Joaquín Garcia

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52 Following
194 Posts
Físico. Profesor jubilado. Amante de la Astronomía. Me gustan los exoplanetas. Me gusta la geología y la biología. Tengo un blog https://xgarciaf.blogspot.com/
Bloghttps://xgarciaf.blogspot.com/
Twitterhttps://twitter.com/GarciafXimo

Today on the arXiv:

Changeat et al. 2024, "Is the atmosphere of the ultra-hot Jupiter WASP-121b variable?" - https://arxiv.org/abs/2401.01465.

Featuring large scale weather patterns in clouds of titanium oxide.

QT Hubble @NASAHubble
2023 January 4

Weather report from exoplanet WASP- 121b:

- Daytime temperature of 3,450 degrees Fahrenheit (2,150 degrees Kelvin)
- Massive cyclones
- Orbiting dangerously close to its host star!

For three years, Hubble studied changes in the atmosphere of this planet.

Is the atmosphere of the ultra-hot Jupiter WASP-121b variable?

We present a comprehensive analysis of the Hubble Space Telescope observations of the atmosphere of WASP-121 b, a ultra-hot Jupiter. After reducing the transit, eclipse, and phase-curve observations with a uniform methodology and addressing the biases from instrument systematics, sophisticated atmospheric retrievals are used to extract robust constraints on the thermal structure, chemistry, and cloud properties of the atmosphere. Our analysis shows that the observations are consistent with a strong thermal inversion beginning at ~0.1 bar on the dayside, solar to subsolar metallicity Z (i.e., -0.77 < log(Z) < 0.05), and super-solar C/O ratio (i.e., 0.59 < C/O < 0.87). More importantly, utilizing the high signal-to-noise ratio and repeated observations of the planet, we identify the following unambiguous time-varying signals in the data: i) a shift of the putative hotspot offset between the two phase-curves and ii) varying spectral signatures in the transits and eclipses. By simulating the global dynamics of WASP-121 b atmosphere at high-resolution, we show that the identified signals are consistent with quasi-periodic weather patterns, hence atmospheric variability, with signatures at the level probed by the observations (~5% to ~10%) that change on a timescale of ~5 planet days; in the simulations, the weather patterns arise from the formation and movement of storms and fronts, causing hot (as well as cold) patches of atmosphere to deform, separate, and mix in time.

arXiv.org
So far so good. OSIRIS-APEX has survived it's closest approach to the Sun. The spacecraft is continuing to send telemetry as it moves further away from the Sun towards Near Earth Asteroid Apophis https://blogs.nasa.gov/osiris-apex/2023/12/01/nasas-osiris-apex-to-fly-closer-to-sun-to-reach-asteroid-apophis/ #astrodon
NASA’s OSIRIS-APEX to Fly Closer to Sun to Reach Asteroid Apophis – OSIRIS-APEX

Phase curve of GJ 367 b observed with the #JWST.

GJ 367b is a hot, extremely dense sub-Earth #exoplanet orbiting a M dwarf on a 0.32-day orbit.

The observations are fully consistent with a zero-albedo #planet with no heat recirculation.

The lack of heat recirculation implies that 1 bar atmospheres are ruled out, while 0.1 bar atmospheres are consistent with the data.

The planet must have lost the vast majority of its initial inventory of volatiles.

#exoplanets
https://astrobiology.com/2024/01/gj-367b-is-a-dark-hot-airless-sub-earth.html

GJ 367b Is A Dark, Hot, Airless Sub-Earth - Astrobiology

We present the mid-infrared (5-12 μm) phase curve of GJ 367b observed by the Mid-Infrared Instrument (MIRI) on the James Webb Space Telescope (JWST).

Astrobiology
Las montañas de hielo de Plutón, de hasta 3.400 metros de altura y ubicadas en Sputnik Planitia, son geológicamente jóvenes, formadas hace menos de 100 millones de años. Su crecimiento continuo indica una fuente de calor interno en el planeta.
Un estudio sugiere que la Tierra esconde restos de otro planeta en su interior

Las enigmáticas capas densas del manto terrestre podrían ser vestigios de la colisión contra el protoplaneta Tea hace 4.500 millones de años

El País
Gagarin nuestro adelantado en las estrellas. @el_pais
Malauradament han publicat una versió anterior: l'esposa de Leopoldo es deia Maria i hi ha un error al psicomòmetre de doble entrada. Dóna la humitat relativa en funció de la diferència de temperatures i la temperatura del sec.
La NASA halla indicios de los “componentes básicos de la vida” en el polvo oscuro traído desde el asteroide Bennu https://elpais.com/ciencia/2023-10-11/la-nasa-halla-indicios-de-los-componentes-basicos-de-la-vida-en-el-polvo-oscuro-traido-desde-el-asteroide-bennu.html
La NASA halla indicios de los “componentes básicos de la vida” en el polvo oscuro traído desde el asteroide Bennu

Los restos de la roca espacial recogidos por la sonda ‘OSIRIS-REx’ de la NASA contienen agua y carbono, lo que refuerza la idea de que esos elementos pudieron llegar a la Tierra en meteoritos

El País
La muestra del asteroide Bennu de la NASA contiene carbono y agua. En conjunto podrían indicar que los componentes básicos de la vida en la Tierra se pueden encontrar en la roca. https://www.nasa.gov/news-release/nasas-bennu-asteroid-sample-contains-carbon-water/
NASA’s Bennu Asteroid Sample Contains Carbon, Water - NASA

Initial studies of the 4.5-billion-year-old asteroid Bennu sample collected in space and brought to Earth by NASA show evidence of high-carbon content and

NASA

Solving the mystery of how #planets like Earth form is an important question for understanding the origin of life.

Planets are thought to form when interstellar dust and gas collect in a #protoplanetary disk surrounding a #protostar, but it has been unclear how #planet formation begins.

By observing protoplanetary disks without dark rings, astronomers can study systems where giant planets have not yet formed.

https://phys.org/news/2023-10-astronomers-planet-formation.html

Paper by Ohashi et al. (2023):
https://iopscience.iop.org/article/10.3847/1538-4357/ace9b9

Astronomers discover first step toward planet formation

Solving the mystery of how planets like Earth were formed is an important question for understanding the origin of life. Planets are thought to form when interstellar dust and gas collect in a protoplanetary disk surrounding a protostar, but it has been unclear where, when, or how planet formation begins.

Phys.org