Near-Earth asteroid 2012 DA14 made its closest approach on February 15, 2013, when it passed at a distance of 27,700 km from the Earth’s surface. It was the first time an asteroid of moderate size was predicted to approach that close to the Earth, becoming bright enough to permit a detailed study from ground-based telescopes. Asteroid 2012 DA14 was poorly characterized before its closest approach. The main objective of this work was to obtain new and valuable data to better understand its physical properties, and to evaluate the effects of such a close approach on the object. We acquired data using several telescopes on four Spanish observatories: the 10.4 m Gran Telescopio Canarias (GTC) and the 3.6 m Telescopio Nazionale Galileo (TNG), both in the El Roque de los Muchachos Observatory (ORM, La Palma); the 2.2 m CAHA telescope, in the Calar Alto Observatory (Almería); the f/3 0.77 m telescope in the La Hita Observatory (Toledo); and the f/8 1.5 m telescope in the Sierra Nevada Observatory (OSN, Granada). We obtained visible and near-infrared color photometry, visible spectra and time-series photometry. Visible spectra together with visible and near-infrared color photometry of 2012 DA14 show that the object can be classified as an L-type asteroid, a rare spectral type among the asteroid population, with a composition similar to that of carbonaceous chondrites. The time-series photometry provides a rotational period of 8.95 ± 0.08 h after the closest approach, and there are indications that the object suffered a spin-up during this event. The large amplitude of the light curve suggests that the object is very elongated and irregular, with an equivalent diameter of around 18 m. We obtain an absolute magnitude of HR = 24.5 ± 0.2, corresponding to HV = 25.0 ± 0.2 in V. The GTC photometry also gives HV = 25.29 ± 0.14. Both values agree with the value listed at the Minor Planet Center (MPC) shortly after discovery, although HV is very sensitive to the slope parameter G used to correct for phase angle. From the absolute photometry, together with some constraints on size and shape, we compute a geometric albedo of pV = 0.44 ± 0.20, which is slightly above the range of albedos known for L-type asteroids (0.082−0.405).
It may interest you
Red dwarfs are the most common stars in the galaxy. In recent years they have become key targets in the search for exoplanets. These stars are usually accompanied by rocky planets and due to their low brightness, their habitable zone is close to the star, making it easier to find planets that are within it. GJ 1002 is a red dwarf just one-eighth the mass of the Sun, located only 15.8 light-years away. Using radial velocity measurements from the ESPRESSO and CARMENES spectrographs, we have discovered the presence of two Earth-like and potentially habitable planets. The planets, GJ 1002 b andAdvertised on
When matter falls into supermassive black holes in the centres of galaxies, it unleashes enormous amounts of energy and is called active galactic nuclei (or AGN). A fraction of AGN release part of this energy as jets that are detectable in radio wavelengths that travel at velocities close to light speed. Our research into the interplay between the jet and the cold gas in the Teacup galaxy helps us to better understand how galaxies evolve. The Teacup is a radio-quiet quasar located 1.3 billion light years from us and its nickname comes from the expanding bubbles seen in the optical and radioAdvertised on
The standard cosmological model states that massive galaxies contain a large fraction of dark matter. Dark matter is a transparent substance that does not interact through regular baryonic matter and is only detected through its gravitational pull over the stars and the gas. NGC 1277 is known as the prototype of a relic galaxy, that is, a galaxy that has not accreted other galaxies since it formed. Relic galaxies are extremely rare and are the untouched remains of the giant galaxies that populated the early Universe. Since relic galaxies are very important to understand the conditions in theAdvertised on