will produce a geomagnetic storm.
Numerous methods (theoretical, numerical and empirical) are being used to predict whether the CME will be geoeffective or not. In a recent paper, a team of researchers lead by D. Beșliu-Ionescu have proposed a new logistic regression model that will produce a probability, expressed as a number between 0 and 1, that a CME will be an event associated with a geomagnetic storm (Beșliu-Ionescu et al., 2019).
Berthelot Observatory is a remote observing station of the Astronomical Institute. Built on General Berthelot village, Hunedoara, on a protected area belonging to the Romanian Academy, the observatory is operated in remote mode from Bucharest. Following the first light in mid-November 2018, the observatory is currently involved in near-Earth objects photometric surveys and tracking and surveillance activities in the framework of EU-SST programme of the European Commission.
The telescope is a RC 14.5'' F/7 Optical Guidance System on a fast, 8°/s, equatorial mount able to track objects on medium Earth orbits. The field of view, using an SBIG STL11000M CCD camera, is of 44'x30'.
Berthelot Observatory successfully concluded the first common European exercise of space surveillance and tracking taking place from 15 to 24 July 2019. Astrometry data for the four assigned targets was provided daily in TDM format.