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Nereide @drnereide.bsky.social · 1h

A circumhorizontal arc (or circumhorizon arc) is a rare phenomenon because the Sun has to be 58° high or greater, there must be high altitude cirrus clouds with flat ice crystals, lastly sunlight has to enter the ice crystals at a specific angle.

Learn more➡️ www.atoptics.co.uk/blog/circumh...

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Circumhorizon Arc

This article explores the characteristics, visibility, and geographic distribution of the circumhorizon arc, a stunning optical phenomenon often mistaken for a fire rainbow. It discusses how to distin...

www.atoptics.co.uk

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Nereide @drnereide.bsky.social · 1h

The ice halo is formed by sunlight entering horizontally-oriented hexagonal, plate-shaped ice crystals in cirrus clouds, in this case cirrus fibratus clouds.

The halo is so wide that the arc appears parallel to the horizon, thus the name.

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Nereide @drnereide.bsky.social · 1h

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A nice circumhorizontal arc (informally known as a fire rainbow, which is a misnomer) over West Virginia captured by Christa Harbig!

It is an optical phenomenon belonging to the family of ice halos, so it is neither fire nor a rainbow.

➡️ apod.nasa.gov/apod/ap21083...

🔭 🧪 #science

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$The image shows a circumhorizon arc (or circumhorizontal arc), an optical phenomenon resembling a fiery rainbow. It forms in a clear sky with cirrus clouds made of flat, hexagonal ice crystals aligned horizontally. These crystals refract sunlight, creating a colorful arc parallel to the horizon. Vibrant colors shine brightly against the blue sky, captured near North Fork Mountain, West Virginia.$

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Reposted by Nereide

Nereide @drnereide.bsky.social · 1d

"The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars.
We are made of starstuff."

— Carl Sagan. Cosmos (1980).

Image source➡️ imagine.gsfc.nasa.gov/news/10sep08...

🔭 🧪 #science

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The image is an artist's illustration of one model of the bright gamma-ray burst GRB 080319B.
The explosion appears highly beamed into two bipolar jets, with a narrow inner jet (white) surrounded by a wider outer jet (green).

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Reposted by Nereide

Dr Elodie Chabrol @eloscicomm.bsky.social · 13h

Ça fait VRAIMENT TOUT DRÔLE de recevoir mes affiches CASIO Women Do Science ! 🥰 🤯
Tellement fière de faire partie de cette initiative !

🔗Découvrez ma page et téléchargez le poster ici lnkd.in/ejrpYndE
PS : Plume a validé les posters... mais a clairement refusé de recréer la pose 🐾

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Nereide @drnereide.bsky.social · 13h

enriching it with heavy elements, which contributes to the chemical enrichment of galaxies.

In other words, supernovae produce the elements that make up everything around us, including us.

So, yes, we are grateful to those distant stars: without their "deaths," we wouldn't exist!

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Nereide @drnereide.bsky.social · 13h

Yes, it is. When iron accumulates in the core of a massive star, energy generation through nuclear fusion finishs.

This leads to rapid gravitational collapse, followed by a supernova explosion. Supernovae pour the products of explosive nucleosynthesis into the interstellar medium,

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Nereide @drnereide.bsky.social · 1d

The quote “We are stardust, billion year old carbon” is from Joni Mitchell’s song Woodstock, though Crosby, Stills, Nash & Young’s cover made it iconic. :)

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Nereide @drnereide.bsky.social · 1d

You’re right, the bright star cluster does look like a reflection on the Bubble Nebula’s surface. The cosmos is really stunning.

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Nereide @drnereide.bsky.social · 1d

You're welcome!

Nereide @drnereide.bsky.social · 1d

Image description: Artist's illustration of one model of the bright gamma-ray burst GRB 080319B.
The explosion is highly beamed into two bipolar jets, with a narrow inner jet surrounded by a wider outer jet.
(More at the link above)

Image credit: NASA/Swift/Mary Pat Hrybyk-Keith and John Jones

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Nereide @drnereide.bsky.social · 1d

"The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars.
We are made of starstuff."

— Carl Sagan. Cosmos (1980).

Image source➡️ imagine.gsfc.nasa.gov/news/10sep08...

🔭 🧪 #science

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Reposted by Nereide

Nereide @drnereide.bsky.social · 2d

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In this fascinating image by Russel Croman you can admire a stunning 3D effect of NGC 7635: the Bubble Nebula, an H II region emission nebula in Cassiopeia.

➡️ apod.nasa.gov/apod/ap05110...

The "bubble" is generated by the stellar wind from the...

🔭 🧪 #science

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The image shows NGC 7635, the Bubble Nebula. It is a 10-light-year gas sphere, pushed by the stellar wind of star BD+602522. To the lower right, a giant molecular cloud glows, heated by the star’s radiation. Shown in scientifically mapped colors to enhance contrast, it’s part of a larger star and shell complex, visible with a small telescope toward Cassiopeia.

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Reposted by Nereide

Nereide @drnereide.bsky.social · Sep 3

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An interesting study shares JWST breathtaking images of a protoplanetary disk seen edge-on around the protostar IRAS04302+2247, still nestled in its birth cloud.

The young star is located 525 ly away in the Taurus star-forming region.

Image Credit: ESA/Webb, NASA & CSA, M. Villenave et al

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"A wide-field image of IRAS 16594-4656 taken by the James Webb Space Telescope. The nebula’s bright core is split by a narrow dark band, with expansive rainbow lobes of light and colour radiating outward. Numerous background galaxies and stars are visible across the field."
From the press release.

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Nereide @drnereide.bsky.social · 2d

The Bubble Nebula isn’t a bubble that can pop. It’s a stable gaseous orb, shaped by the stellar wind from a massive central star. The wind’s pressure maintains its form, but it won’t burst like a soap bubble. It’s a steady cosmic feature, visible in Cassiopeia.

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Nereide @drnereide.bsky.social · 2d

A molecular cloud is a type of interstellar cloud where the density and temperature allow the formation of molecular hydrogen (H2) from individual hydrogen atoms.

Molecular clouds are the prime location for the birth of new stars.

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Nereide @drnereide.bsky.social · 2d

massive central star, SAO 20575 (BD+60°2522).

NGC 7635 is close to a giant molecular cloud that contains the expansion of the bubble gas.

The dense molecular cloud itself is excited by the radiation from the hot central star and glows.

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Nereide @drnereide.bsky.social · 2d

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In this fascinating image by Russel Croman you can admire a stunning 3D effect of NGC 7635: the Bubble Nebula, an H II region emission nebula in Cassiopeia.

➡️ apod.nasa.gov/apod/ap05110...

The "bubble" is generated by the stellar wind from the...

🔭 🧪 #science

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Reposted by Nereide

Nereide @drnereide.bsky.social · 3d

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The Nobel Prize in Physics 2025 has just been awarded to John Clarke, Michel H. Devoret, John M. Martinis

“for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit.”

🧪 ⚛️ #science #NobelPrize2025 #physics

The image is an illustration of the three Nobel laureates in physics, from left to right: John Clarke, Michel H. Devoret, and John M. Martinis.

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Nereide @drnereide.bsky.social · 3d

More at the official Nobel Prize press release➡️ nobelprize.org/prizes/physi...

Credit: Illustrations by Niklas Elmehed, via #NobelPrize

Nobel Prize in Physics 2025

The Nobel Prize in Physics 2025 was awarded to John Clarke, Michel H. Devoret and John M. Martinis “for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electri...

nobelprize.org

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Nereide @drnereide.bsky.social · 3d

Their work, by facilitating the understanding of quantum mechanics on a macroscopic scale, has opened possibilities for next-generation quantum technologies, such as quantum cryptography, computers, and sensors.

The prize is shared equally among the three laureates.

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Nereide @drnereide.bsky.social · 3d

Their experiments, realized in 1984-1985 using a superconducting circuit with a Josephson junction, demonstrated quantum effects, like tunnelling and quantised energy levels, in a system large enough to be held in hand.

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Nereide @drnereide.bsky.social · 3d

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The Nobel Prize in Physics 2025 has just been awarded to John Clarke, Michel H. Devoret, John M. Martinis

“for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit.”

🧪 ⚛️ #science #NobelPrize2025 #physics

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Reposted by Nereide

Nereide @drnereide.bsky.social · 5d

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This spectacular image, by team ARO (astroaro.fr/en/home/), shows the Flame Nebula designated as NGC 2024.

It is an emission nebula located some 1,500 light-years away towards the constellation of Orion.

➡️ apod.nasa.gov/apod/ap21041...

🔭 🧪 #science

The image features the nice Flame Nebula (NGC 2024), located 1500 light-years away towards the constellation of Orion. It resembles a a blazing fire, with dark dust lanes on the left. The bright star Alnitak, on the far left, lights up the nebula, making the hydrogen gas clouds shine. The image combines three visible color bands and a long exposure in hydrogen light, revealing details. The Flame Nebula is part of the Orion Molecular Cloud Complex.

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Nereide @drnereide.bsky.social · 5d

opens a universe of discoveries!

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