Berthelot Observatory Survey recently reported the detection of an unusual tail of comet 246P/NEAT. The discovery, submitted to Central Bureau for Astronomical Telegrams, was published as CBET 4799. The CBET is available bellow:
Further to CBET 4793, A. Sonka, M. Birlan, and A. Nedelcu, Berthelot Observatory, Astronomical Institute of the Romanian Academy, report on the unusual shape and tail of comet 246P from CCD observations obtained with a 0.38 m f/8 reflector (39'.8 x 28' field-of-view) at Berthelot Observatory on May 12, 21, and 23. A 60-s unfiltered exposure taken on May 23 shows an obvious 3' fanlike tail in p.a. 292.8 degrees, while 46 stacked images having a total exposure time of 0.8 hr shows a long tail visible at p.a. 296.8 degrees; the tail is at least 28' long and shows a 5'.4-long discontinuity, starting at 3' from the comet's coma (after the discontinuity ends, the tail continues and possibly extends outside the field-of-view. The comet's tail is also visible in images taken on May 12 and 21 at p.a. 296.8 degrees. The discontinuity is 5' long on May 12 and 8' long on May 21. Additional unfiltered CCD total-magnitude and coma-diameter measurements for comet 246P: Mar. 20.27 UT, 15.0, 40" (H. Sato, Tokyo, Japan, 0.25-m astrograph near Mayhill, NM, USA; fan-like tail 1'.5 long toward p.a. 250-290 degrees); May 29.44, 14.6, -- (K. Kadota, Ageo, Japan, 0.25-m reflector). Visual total-magnitude and coma-diameter estimates by P. Camilleri, Katherine, NT, Australia (0.40-m reflector): June 9.47, 13.8, 1'; June 14.45, 14.0, 1'.contact: sonka (at) astro.ro
The Astronomical Institute and the Astronomia 21 organisation are contributing to #StayAtHome Covid19-related state.
In the frame of “Școala altfel” – “A different type of learning”, on March 31, 2020, Diana Beșliu-Ionescu has presented “The Sun and its consequences on life” to a class of fourth grade students from ”Grigorie Ghica Voievod” Gymnasium School. Using Google Meet, available on the G Suite for education, students were able to follow our researcher’s presentation.
They have learned about the Sun’s position relative to our Galaxy, its evolution and structure. The students were most impressed by the scaled difference between Sun and Earth sizes represented using a 60 cm diameter yoga ball and a very small metal marble. Students also watched high-resolution animation provided by DOT showing photospheric activity around an active region. The presentation described what is a solar cycle, which eruptive events may influence the Earth and produce geomagnetic storms. At the end students were told that their phones can show the space weather status using NASA/ESA’s Apps.
Dr. Mirel Birlan, researcher at Paris Observatory and the Astronomical Institute of the Romanian Academy is part of a team of researchers that has looked up-close at the Pallas asteroid, the third largest object in the asteroid belt, to better understand its unusual tilted orbit. The team discovered that the surface of the asteroid is so cratered, that researchers dubbed it “the golf ball asteroid”. The research team believes that the craters are a consequence of a violent period of collision during its history and that this could also explain the unusual inclination of its orbit that has puzzled scientists for centuries.
The Pallas asteroid is almost one-seventh the size of the Moon. For centuries, astronomers have noticed that the asteroid orbits along a significantly tilted track compared with the majority of objects in the asteroid belt. This inclination remained a mystery for a long time. Now a European team, led by principal investigator Pierre Vernazza from the Laboratoire d'Astrophyisque de Marseille in France, and including Dr. Mirel Birlan, obtained images of Pallas using ESO’s Very Large Telescope (VLT), an array of four telescopes, each with an 8-meter-wide mirror, situated in the mountains of Chile.
The high resolution images show a very cratered surface of the asteroid. In addition, the researchers created a reconstructed 3D model of the shape of the asteroid, revealing a heavily cratered object on the poles, but also at the equatorial regions. The researchers identified 36 craters larger than 30 kilometres in diameter, covering more than 10% of its surface — proof that Pallas experienced a violent period of collision during its history, two to three times more intense than the one of other large asteroids like Ceres or Vesta. The heavily cratered surface explains also the preservation of its initial shape after the formation. This collisional period could also explain Pallas’ tilted orbit.
The images of the asteroid have also revealed a bright spot on the surface of Pallas. The most probable explanation of this finding and its origin is that Pallas has large deposits of salts at its surface, most probably formed by a mixture of water and silicates. The investigations carried out by the European team have also led to the discovery of the Pallas family of asteroids, a cluster of small asteroids. Simulations of impacts with Pallas suggest that this family could be the result of a violent collision about 1.7 billion years ago by an object having a diameter between 20 km and 40 km. Asteroid 3200 Phaeton, identified as the source of the Geminids meteor shower, which is observed on Earth in December, is part of the Pallas family, and could provide clues to understanding the origin of the parent body, Pallas. Thus, observing meteors and collecting meteorites coming from Phaeton could partly solve the history of Pallas.
The findings were published in Nature Astronomy https://www.nature.com/articles/s41550-019-1007-5.