Re-encounter with a planetary nebula nearly 30 years later

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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.

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First-time detection of oxygen in the atmosphere of an ultra-hot exoplanet

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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.

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Giant planets could reach maturity sooner than expected

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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.

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The first binary star of its kind discovered with the Schmidt telescope

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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.

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