iiinova — where your digital self keeps evolving

Simons Observatory @simonsobservatory.org · 18/09/2026

We wish a particularly good Dieciocho to our incredible site team who also run a nice Instagram account with site pictures www.instagram.com/simons_obser...

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Instagram

Create an account or log in to Instagram - Share what you're into with the people who get you.

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Simons Observatory @simonsobservatory.org · 22/07/2026

Tomorrow evening at 8pm! Come hang out with us, Ontarians! www.astro.utoronto.ca/astrotours/i... Or ask our panelists questions using this form: l1nq.com/j98p21e 🔭

astro.utoronto.ca

Home | AstroTours

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Simons Observatory @simonsobservatory.org · 20/07/2026

Or even better, if you are able, come ask them questions at an outreach event this Thursday (July 23rd) evening at 8pm! McLennan Physical Laboratories, 255 Huron St, Toronto www.astro.utoronto.ca/astrotours/

astro.utoronto.ca

Home | AstroTours

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Simons Observatory @simonsobservatory.org · 20/07/2026

Time for our annual meeting at U Toronto! Do you have any questions for the astrophysicists there? #astronomy

A phototgraph of people seated in a lecture theater with laptops in front of some of them while a few people are on the stage showing a video projected on a screen.

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Department of Physics at the University of Oxford @oxfordphysics.bsky.social · 29/06/2026

Join the @simonsobservatory.org astrophysicists (Oxford group) at the @royalsociety.org Summer Science Exhibition (30 June–5 July) on Stand 3. Book free tickets at royalsociety.org and share your photos tagging us and #SOonTour 🌌

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Simons Observatory @simonsobservatory.org · 15/07/2026

Many SO members as students or instructors!

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Gabe Lynch @gpxl.bsky.social · 15/05/2026

27, 39, 93, 145, 225, 280 GHz

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Simons Observatory @simonsobservatory.org · 13/05/2026

Happy 60th birthday to physicist Uroš Seljak, born on 13 May 1966 in Slovenia, who coined the term "B-mode" and figured out with others that we could probe the era of inflation with the Cosmic Microwave Background in 1996-1997. 30 years later, we (and others) are on the hunt for them!

A series of swirly black lines are overlaid on a blue-green background with a yellow band in the middle, distorting it. This image won a 2019 wikimedia competition for science images. Uros' explanation:

"Scientists believe our Universe started with a rapid expansion, during which tiny quantum seeds were imprinted into the fabric of spacetime, leading in time to creation of galaxies, stars and planets, including the Earth. To prove this theory scientists are searching for B-modes, a spiral type of polarization imprinted in the microwave sky. However, Milky Way emits dust, which is also polarized, and scientists must learn how to distinguish the two signals.

This image was created by taking dust emission as measured from the Planck satellite and converting its intensity into a polarization pattern. The bright yellow band is Milky Way as seen in the microwave sky. A B-mode was imprinted into a single spot by locally rotating the dust polarization pattern by 45 degrees. A hilly landscape was added at the bottom to represent that many of the B-mode experiments are ground based, in places from Antarctica to Atacama desert in Chile.

This picture is a great example of a teamwork in science and could not have been made without the input of numerous people. Special thanks to the Planck satellite team who observed and made public the data this is based on, Susan Clark for the original inspiration, Yu Feng for the data processing and Andrej Berlot for the post-processing. "

A photograph, seen from behind and under, an SO Small Aperture Telescope (SAT) is pointing at the night sky. It is a white cylinder attached to a mount and partly covered by a tarp. A large vertical jackscrew controls the elevation orientation of the telescope. Thick red cables can be seen exiting from the side of the telescope at the edge of the image.

Uros Seljak, standing behind a podium speaking into a microphone. He is a White man with brown hair and greying temples wearing a dark grey suit, a white shirt and a blue-grey tie. Behind him are three flags: EU, Slovenian, and the University of Ljubljana.

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Simons Observatory @simonsobservatory.org · 21/04/2026

Congrats to Simons Observatory members Colin Hill and @msyriac.bsky.social for receiving the Breakthrough New Horizons Prize in Physics for work on CMB lensing! Our LAT is raring to go and image the gravitational lensing of the CMB deeper than ever before! (Credit: SO/O. Kusiak/K. Perez Sarmiento)

A map of blobs in grayscale, that correspond to the gravitational lensing measured by the SO LAT in a small part of the sky (the edges of the image give the dimensions in degrees. The whole patch is roughly 15x45 degrees

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NSF–DOE Rubin Observatory @rubinobservatory.org · 13/03/2026

How many viscachas is too many? Answer: more than we can fit here—because this still isn’t enough! 🐾 These fluffy mountain summit residents have been hopping, sunbathing, and keeping an eye on us while NSF–DOE Rubin Observatory captures the cosmos! 🔭🧪

Two fluffy rodents with long ears and bushy tail among rocks in golden sunset light

Two fluffy rodents with long ears and bushy tail on rocks.

Four fluffy rodents with long ears and bushy tail among grass and rocks.

A fluffy rodent with long ears and bushy tail among rocks looks at the camera

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Simons Observatory @simonsobservatory.org · 13/03/2026

Are you, or do you know a student, who would be interested in a one-week summer school on the cosmic microwave background? The @simonsfoundation.org is organising one this July in NYC, with accommodation and travel support available! Apply by April 4th here: www.simonsfoundation.org/event/cmb-su...

simonsfoundation.org

2026 Flatiron Institute CMB Summer School

2026 Flatiron Institute CMB Summer School on Simons Foundation

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Simons Observatory @simonsobservatory.org · 10/03/2026

POV: You're an observatory 🔭 in a remote part of the world but somehow aren't worried about this whole "oil price spike" thing. An important part of our Advanced Simons Observatory grant was to make our observatory mostly #SolarPowered Image credit: Dr Benjamin Schmitt, U Penn

The photovoltaïc array of the Simons Observatory nearly complete in the Atacama Desert. Mountains are visible in the distance of the earthy landscape, small clouds drift in the blue sky above.

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Simons Observatory @simonsobservatory.org · 26/02/2026

Our Large Aperture Telescope making friends last December.🧪🔭 Nuestro Telescopio de Gran Apertura haciendo un amigo el pasado diciembre. Image Credit: Federico Nati

A yellow-orange vicuna (kind of looks like a miniature lama) stands in the foreground of a white structure in a rocky landscape. The structure has two parts: a U-shaped part, to which is attached a rectangular box with one side open. The box part looks like it can rotate on its attachement axis.

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Simons Observatory @simonsobservatory.org · 26/02/2026

The Northeastern US wasn't the only place with snowfall last weekend... It also snowed at our site, nestled at 5200m above sea level in the Atacama desert! ¡El fin de semana pasado nevó en nuestro observatorio, situado a 5200 m sobre el nivel del mar en el desierto de Atacama!🔭 Image: Niklas Tampier

Steps in the snow. In the background, some funnel-like structures can be seen set against a blue sky.

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Simons Observatory @simonsobservatory.org · 19/12/2025

On the sixth day of CMBmas my telescope gave to me: Six SATs a-funding FIVE SCORE PAPERS Four parts of Stokes Three fine SATs 🔭 Two optics designs and a low PWV We have a new paper out, presenting how we are expanding the SAT side of SO, to detect B-modes ever better. arxiv.org/abs/2512.15833

A timeline of the SAT construction and operations. A box reads: "SAT science: Searching for the signature of primordial gravitational waves generated in the early Universe"
The timeline indicates 3 SATS/36000 detectors observing from 2024 to 2027, and 6 SATs/62000 detectors from 2027 to 2035. Four of the SATs are labelled 90/145GHz, one is labelled 225/280GHz, one 27/39GHz. The uncertainty on r (sigma r) drops to 0.001 in 2035, compared to 0.003 in 2028.

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Simons Observatory @simonsobservatory.org · 19/12/2025

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Simons Observatory @simonsobservatory.org · 18/12/2025

On the fifth day of CMBmas my telescope gave to me: FIVE SCORE PAPERS Four parts of Stokes Three fine SATs 🔭 Two optics designs and a low PWV We have already published more that 100 papers describing the instruments and forecasting their performance! See them at that link:

ui.adsabs.harvard.edu

Astrophysics Data System

A powerful, streamlined new Astrophysics Data System

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Simons Observatory @simonsobservatory.org · 18/12/2025

ui.adsabs.harvard.edu

Astrophysics Data System

A powerful, streamlined new Astrophysics Data System

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Simons Observatory @simonsobservatory.org · 18/12/2025

On the fourth day of CMBmas, my telescope gave to me: Four Stokes components Three working SATs 🔭 Two optics designs and a low PWV Any light can be decomposed into the four so-called Stokes parameters: total intensity I, two linear polarizations Q and U, and circular V. SO measures I, Q and U.

A diagram illustrating the three possible polarizations of light. The x and y axes of an electrical field are labelled in black. For light coming out of the screen towards you, the linear polarization Q, in red, makes a + cross shape along those x and y axes, U, in blue, is rotated by 45° and makes an x shape. A green circle with two arrows on it attempts to represent circular polarization V.

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Simons Observatory @simonsobservatory.org · 18/12/2025

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Simons Observatory @simonsobservatory.org · 17/12/2025

On the third day of CMBmas, my telescope gave to me: Three working SATs 🔭 Two optical designs and a low PWV Last winter, we fixed a cracked lens in one of our Small Aperture Telescopes. We put it back on its' platform and it's now scanning the sky again. (Timelapse made by Josh Borrow, UPenn)

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Simons Observatory @simonsobservatory.org · 17/12/2025

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Simons Observatory @simonsobservatory.org · 15/12/2025

On the second day of CMBmas, my telescope gave to me: Two optical designs 🔭🧪 and a low PWV We are fielding both refractors and a reflector in the Atacama Desert, (see our two previous threads for explainers!) bsky.app/profile/simo... bsky.app/profile/simo... Image credit: Elle Shaw

A view of the Atacama desert on the shoulder of a mountain. In the foreground, the SO LAT stands, like a 10m tall searchlight painted white. In the background, on the left, some big upturned funnels can be seen: they shield our delicate SATs from having to see the mountain.

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Simons Observatory @simonsobservatory.org · 15/12/2025

On the first day of CMBmas, the observatory Had a low PWV Telescopes like us are inconvenienced by water in the atmosphere emitting/blocking microwaves (same reason why a microwave heats food well). Luckily, the #Atacama desert has one of the lowest Precipitable Water Vapour amounts Earth.

A Mercator map of the world with the countries outlined. The map is mostly white, but Greenland, Tibet, the Andean Plateau and Antarctica are colored in various shades of blue. The legend indicates this means lower amounts of precipitable water vapor. The color scale goes from 0 to 5, with antarcitca the closest to 0, Greenland , Chile and Tibet sit between 1 and 2.5

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Eve Vavagiakis @evevavagiakis.bsky.social · 03/11/2025

Thrilled to join the Simons Observatory with Duke University as a member institution! @simonsobservatory.org today.duke.edu/2025/10/capt...

today.duke.edu

Capturing the Big Bang’s Afterglow | Duke Today

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Simons Observatory @simonsobservatory.org · 05/09/2025

UK people! If you tune in to BBC Four at 22:00 BST this Monday, you will see us on The Sky at Night! www.bbc.co.uk/programmes/m... (plus other features on @vrubinobs.bsky.social and DESI) #scicomm

bbc.co.uk

BBC Four - The Sky at Night, The Expanding Universe

The team explores the expansion of the universe and its role in how the cosmos works.

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Simons Observatory @simonsobservatory.org · 24/07/2025

We're having our collaboration meeting this week! Many of our members went to the University of Manchester, many more are online. Kudos to the local team for an adorable logo (with a pun in it of course) 🐝-modes are the sweetest honey! #AstroSci

A group of about a hundred people arrayed outdoors on a lawn in front of a multi-story brick building detailed with oxidized copper panels. The sky is grey but they are smiling

A roundel with written "Simons Observatory" on top and "Face-2-face Manchester 2025" at the bottom. The roundel shows the Manchester skyline in grey on a black background. A stylized telescope at the bottom left shines a light at a white and orange pixel-art bee.

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Bluefors @bluefors.com · 07/07/2025

At @simonsobservatory.org, Bluefors cooling tech powers ultra-sensitive telescopes mapping the #CosmicMicrowaveBackground —the faint afterglow of the Big Bang. Take a dive into this ambitious #Cosmology project: bluefors.com/stories/big-... #Astrophysics #Astronomy #PhysicsSky #CoolForProgress

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Simons Observatory @simonsobservatory.org · 26/06/2025

Cool results from our cousins at the South Pole Telescope! 🔭 With our Large Aperture Telescope, we hope to reach a similarly exquisite sensitivity as they do on their green patch over a large sky area (that I crudely outlined in blue).

An oval projection of the full night sky, with the galaxy forming a wispy horseshoe figure through it. several trapezoids of color cover different parts of it. The original caption reads:
"FIG. 3. Footprints of the SPT-3G surveys—Main (green filled area), Summer (orange filled area), and Wide (red filled area)—shown alongside the ACT DR6 survey mask (blue solid line). We show Galactic dust as measured by Planck in the background [45] and indicate the most contaminated region with the Planck GAL080 mask as shown in gray shading with a white border. This work is based on observations of the SPT-3G Main field. The combination of the SPT-3G Main, SPT-3G
Summer, and SPT-3G Wide fields will constitute the Ext-10k field, which will probe 25% of the sky with low noise and high resolution."

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Atacama Cosmology Telescope y Simons Observatory en Español @act-simonsobs-es.bsky.social · 13/05/2025

Hoy se cumplen 60 años de la publicación del descubrimiento del Fondo Cósmico de Microondas por Arno Penzias y Robert Wilson! 🥳 Compartimos la columna de nuestro investigador @csifon.bsky.social resumiendo la importancia de este descubrimiento

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Simons Observatory @simonsobservatory.org · 06/05/2025

OK, who was throwing a rave inside the Large Aperture Telescope 🔭? (Image credit: Prof. Suzanne Staggs, Princeton)

A night photo of a large building-sized telescope. The building is in two parts: a big u-shaped structure is mounted on a pivot, and itself ensnares a smaller brick-shaped box that can swivel with a hole in it. Some rocks in the background are visible in yellow, illuminated by an unseen source. Red safety lights at the bottom of the U element and ice blue light from within the telescope's opening complete the scene

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Simons Observatory @simonsobservatory.org · 28/04/2025

We had snow last week at our site! Our telescopes 🔭 like being cold, our teams not so much. Here you are looking inside the sun-shield of one of the SO SATs, the actual lenses and the focal plane sit beneath that shiny cover, cooled to cryogenic temperatures. Image credit: Dr Elle Shaw, UT Austin

A front view of one of the SO Small aperture telescopes from up close. The top half of the image is filled by a conical structure we are looking into: its inside is covered with a white, wallpaper looking structure. There is snow piled up on the bottom lip of the cone. At the end of the cone is an aluminium foil cover.
Beneath and behind the cone you can see a white metal platform that holds the rest of the telescope, including its mount. Various surfaces are covered in snow, black cables meander around the scene.
In the background, a deep blue sky and a shiny screen that provides additional sun and terrain shielding.

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Simons Observatory @simonsobservatory.org · 18/04/2025

"A beginning is the time for taking the most delicate care that the balances are correct." -Frank Herbert, Dune Our Rubin colleagues are starting an exciting commissioning period in Chile, like us with our LAT!

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Simons Observatory @simonsobservatory.org · 10/04/2025

This week, we are trying to assess performance of our Large Aperture Telescope by looking at the planet Mars. For our telescope, it appears as a point, so we can understand our optical response and pointing by observing it. Image credit: Mark Devlin. ☄️🔭

The Simons Observatory LAT with its aperture open, looking at the sky at night. Red safety lights illuminate the bottom of the telescope structure, while a few stars shine in the background.

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Jenna Moore, Ph. D. 🔭✨ @drjmo.bsky.social · 10/04/2025

@evevavagiakis.bsky.social introduces Large™️ @simonsobservatory.org telescope to a standing room only crowd at @astronomyontap.bsky.social Durham!

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Simons Observatory @simonsobservatory.org · 30/03/2025

Fun fact: Three out of the eight schools in the Elite Eight of the Women's March Madness are members of the Simons Observatory: Duke, USC, and UT Austin. 🏀 If you want your team to get good, consider convincing your institution to join us! (Of course, there is a relevant xkcd: xkcd.com/1365/)

xkcd.com

Inflation

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Simons Foundation @simonsfoundation.org · 18/03/2025

The @simonsobservatory.org recently completed the installation of its Large Aperture Telescope, joining its three Small Aperture Telescopes. These telescopes will collect the most precise measurements yet of the universe’s oldest light. www.simonsfoundation.org/2025/03/17/s... #science #astronomy

simonsfoundation.org

Simons Observatory Large Aperture Telescope Achieves First Light Milestone

Simons Observatory Large Aperture Telescope Achieves First Light Milestone on Simons Foundation

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Simons Observatory @simonsobservatory.org · 17/03/2025

If you're curious about the LAT's abilities, here's a thread from a few weeks ago:

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Simons Observatory @simonsobservatory.org · 17/03/2025

We have first light on our Large Aperture Telescope! www.simonsfoundation.org/2025/03/17/s... After installing our mirrors over the last few weeks, we have started looking at the sky. We are still tuning the telescope, but we can already make maps of objects in the sky, like Mars. ☄️🔭🧪

A green dot (Mars) surrounded by a white ring on a purple background. A faint white x pattern is visible

One of the mirrors being lowered by crane inside the white box that constitutes the LAT housing. Behind it is the barren landscape of the Atacama desert

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Atacama Cosmology Telescope y Simons Observatory en Español @act-simonsobs-es.bsky.social · 13/03/2025

¡La nueva página del Observatorio Simons ya está disponible! Por ahora solo en inglés, pronto viene la versión en castellano. ¿Qué les parece? ¡Déjennos sus comentarios! simonsobservatory.org/institutions/

simonsobservatory.org

Institutions |

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Simons Observatory @simonsobservatory.org · 13/03/2025

We have a brand new website! simonsobservatory.org Go check it out for information on what we do, recent publications, and cool images. 🧪🔭

A drone view of the Atacama desert on a clear day with the SO site in the foreground.

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Simons Observatory @simonsobservatory.org · 12/03/2025

Good luck out there SPHEREx! May your non-gaussianity constraints have low uncertainty.

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Atacama Cosmology Telescope y Simons Observatory en Español @act-simonsobs-es.bsky.social · 04/03/2025

Hoy publicamos dos artículos en el repositorio #arXiv. En el primero de ellos (arxiv.org/abs/2503.00636) discutimos los principales objetivos científicos de nuestro LAT (recuerden: Large Aperture Telescope, Telescopio de Gran Apertura), que observará la mitad del cielo

Mapa del cielo mostrando el área que observará el Observatorio Simons en comparación a DES, DESI, Euclid y Rubin.

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