ASTRONOMY - Our Increasingly Active Sun

 2023 February 22

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.

ASTRONOMY - Comet ZTF over Yosemite Falls

 2023 February 21

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

Explanation: They are both falling. The water in Yosemite Falls, California, USA, 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.

ASTRONOMY - NGC 1850: Not Found in the Milky Way

 2023 February 20

NGC 1850: Not Found in the Milky Way
Image Credit: NASA, ESA 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.

ASTRONOMY - Seven Dusty Sisters in Infrared

 2023 February 19

Seven Dusty Sisters in Infrared
Image Credit: NASA, WISE, IRSA, Processing & 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).

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

Barred Spiral Galaxy NGC 1365 from Webb
Image Credit: NASA, ESA, CSA, 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.

ASTRONOMY - 2023 CX1 Meteor Flash

 2023 February 17

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.

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

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 Hastings, Nebraska during 2004 June.

ASTRONOMY - Airglow Sky over France

 2023 February 15

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.