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24/02/2023

ASTRONOMY - Jones-Emberson 1

 023 February 24

See Explanation.  Clicking on the picture will download
the highest resolution version available.

Jones-Emberson 1
Image Credit & CopyrightSerge Brunier, Jean-François Bax, David VernetC2PU/OCA

Explanation: Planetary nebula Jones-Emberson 1 is the death shroud of a dying Sun-like star. It lies some 1,600 light-years from Earth toward the sharp-eyed constellation Lynx. About 4 light-years across, the expanding remnant of the dying star's atmosphere was shrugged off into interstellar space, as the star's central supply of hydrogen and then helium for fusion was finally depleted after billions of years. Visible near the center of the planetary nebula is what remains of the stellar core, a blue-hot white dwarf star. Also known as PK 164 +31.1, the nebula is faint and very difficult to glimpse at a telescope's eyepiece. But this deep broadband image combining 22 hours of exposure time does show it off in exceptional detail. Stars within our own Milky Way galaxy as well as background galaxies across the universe are scattered through the clear field of view. Ephemeral on the cosmic stage, Jones-Emberson 1 will fade away over the next few thousand years. Its hot, central white dwarf star will take billions of years to cool.

23/02/2023

ASTRONOMY - Arp 78: Peculiar Galaxy in Aries

 2023 February 23

See Explanation.  Clicking on the picture will download
the highest resolution version available.

Arp 78: Peculiar Galaxy in Aries
Image Credit & CopyrightJosep Drudis

Explanation: Peculiar spiral galaxy Arp 78 is found within the boundaries of the head strong constellation Aries. Some 100 million light-years beyond the stars and nebulae of our Milky Way galaxy, the island universe is an enormous 200,000 light-years across. Also known as NGC 772, it sports a prominent, outer spiral arm in this detailed cosmic portrait. Tracking along sweeping dust lanes and lined with young blue star clusters, Arp 78's overdeveloped spiral arm is pumped-up by galactic-scale gravitational tides. Interactions with its brightest companion galaxy, the more compact NGC 770 seen above and right of the larger spiral, are likely responsible. Embedded in faint star streams revealed in the deep telescopic exposure, NGC 770's fuzzy, elliptical appearance contrasts nicely with spiky foreground Milky Way stars in matching yellowish hues.

22/02/2023

ASTRONOMY - Our Increasingly Active Sun

 2023 February 22

The Sun is pictured in a color that allows high detail. The
large orange ball has several bright streaks and a carpet-like
texture. Several prominences are visible around the edges.
Please see the explanation for more detailed information.

Our Increasingly Active Sun
Image Credit & Copyright: Mehmet Ergün

Explanation: Our Sun is becoming a busy place. Only two years ago, the Sun was emerging from a solar minimum so quiet that months would go by without even a single sunspot. In contrast, already this year and well ahead of schedule, our Sun is unusually active, already nearing solar activity levels seen a decade ago during the last solar maximum. Our increasingly active Sun was captured two weeks ago sporting numerous interesting features. The image was recorded in a single color of light called Hydrogen Alpha, color-inverted, and false colored. Spicules carpet much of the Sun's face. The brightening towards the Sun's edges is caused by increased absorption of relatively cool solar gas and called limb darkening. Just outside the Sun's disk, several scintillating prominences protrude, while prominences on the Sun's face are known as filaments and show as light streaks. Magnetically tangled active regions are both dark and light and contain cool sunspots. As our Sun's magnetic field winds toward solar maximum over the next few years, whether the Sun's high activity will continue to increase is unknown.

21/02/2023

ASTRONOMY - Comet ZTF over Yosemite Falls

 2023 February 21

A comet with a green head and extended tails is seen
above a high water fall. In the night sky field just above
the falls, an orange dot -- the star Kochab -- is visible.
Please see the explanation for more detailed information.

Comet ZTF over Yosemite Falls
Image Credit & Copyright: Tara Mostofi

Explanation: They are both falling. The water in Yosemite FallsCaliforniaUSA, is falling toward the Earth. Comet ZTF is falling toward the Sun. This double cosmic cascade was captured late last month as fading Comet C/2022 E3 (ZTF) had just passed its closest to planet Earth. The orange star just over the falls is Kochab. With the exception of a brief encounter with a black bear, the featured image was a well-planned composite of a moonlit-foreground and long-duration background exposures - all designed to reconstruct a deep version of an actual single sight. Although Comet ZTF is now fading as it glides back to the outer Solar System, its path is determined by gravity and so it can be considered to still be falling toward the Sun -- but backwards.

20/02/2023

ASTRONOMY - NGC 1850: Not Found in the Milky Way

 2023 February 20

A ball of yellow stars is seen to the right of blue-glowing
gas filaments. Other blue filaments and foreground stars cover
the frame. 
Please see the explanation for more detailed information.

NGC 1850: Not Found in the Milky Way
Image Credit: NASAESA and P. Goudfrooij (STScI); Processing: M. H. Özsaraç (Türkiye Astronomi Derneği)

Explanation: There is nothing like this ball of stars in our Milky Way Galaxy. This is surprising because, at first glance, this featured image by the Hubble Space Telescope suggests that star cluster NGC 1850's size and shape are reminiscent of the many ancient globular star clusters which roam our own Milky Way Galaxy's halo. But NGC 1850's stars are all too young, making it a type of star cluster with no known counterpart in the Milky Way. Moreover, NGC 1850 is also a double star cluster, with a second, compact cluster of stars visible here just to the right of the large cluster's center. Stars in the large cluster are estimated to be 50 million years young, while stars in the compact cluster are younger still, with an age of about 4 million years. A mere 168,000 light-years distant, NGC 1850 is located near the outskirts of the Large Magellanic Cloud galaxy. The glowing gas filaments across the image left, like supernova remnants in our own galaxy, testify to violent stellar explosions and indicate that short-lived massive stars have recently been present in the region.

19/02/2023

ASTRONOMY - Seven Dusty Sisters in Infrared

 2023 February 19

The field of filamentary dust is shown with different
sections showing different colors. Stars dot the background.
Please see the explanation for more detailed information.

Seven Dusty Sisters in Infrared
Image Credit: NASAWISEIRSAProcessing & Copyright Francesco Antonucci

Explanation: Is this really the famous Pleiades star cluster? Known for its iconic blue stars, the Pleiades is shown here in infrared light where the surrounding dust outshines the stars. Here three infrared colors have been mapped into visual colors (R=24, G=12, B=4.6 microns). The base images were taken by NASA's orbiting Wide Field Infrared Survey Explorer (WISE) spacecraft. Cataloged as M45 and nicknamed the Seven Sisters, the Pleiades star cluster is by chance situated in a passing dust cloud. The light and winds from the massive Pleiades stars preferentially repel smaller dust particles, causing the dust to become stratified into filaments, as seen. The featured image spans about 20 light years at the distance of the Pleiades, which lies about 450 light years distant toward the constellation of the Bull (Taurus).

18/02/2023

SANTé DELICIEUSES HERBES AROMATIQUES - La ciboulette, riche en vitamine K et antioxydants

La ciboulette est une plante aromatique de la famille des Amaryllidacées dont les feuilles, ou brins, sont utilisées comme condiment. Ciselées et crues, ces dernières aromatisent généralement les crudités et les salades mais peuvent également entrer dans certaines recettes telles que des sauces ou des omelettes. La ciboulette relève en finesse tous les plats à base de crème ou de fromage frais. C'est un des ingrédients du « bibalakas » alsacien que l'on sert avec des pommes de terre vapeur ou sautées, du munster et du jambon fumé. La plante est riche en vitamine K et en antioxydants. Elle facilite également la digestion.

© Cyclonebill, CC by-sa 2.0 et Terry Dunn, CC by-nc 2.0
FuturaSciences

ASTRONOMY - Barred Spiral Galaxy NGC 1365 from Webb

 2023 February 18

See Explanation.  Clicking on the picture will download
the highest resolution version available.

Barred Spiral Galaxy NGC 1365 from Webb
Image Credit: NASAESACSA, Janice Lee (NOIRLab) - Processing: Alyssa Pagan (STScI)

Explanation: A mere 56 million light-years distant toward the southern constellation Fornax, NGC 1365 is an enormous barred spiral galaxy about 200,000 light-years in diameter. That's twice the size of our own barred spiral Milky Way. This sharp image from the James Webb Space Telescope's Mid-Infrared Instrument (MIRI) reveals stunning details of this magnificent spiral in infrared light. Webb's field of view stretches about 60,000 light-years across NGC 1365, exploring the galaxy's core and bright newborn star clusters. The intricate network of dusty filaments and bubbles is created by young stars along spiral arms winding from the galaxy's central bar. Astronomers suspect the gravity field of NGC 1365's bar plays a crucial role in the galaxy's evolution, funneling gas and dust into a star-forming maelstrom and ultimately feeding material into the active galaxy's central, supermassive black hole.

17/02/2023

ASTRONOMY - 2023 CX1 Meteor Flash

 2023 February 17

See Explanation.  Clicking on the picture will download
the highest resolution version available.

2023 CX1 Meteor Flash
Image Credit & Copyright: Gijs de Reijke

Explanation: While scanning the skies for near earth objects Hungarian astronomer Krisztián Sárneczky first imaged the meter-sized space rock now cataloged as 2023 CX1 on 12 February 2023 at 20:18:07 UTC. That was about 7 hours before it impacted planet Earth's atmosphere. Its predicted trajectory created a rare opportunity for meteor observers and a last minute plan resulted in this spectacular image of the fireball, captured from the Netherlands as 2023 CX1 vaporized and broke up over northern France. Remarkably it was Sárneczky's second discovery of an impacting asteroid, while 2023 CX1 is only the seventh asteroid to be detected before being successfully predicted to impact Earth. It has recently become the third such object from which meteorites have been recovered. This fireball was witnessed almost 10 years to the day following the infamous Chelyabinsk Meteor flash.

16/02/2023

SANTé - DELICIEUSES HERBES AROMATIQUES - La menthe


Le genre Mentha se compose de plusieurs plantes herbacées de la famille des Labiacées. Celle-ci comprend de nombreuses espèces, dont beaucoup sont utilisées comme plantes aromatiques, condimentaires ou médicinales. C'est la menthe verte qui est la plus fréquemment utilisée comme herbe aromatique dans les cuisines méditerranéenne (thé à la menthe et taboulé) et asiatique (nems). Mais les diverses espèces servent également à la fabrication de sirops, de glaces et de sorbets. Son effet rafraîchissant se retrouve également dans les chewing-gums, les pastilles ou le dentifrice. La menthe poivrée, quant à elle, est essentiellement cultivée pour les besoins pharmaceutiques et en aromathérapie

© Talalosman, CC by-sa 3.0 ; Patrick Alexander, CC by-nc 2.0
FuturaSciences

ASTRONOMY - Mammatus Clouds over Nebraska

 2023 February 12

An unremarkable red building is seen past a large parking lot. 
Above them both are a bank of very unusual clouds with 
many nodules pointing down.
The scene is lit by sunlight from the side. 
Please see the explanation for more detailed information.

Mammatus Clouds over Nebraska
Image Credit & Copyright: Jorn Olsen Photography

Explanation: When do cloud bottoms appear like bubbles? Normally, cloud bottoms are flat. This is because moist warm air that rises and cools will condense into water droplets at a specific temperature, which usually corresponds to a very specific height. As water droplets grow, an opaque cloud forms. Under some conditions, however, cloud pockets can develop that contain large droplets of water or ice that fall into clear air as they evaporate. Such pockets may occur in turbulent air near a thunderstorm. Resulting mammatus clouds can appear especially dramatic if sunlit from the side. The mammatus clouds pictured here were photographed over HastingsNebraska during 2004 June.

15/02/2023

ASTRONOMY - Airglow Sky over France

 2023 February 15

The sky over a picturesque chateau in France is shown featuring
colorful airglow all around. Identifiable in the background night sky 
are objects that include the Orion Nebula, Sirius, Mars, and an 
arching band of our Milky Way Galaxy.
Please see the explanation for more detailed information.

Airglow Sky over France
Image Credit & Copyright: Julien Looten

Explanation: This unusual sky was both familiar and unfamiliar. The photographer's mission was to capture the arch of the familiar central band of our Milky Way Galaxy over a picturesque medieval manor. The surprise was that on this January evening, the foreground sky was found glowing in a beautiful but unfamiliar manner. The striped bands are called airglow and they result from air high in Earth's atmosphere being excited by the Sun's light and emitting a faint light of its own. The bands cross the entire sky -- their curved appearance is due to the extremely wide angle of the camera lens. In the foreground lies Château de Losse in southwest France. Other familiar sky delights dot the distant background including the bright white star Sirius, the orange planet Mars, the blue Pleiades star cluster, the red California Nebula, and, on the far right, the extended Andromeda Galaxy. The initial mission was also successful: across the top of the frame is the arching band of our Milky Way.

14/02/2023

SANTé - DELICIEUSES HERBES AROMATIQUES - Le fenouil


Le terme « fenouil » s'applique à plusieurs taxons distincts de la famille des Apiacées (anc. ombellifères). C'est le fenouil commun que l'on utilise en cuisine. Son goût ressemble à celui de l'anis. On peut cuisiner toutes les parties de la plante : racines, feuilles et graines. On peut le consommer cru, en salade, ou cuit.

Connues depuis l'Antiquité, ses qualités thérapeutiques sont essentiellement carminatives, expectorantes et antispasmodiques.

© Dominique Archambault/jinjian liang, CC by-nc 2.0
FuturaSciences

ASTRONOMY - The Heart and Soul Nebulas

 2023 February 14

Two red emission nebulas are shown in front of a dark
but colorful starfield. The Soul Nebula is on the lower left, while
the Heart Nebula is on the upper right. 
Please see the explanation for more detailed information.

The Heart and Soul Nebulas
Image Credit & Copyright: Juan Lozano de Haro

Explanation: Is the heart and soul of our Galaxy located in Cassiopeia? Possibly not, but that is where two bright emission nebulas nicknamed Heart and Soul can be found. The Heart Nebula, officially dubbed IC 1805 and visible in the featured image on the upper right, has a shape reminiscent of a classical heart symbol. The shape is perhaps fitting for Valentine's Day. The Soul Nebula is officially designated IC 1871 and is visible on the lower left. Both nebulas shine brightly in the red light of energized hydrogen, one of three colors shown in this three-color montageLight takes about 6,000 years to reach us from these nebulas, which together span roughly 300 light yearsStudies of stars and clusters like those found in the Heart and Soul nebulas have focused on how massive stars form and how they affect their environment.

13/02/2023

ASTRONOMY - Comet ZTF and Mars

 2023 February 13

A deep starfield features an orange planet Mars on the left
and a green-headed Comet ZTF on the right. In the foreground
is a landscape that includes the top of a famous mountain 
known as the Matterhorn.
Please see the explanation for more detailed information.

Comet ZTF and Mars
Image Credit & Copyright: Donato Lioce

Explanation: No, Comet ZTF is not going to hit Mars. Nicknamed the Green Comet for its bright green coma, C/2022 E3 (ZTF) did, however, pass almost in front of the much-more distant planet a few days ago, very near in time to when the featured picture was taken. The two sky icons were here captured behind a famous Earth icon -- the Matterhorn, a mountain in the Italian Alps with a picturesque peak. Both the foreground and background images were taken on the same evening by the same camera and from the same location. The comet's white dust tail is visible to the right of the green coma, while the light blue ion tail trails towards the top of the image. Orange Mars is well in front of the numerous background stars as well as the dark nebula Barnard 22 to its lower right. Although Mars remains visible in the evening sky for the next few months, Comet ZTF has already begun to fade as it returns to the outer Solar System.

08/02/2023

ASTRONOMY - Stellar Wind-Shaped Nebula RCW 58

 2023 February 8

A red oval and textured nebula is seen surrounded by a faint
blue glow. A bright star is visible in the center, and many faint
stars are visible in the background. 
Please see the explanation for more detailed information.

Stellar Wind-Shaped Nebula RCW 58
Image Credit & Copyright: Mike Selby & Mark Hanson; Text: Natalia Lewandowska (SUNY Oswego)

Explanation: Imagine traveling to a star about 100 times as massive as our Sun, a million times more luminous, and with 30 times the surface temperature. Such stars exist, and some are known as Wolf Rayet (WR) stars, named after French astronomers Charles Wolf and Georges Rayet. The central star in this image is WR 40 which is located toward the constellation of Carina. Stars like WR 40 live fast and die young in comparison with the Sun. They quickly exhaust their core hydrogen supply, move on to fusing heavier core elements, and expand while ejecting their outer layers via high stellar winds. In this case, the central star WR 40 ejects the atmosphere at a speed of nearly 100 kilometers per second, and these outer layers have become the expanding oval-shaped nebula RCW 58.

SANTé/MEDECINE - Virus et bactéries mortels - Le virus de la rage

Grâce aux travaux de Louis Pasteur , la rage a très nettement reculé dans le monde. On dénombre tout de même plus de 50.000 morts humains s...