N79 is a nebula, a kind of large cloud of gas and dust propitious to star formation. 

This little-known region in the Large Magellanic Cloud (a galaxy close to our own, the Milky Way) has a particularly rapid star formation rate, much faster than the star-forming regions of our galaxy. 

What explains this speed is the nebula's chemical composition: it's similar to that of the early univers, when star formation was at its peak! 

It was observed with the James Webb Space Telescope in the mid-infrared (between 2.5 and 5 micrometers, mid-infrared is absorbed by the water vapour in our atmosphere, which protects us from this radiation). 

These observations reveal bright gas and dust at the heart of the clouds, encrusted with newborn stars, including a very bright young star in the center of the image, shining through layers of gas clouds. 

Credits: ESA / Webb - NASA and CSA - O. Nayak - M. Meixner

This image was taken in Normandy, northern France, above Mont Saint-Michel, by Mathieu Rivrin on the night of May 10-11.

It illustrates the aurora borealis observed in a large part of the northern hemisphere. We are currently, in 2024-2025, in a period of very high solar activity, which recurs cyclically every 11 years. As solar eruptions are extremely strong and exceptional, it is possible to observe beautiful pinkish colors in the sky, due to the collision of solar particles and oxygen present in the upper atmosphere (300km).
For more details on this magnificent phenomenon, please read the following article: The Northern lights

Credits: paris-normandie.fr/

As part of its research into protoplanetary disks (disks of matter around stars that eventually form planets over millions of years), Hubble studied HP Tau, a triple star system located in a reflection nebula, around 550 light-years from Earth, in the constellation Taurus. 
The system is made up of three stars: HP Tau, HP Tau G2, and HP Tau G3.
HP Tau is a variable T Tauri star, which are young stars still in formation, generally less than 10 million years old, unlike our Sun, which is around 4.6 billion years old.
They have not yet begun hydrogen nuclear fusion, but are in the process of transforming into stars similar to our Sun.
These stars are often surrounded by clouds of dust and gas, the residue of their formation.
The nebula surrounding HP Tau is illuminated by the light of nearby stars - a reflection nebula. 
Reflection nebulae don't produce their own light, but shine thanks to the reflection of starlight off dust and gas particles, rather like fog illuminated by car headlights.

Credit: science.nasa.gov

This photo, taken earlier this week, shows a new solar flare. These regular plasma ejections from our star are a sign of high solar activity. Indeed, when the Sun is undergoing high activity, it ejects a greater quantity of plasma, and it's these plasma ejections by the Sun that draw its well-known brown spots.
When such spots appear, astronomers can estimate a certain probability of seeing aurora borealis in the coming days. This is because solar flares eject large quantities of plasma and highly-charged solar particles which, when they move in our direction, cause the aurora borealis when they come into contact with our atmosphere. For more details on the aurora borealis, read : The "image of the week" 2 : the northern lights

With the active region aligned on the Earth's axis as it rotates around the Sun, astronomers have concluded that we may yet be able to enjoy majestic auroras in the coming weeks, similar to those we already witnessed on May 11 and 12 during one of the greatest geomagnetic storms of recent decades.
Such exceptional events with such frequency are not a sign of the end of the world, but are simply symptoms of peaks in solar activity, which recur approximately every 11 years. To find out more, read the article dedicated to this topic: The Northern lights

Credit : NASA's GSFC, SDO AIA Team 

The Lynds Dark Nebula

LDN 1251 is a dark nebula in the constellation Cepheus, characterized by dense dust clouds that block out the light from background stars. It is notable for its jets of Herbig-Haro objects, signs of young stars in formation, and its complex filaments of dust and gas, making it a key site for the study of star formation and interstellar interactions. 
In astronomy, Herbig-Haro objects (sometimes abbreviated to HH objects) are small nebulosities associated with certain very young stars, which form when matter ejected by these stars collides with the surrounding clouds of gas and dust, at speeds of several hundred kilometers per second. Herbig-Haro objects are ubiquitous in star-forming regions, and it is often possible to observe several of them around the same star, aligned along its axis of rotation.
These objects are ephemeral phenomena, with a lifespan of a few thousand years at most. It is possible to see them evolve over a relatively short period of time, as they move away from the star from which they originate through clouds of interstellar gas. Observations by the Hubble Space Telescope show complex evolutions over just a few years, with some parts fading while others brighten, depending on the density of the medium encountered.

Credit: Long Xin - nasa.gov

Located more than 430 light-years from Earth, J1407b is a spectacular exoplanet, orbiting a star similar to our own young sun. Spotted in 2012 by a group of American and British astronomers, this exoplanet (planet outside our solar system) was the first to be discovered with Saturn-like rings. These rings were discovered thanks to the observation of a variant luminosity of the star J1407 around which the planet orbits. As it passed in front of its star, J1407b obstructed the Earth's view of its light for some time, and did so repeatedly, like a series of mini-eclipses with different intensities, each time a ring passed in front of the star. 
J1407b's rings are similar to Saturn's in many regards, but they are nonetheless more than 200 times larger. They are composed of dust and residue, orbiting the planet. The origin of the rings is the source of many hypotheses, and this planet remains one of the magnificent mysteries of our universe.

Credit: https://www.nationalgeographic.fr/

On the occasion of its 2nd anniversary, the James Webb Space Telescope presented us with a magnificent image. Arp 142, or the Penguin and the Egg, is a scene showing a pair of interacting galaxies, located around 326 million light-years from Earth in the Hydra constellation. These galaxies have been observed before, but never in such detail as JWST has permitted. The James Webb Space Telescope is a space observatory, which observes the universe mainly under infrared light. It was launched on December 25, 2021, with the aim of better understanding the formation and evolution of bodies in the universe, exploring distant worlds and trying to determine whether life exists on exoplanets orbiting stars. It is the result of work by NASA in collaboration with ESA and CSA (the Canadian Space Agency), and it was on July 12, 2022 that JWST unveiled its first images, 2 years ago now. 

Credit : Space.com / jwst.fr

NGC 6946, also known as the Fireworks Galaxy, is a beautiful spiral galaxy located just 20 million light-years away, behind a veil of dust and stars in the far-off constellation Cepheus.

Credit : nasa / Roberto Marinoni (image)

NGC 7023, also known as the Iris Nebula, is a reflection nebula, meaning that the cloud of gas and light doesn't produce its own light, but shines by reflecting the light of nearby stars. In contrast to emission nebulae, reflection nebulae often appear blue, as dust more easily scatters blue starlight. 

The Iris Nebula is located around 1,300 light-years from Earth, in the constellation Cepheus. It is illuminated by the hot young star SAO 19158, whose light is reflected by the surrounding dust clouds, giving the nebula its characteristic blue glow.

This nebula is a star-forming site, with very dense zones where stars can form, and measures around 6 light-years in diameter.

Image and text credit : Robert Shepherd / nasa.gov

Above is the image of the most distant galaxy ever observed to date. This galaxy, JADES GS-z14-0, is one of the discoveries made as part of the JADES (JWST Advanced Deep Extragalactic Survev) program, a scientific collaboration that uses the James Webb telescope to observe the distant universe, and in particular the first galaxies formed after the Big Bang. The main aim of the JADES program is to make deep observations of galaxies that are very far away, and therefore also very old (because looking far into space is like looking far back in time: sunlight takes 8 minutes to reach us, for example, so we see it as it was 8 minutes ago), using the JWST's infrared capabilities to see objects that have remained undetectable by other telescopes. For more discoveries about this incredible galaxy, I refer you to my article : JADES GS-z14-0: the universe's most distant galaxy ever observed

Image credit : NASA, ESA, CSA, STScI, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Phill Cargile (CfA)

This year, in addition to the Perseids, August's flagship event, magnificent northern lights participated in adorning the summer sky. In fact, with the sun at its peak (see article on the aurora borealis : The Northern lights), it's becoming less and less rare to observe auroras as far south as the Northern Hemisphere. After the sun's recent emission of charged particles, these came into contact with our atmosphere, descending as far as Texas and Italy, leaving behind a colorful night sky already dotted with meteors. 
The photograph above was built up from 7 exposures, taken over 26 minutes from Ense, Germany.

Image credit : Chantal Anders, NASA

“When can you see a black hole, a tulip and a swan at the same time? At night, if the time is right and your telescope is pointed in the right direction .” (NASA) In the constellation Cygnus, 8,000 light-years from Earth, lies this magnificent and impressive Tulip Nebula, a region favorable to star formation. It is illuminated by young, hot stars, in particular HD 227018, whose ultraviolet radiation ionizes the surrounding hydrogen gas (= chrarge into electricity), causing its reddish luminescence. In the same field of view as the nebula, we can also observe the black hole Cygnus X-1, one of the most powerful sources of X-rays in our sky. This source is such that Cygnus X-1 can be described as a microquasar, but such a black hole is officially called an X-ray binary. In fact, Cygnus X-1 is a stellar black hole (i.e. small, with a mass of around 20 solar masses), associated with a blue supergiant star, HDE 226868. The black hole, with a mass of around 21 solar masses, attracts matter from its companion star. This matter forms an accretion disk around the black hole, emitting intense X-rays when heated to extreme temperatures as it approaches the black hole. This is what we call an X-ray binary, and it remains a much smaller object than a quasar (hence the name microquasar! :) ).

Image credit : Anirudh Shastry

This week, I'm honored to present the first itw (image of the week) photographed by hand.

The Moon, our fabulous satellite, our eternal protector, the dream of all of us who look up to the sky.  

I photographed it using my meagre resources, through the 12.5 mm eyepiece of my Meade 231 telescope , with a focal length of 700mm and a diameter of 60mm, with the camera on my phone.

I took this photo on September 15, 2024, around midnight. 

I particularly like it because, as the Moon is not yet full, it's easy to make out the various craters on our satellite, which stand out against the shadows. 

In this zoomed-in photograph, the Copernicus and Tycho craters are clearly visible at the top and bottom of the image respectively.  The Mare Cognitum, a grey patch between the two craters, is also clearly visible.

This image is one of my first, and just the beginning of a long line. 

You'd hardly recognize the Pleiades cluster, nicknamed the Seven Sisters cluster and catalogued as M45; this group of 7 iconic blue stars.

Photographed under infrared light, the Pleiades cluster is positioned by coincidence at the heart of a dust cloud, which, made visible by infrared observation, eclipses the cluster's stars.

3 infrared colors have been transcribed into visible colors to make them appear to our eyes, in red, green and blue on the image.

The surrounding dust adopts strange shapes, like cotton threads, due to the light and wind of the Pleiades' massive stars, which pushes away the smallest dust particles.

Image credit : WISE, IRSA, NASA, Processing & copyright : Francesco Antonucci

Around 600 light-years from our planet, in the Cassiopeia constellation, clouds IC 59 (left) and IC 63 (right) stand like two radiant ghosts. The categorization “IC” stands for the “Index Catalogue”, which complements the “New General Catalogue” (= NGC, a title you've no doubt often heard when talking about astronomical objects), and lists a further 5,286 galaxies, nebulae and star clusters discovered between 1888 and 1907. These two magnificent pink ghosts are slowly fading away, due to the energetic radiation of the hot star Gamma Gas, located 3 or 4 light-years away from our nebulae. IC 63 is slightly closer to the hot star Gamma Gas, and is therefore dominated by the red light emitted by hydrogen atoms ionized (=charged) by the star's radiation. IC 59 is further away from the star and therefore less influenced by its radiation, giving it a rather bluish color, the result of the reflection of the star's blue light by the cloud's gas and dust particles. 

Image credit : Christophe Vergnes

The Lagoon Nebula, catalogued as Messier 8 (M8) is a giant interstellar cloud in the constellation Sagittarius. It is classified as an emission nebula and has an H II region. (An emission nebula is a nebula formed of ionized gases (charged gases) that emit light of various wavelengths. The most common source of ionization is high-energy ultraviolet photons emitted from a nearby hot star. A H II region is a region of interstellar atomic hydrogen that is ionized.) The Lagoon Nebula is an immense cloud of hydrogen and dust illuminated by the star 9 Sagittarii. It's a binary star system made up of two blue giants whose luminosities are respectively 316,000 and 562,000 times that of the Sun.

Image credit : Josep Drudis, Christian Sasse & source : wikipedia

With cold weather and winter fast approaching, this week I'm introducing THE star constellation of this time of year, a shot that's both classic and timeless in astrophotography : the Orion nebula. One of the best-known and most spectacular nebulae, but also one of the most accessible for observation. Located some 1340 light-years from Earth, it is the nebula most visible to the naked eye from the northern hemisphere. 

Image credit : Fényes Lorand

This spectacular and dark scene brings to light our former planet of the solar system: Pluto, a resident of the Kuiper Belt, a donut-shaped zone located just beyond Neptune's orbit, which contains most of the dwarf planets and some comets. This image shows the night side of the dwarf planet, with the Sun positioned about 4.9 billion kilometers behind Pluto. It was taken by the New Horizons probe in 2015, with the main goal of exploring Pluto and its moons, now located approximately 60 AU (astronomical units) away from us, or around 9 billion kilometers. In this picture, the crescent-shaped twilight zone reveals plains of nitrogen ice and mountains of water ice, key features of Pluto’s surface.

Image credit : NASA

This week, here is the Ring Nebula, also one of the most prominent images captured by the JWST. This magnificent nebula, as if the eye of the universe is watching us, is located over 2,000 light-years away in the constellation Lyra. It has an apparent magnitude of 8.8, which makes it an easy object to find with good equipment, and its observation is optimal in August, when Lyra dominates the summer sky. The Ring Nebula is a planetary nebula, meaning a celestial body that, when observed with low-resolution equipment, resembles a planet or a nebulous disk. This nebula, classified as M57, is the stunning remnant of a Sun-like star, whose gases, ejected several thousand years ago, now appear to us in the form of a remarkable ring. In the center of the ring, there is a white point—the hot core of the star, also known as a white dwarf.

Image copyright credit : NASA, ESA, CSA, JWST. Processing : Zi Yang Kong

How can one not talk about the nebula that adorns the homepage of my website? The Horsehead Nebula, one of the most recognizable nebulae in the sky, is located in the constellation of Orion. It is also one of the most famous, appreciated, and outstanding constellations of our winter night sky. This horsehead-shaped nebula is only a small part of an immense dark molecular cloud. The red light that lines the background of the image is mostly due to the presence of hydrogen gas located just behind the nebula, ionized by a bright nearby star, while the Horsehead’s obscurity is caused by a thick layer of dust.

Image credit : Alex Lin (Chilescope)

In anticipation of an absolutely incredible article that will be coming very soon to my website (please accept my self-promotion :) ), I’m sharing this week a stunning image of the Large Magellanic Cloud, sometimes referred to by its acronym LMC. It is the closest celestial object to us that does not belong to our Milky Way galaxy. The Large Magellanic Cloud is a satellite galaxy of ours, located about 163,000 light-years from Earth. It contains hundreds of millions of stars, nebulae, and star clusters. We can easily recognize it by its irregular shape, probably due to gravitational interactions with our galaxy. But the LMC is not just the closest galaxy to ours. It is also one of the only celestial objects visible from Earth that lies outside our galaxy. It’s fascinating to think that almost all the stars we observe at night from our home are just stars from our own galaxy, and in the end, we don’t see any further than the tip of our nose.

Image credit : John Davis

After the Large Magellanic Cloud, here comes the Small Magellanic Cloud (SMC), the 2nd closest galaxy to ours. 

Image credit : nasa.gov

This galaxy stands out for its remarkable visibility of stars. In the spiral galaxy NGC 300, an extraordinary number of bright blue stars are clustered into easily distinguishable groups, making them prominent in this deep-space image. Its exceptional clarity is also due to its proximity to Earth — light from NGC 300 travels only about 6 million years to reach us. Despite the abundance of bright stars, most of a galaxy’s stars are faint, and its overall mass is dominated by dark matter, which remains invisible. (Go check the article about dark matter: Dark matter ) NGC 300 can be observed with a small telescope in the southern constellation of Sculptor. This striking composite image was taken in October from Rio Hurtado, Chile, by Daniel Stern. 

Image credit : Daniel Stern 

Text inspiration : nasa.gov