Re-encounter with a planetary nebula nearly 30 years later
January 13th 2022
The Institute of Astrophysics of Andalusia (IAA-CSIC) leads a study based on data from Calar Alto Observatory (CAHA), showing the variability of the planetary nebula IC4997. The changes can be seen comparing observations taken nearly 30 years apart with the CAHA 2.2-meter telescope. This suggests that the central star of this planetary nebula probably hides a companion star.
Planetary nebulae represent one of the final stages in the life of low- and intermediate-mass stars, similar to the Sun. After exhausting their fuel, the outer layers of such stars are taken off, forming a fluorescent envelope around a white dwarf star (the "naked" core of the star after the expulsion of its outer layers). In some tens of thousands of years, the nebula will disperse in the interstellar medium and the central star will become extinct, so that all planetary nebulae are expected to be (very slowly) variable. However, some of them present a variability unrelated to their natural evolution, which reveals processes that deviate from the norm. This is the case of IC4997, a nebula with which a Spanish team led by the Institute of Astrophysics of Andalusia (IAA-CSIC) has found itself again, thirty years later.
First-time detection of oxygen in the atmosphere of an ultra-hot exoplanet
December 22nd 2021
Reanalyzing CARMENES observations of the Kelt-9b exoplanet, taken at Calar Alto, an international team with participation of the Institute of Astrophysics of Andalusia (IAA-CSIC) has revealed the presence of oxygen in this exoplanet atmosphere, the hottest known to date. It is the very first time that atoms of oxygen are detected in a planet outside the Solar System.
Since the discovery, in 1995, of the first planet outside of our Solar System, more than four thousand exoplanets have been detected. During these decades, science teams from all over the world have tried to characterize their atmospheres and to explain why these new worlds are so different from the planets of the Solar System. Now, an international team, with participation of the Institute of Astrophysics of Andalusia, publishes in the Nature Astronomy journal the finding of atoms of oxygen in the exoplanet named Kelt-9b. It is the very first detection of the compound, that human beings commonly associate to life, in the atmosphere of an exoplanet.
Calar Alto is involved in an international campaign to study changes in the brightness of Venus
September 24th 2021
The planet Venus is permanently covered by high clouds that extend over a thick atmosphere that hide from direct view the hottest planetary surface (about 460°C) in the Solar System. Three Calar Alto telescopes participate in an ambitious campaign of Venus observations combining data from different space missions and ground-based telescopes to understand Venus’ cloud layers and possible changes in the planet’s brightness. The first results of this campaign are presented these days at the Europlanet Science Congress.
Venus is the planet that has the closest approach to Earth, but its surface remains invisible, fully hidden by thick layers of clouds that reflect most of the sunlight making Venus the brightest planet as observed from Earth. Despite being so close and bright, Venus holds several mysteries in its atmosphere and its surface. One of the most recently discovered is the changes in the global brightness of the upper clouds detected when comparing images of Venus obtained on different years. What causes those changes, and what is their impact in the atmosphere and surface are still largely unknown.
Giant planets could reach maturity sooner than expected
December 2nd 2021
Calar Alto Observatory and the Institute of Astrophysics of Andalusia (IAA-CSIC) participate in the study of the giant planets of the V1298 Tauri system, which in just twenty million years have already reached their final size: a contraction time much shorter than expected. The finding has been possible thanks, in particular, to radial velocity measurements from the HARPS-N spectrographs, at Roque de los Muchachos Observatory (ORM), and from CARMENES, at Calar Alto Observatory (CAHA)
Current theories of planetary evolution predict that giant planets, such as Jupiter or Saturn, are born with large dimensions and very low densities and that, after hundreds of millions of years of slow contraction, they reach their final size. However, these expectations do not have corroborating evidence, and a recent finding shows that they may not correspond to reality in some cases. An international scientific team has measured the mass of the planets of the V1298 Tauri system, one of the youngest known, and concludes that the giant planets could complete their contraction much faster than expected. The result is published in the journal Nature Astronomy.
Remote detection of viruses on surfaces
August 10th 2021
Researchers from the Universidad de Sevilla have developed and patented a prototype to detect remotely viruses (including synthetic SARS-CoV-2) deposited on surfaces, analyzing images taken at multiple wavelengths – the so-called hyperspectral imaging – a technique commonly used in astrophysics. Astronomers from Calar Alto and IAA-CSIC have participated in the reduction and analysis of the spectra. The research is ongoing on human samples of coronavirus.
A group of researchers based in Spain and, particularly, in Andalusia, has designed a new optical technique allowing them to detect the presence of viruses in drops of fluids or in dry residuals spread over a surface. The work is led by Prof. Emilio Gómez-González, full professor of applied physics at ETS Engineering School at Universidad de Sevilla. The research, sponsored by the Institute of Health ‘Carlos III’, has resulted in a patented technique able to analyze simultaneously numerous samples, without the need to touch them nor to use reagents.
The first binary star of its kind discovered with the Schmidt telescope
November 23rd 2021
Pointing the Schmidt telescope at Calar Alto, a volunteer scientist observing for the European Space Agency has discovered a new type of cataclysmic variable star, the first eclipsing stream-fed intermediate polar binary star. In this kind of “violent couple”, one of the stars (the white dwarf) pulls out matter from its partner (the red dwarf) towards its magnetic poles in huge streams of gas and dust.
Using the Calar Alto Schmidt telescope as part of the Space Situational Awareness Program of the European Space Agency (ESA), Erwin Schwab, an amateur astronomer and volunteer scientist for ESA, was searching for the lost comet P/2012 K3 (Gibbs). In the night from July 26 to 27, 2019, he took series of images from the predicted position in the constellation Sagittarius. The comet was not there… Yet, during the data inspection, Schwab noticed a star in the field, which suddenly disappeared from one picture to the next. The faint variable object was cataloged as J1832.4-1627 from its coordinates on the sky. After further observing nights with the Schmidt and other telescopes, he was able to detect several deep eclipses of the star, which occurred every 9 hours or so.
CARMENES discovers two planetary systems made of (super-)Earths
June 30th 2021
The CARMENES instrument at the Calar Alto observatory 3.5-meter telescope finds one exo-Earth and two super-Earths around two red dwarf stars, confirming the ubiquity of rocky planets around such tiny stars, whose violent flares may complicate and even prevent the detection of exoplanets.
Since 1995, over 4000 planets have been discovered out of our Solar System. The ample variety of these exoplanets has demonstrated that the structure of the Solar System, with rocky (or terrestrial) planets in the inner regions and gaseous and icy ones in the outer parts, is not so typical as believed. Other configurations, such as gas giant planets very close to their stars or systems with several super-Earths around dwarf stars, appear more common. In this context, a new detection of two planetary systems by the CARMENES instrument, operating at Spanish Calar Alto Observatory (CAHA, Almeria), reinforces the idea that dwarf stars tend to harbor rocky planets.
