ASTRONOMY - The Protostars within Lynds 483

 2025 March 13

The Protostars within Lynds 483
Image Credit: NASA, ESA, CSA,

Explanation: Two protostars are hidden in a single pixel near the center of a striking hourglass-shaped nebula in this near-infrared image from the James Webb Space Telescope. The actively forming star system lies in a dusty molecular cloud cataloged as Lynds 483, some 650 light-years distant toward the constellation Serpens Cauda. Responsible for the stunning bipolar outflows, the collapsing protostars have been blasting out collimated energetic jets of material over tens of thousands of years. Webb's high-resolution view shows the violence of star-formation in dramatic detail as twisting shock fronts expand and collide with slower, denser material. The premier close-up of the star-forming region spans less than 1/2 a light-year within dark nebula Lynds 483.

ASTRONOMY - NGC 772: The Fiddlehead Galaxy

 2025 March 12

NGC 772: The Fiddlehead Galaxy
Image Credit & Copyright: Jean-François Bax & Serge Brunier, OCA/C2PU; Text: Ogetay Kayali (Michigan Tech U.)

Explanation: Why does this galaxy look like a curly vegetable? The Fiddlehead spiral galaxy likely gets its distorted spiral appearance from a gravitational interaction with its close-by elliptical companion NGC 770, seen just below. Cataloged as NGC 772 and Arp 78, the Fiddlehead spans over 200,000 light years, is a nearby 100 million light years beyond the stars of our Milky Way galaxy, and is visible toward the constellation of the Ram (Aries). But in the featured image, the Fiddlehead appears to have another companion -- one with a long and fuzzy tail: Comet 43P/Wolf-Harrington. Though the comet appears to be aimed straight at the massive galaxy, it is actually much closer to us, residing only light minutes away -- well within our Solar System. The comet will never reach the distant spiral galaxy, nor is it physically related to it. By a fortunate trick of perspective, though, these two cosmic wonders briefly share the same frame taken late last year from Calern, France.

ASDTRONOMY - NGC 1672: Barred Spiral Galaxy from Hubble

 2025 March 11

NGC 1672: Barred Spiral Galaxy from Hubble
Image Credit: ESA/Hubble & NASA, O. Fox, L. Jenkins, S. Van Dyk, A. Filippenko, J. Lee and the PHANGS-HST Team, D. de Martin (ESA/Hubble), M. Zamani (ESA/Hubble)

Explanation: Many spiral galaxies have bars across their centers. Even our own Milky Way Galaxy is thought to have a modest central bar. Prominently barred spiral galaxy NGC 1672, featured here, was captured in spectacular detail in an image taken by the orbiting Hubble Space Telescope. Visible are dark filamentary dust lanes, young clusters of bright blue stars, red emission nebulas of glowing hydrogen gas, a long bright bar of stars across the center, and a bright active nucleus that likely houses a supermassive black hole. Light takes about 60 million years to reach us from NGC 1672, which spans about 75,000 light years across. NGC 1672, which appears toward the constellation of the Dolphinfish (Dorado), has been studied to find out how a spiral bar contributes to star formation in a galaxy's central regions.

ARCHEOLOGIE - Toutânkhamon, chassant au harpon

Ce sont des figurines rituelles du pharaon Toutânkhamon. Elles montrent le jeune roi dans ses activités quotidiennes, des scènes rituelles de chasse à l'hippopotame et de pêche au harpon. Le souverain est tantôt coiffé d'une sorte de mitre blanche, oblongue (statuette au centre), le Hedjet qui est la couronne de la Haute-Égypte ; tantôt coiffé du Decheret, couronne rouge, celle de la Basse-Égypte (statuettes à gauche et à droite). Parfois, il porte les deux emboîtées l'une sur l'autre en signe de souveraineté unifiée, la double couronne s'appelle alors le Pschent. Le pharaon est vêtu du pagne plissé.

Le style amarnien transparaît ici : il se distingue par un art délicat et des personnages à la bouche charnue, un ventre renflé, un cou tendu et des formes allongées ; c'est une esthétique propre au règne de son père Akhenaton. Lorsqu'elles ont été découvertes, ces figurines étaient toutes délicatement vêtues de toile de lin.

© Claude Valette, CC by-nc 2.0

SANTé/MEDECINE - Le râle agonique - Un processus naturel

Le râle agonique est l’un des signes marquants de la fin de vie, indiquant que le corps se prépare à s’éteindre. Bien que ce son puisse être troublant pour les proches, il est essentiel de garder à l’esprit qu’il ne provoque ni douleur ni souffrance chez la personne mourante.

En comprenant ce phénomène et en s’appuyant sur l’accompagnement des professionnels de santé, il devient possible de se concentrer sur l’essentiel : offrir à son proche un environnement apaisant et réconfortant. Parfois, un simple geste comme tenir une main, parler doucement ou être simplement présent suffit à apporter un profond apaisement dans ces derniers instants. Accepter ce processus comme une partie naturelle de la vie permet d’accompagner avec sérénité et amour ceux qui s’en vont.

©freepik

ASTRONOMY - NGC 1499: The California Nebula

 2025 March 10

NGC 1499: The California Nebula
Image Credit & Copyright: Toni Fabiani Mendez

Explanation: Could Queen Calafia's mythical island exist in space? Perhaps not, but by chance the outline of this molecular space cloud echoes the outline of the state of California, USA. Our Sun has its home within the Milky Way's Orion Arm, only about 1,000 light-years from the California Nebula. Also known as NGC 1499, the classic emission nebula is around 100 light-years long. On the featured image, the most prominent glow of the California Nebula is the red light characteristic of hydrogen atoms recombining with long lost electrons, stripped away (ionized) by energetic starlight. The star most likely providing the energetic starlight that ionizes much of the nebular gas is the bright, hot, bluish Xi Persei just to the right of the nebula. A regular target for astrophotographers, the California Nebula can be spotted with a wide-field telescope under a dark sky toward the constellation of Perseus, not far from the Pleiades.

SANTé/MEDECINE - Le râle agonique - Ce que les proches doivent savoir

Entendre le râle agonique peut être une expérience difficile et bouleversante pour les proches. Pourtant, il est important de se rappeler que ce bruit est une étape naturelle du processus de fin de vie et qu’il ne provoque aucune douleur chez la personne mourante.

©freepik

ASTRONOMY - Cyclones at Jupiter's North Pole

 2025 March 9

Cyclones at Jupiter's North Pole
Image Credit: NASA, JPL-Caltech, SwRI, ASI, INAF, JIRAM

Explanation: Why are there so many cyclones around the north pole of Jupiter? The topic is still being researched. NASA's robotic Juno mission orbiting Jupiter took data in 2018 that was used to construct this stunning view of the curious cyclones at Jupiter's north pole. Measuring the thermal emission from Jovian cloud tops, the infrared observations are not restricted to the hemisphere illuminated by sunlight. They reveal eight cyclonic features that surround a cyclone about 4,000 kilometers in diameter, just offset from the giant planet's geographic north pole. Similar data show a cyclone at the Jovian south pole with five circumpolar cyclones. The south pole cyclones are slightly larger than their northern cousins. Oddly, data from the once Saturn-orbiting Cassini mission has shown that Saturn's north and south poles each have only a single cyclonic storm system.

ASTRONOMIE - Collision de deux galaxies

La collision de deux galaxies connues sous le nom de NGC 7252 et NGC 7582 dans la constellation du Verseau, photographiée par l'un des télescopes de l'ESO. 

© ESO

ASTRONOMY - Galaxies in Space

 2025 March 8

Galaxies in Space
Image Credit & License: NASA, ISS Expedition 72, Don Petit

Explanation: The plane of our Milky Way galaxy extends beyond the limb of planet Earth in this space age exposure captured by astronaut Don Pettit. His camera, with low light and long duration settings, was pointed out the window of a Dragon crew spacecraft docked with the International Space Station on January 29. The orbital outpost was at an altitude of about 400 kilometers above the Pacific Ocean at the time. Motion blurs the Earth below, while the gorgeous view from low Earth orbit includes the Milky Way's prominent satellite galaxies, known as the Large and Small Magellanic Clouds, near the upper left in the frame. Fans of southern skies can also spot the Southern Cross. The four brightest stars of the famous southern constellation Crux are near picture center, just beyond the edge of the bright horizon and shining through Earth's orange tinted atmospheric glow.