David Thilker
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David Thilker
@dthilker.bsky.social
13 followers 18 following 4 posts
Astronomer / Principal Research Scientist at Johns Hopkins University
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Reposted by David Thilker
stsci.edu
Let’s explore two different views of a spiral galaxy. When it comes to NGC 628, #Hubble and #NASAWebb’s images show a contrast between hot stars in visible light, and cool stars and dust in infrared light: https://bit.ly/42XwnGj 🔭 🧪
September 19, 2025 at 3:07 PM
I’m delighted to share the most recent publication from our PHANGS (Physics at High Angular resolution in Nearby GalaxieS) collaboration, detailing physical properties of ~100,000 star clusters and compact associations in 38 nearby spiral galaxies. 1/4 in 🧵 ui.adsabs.harvard.edu/abs/2025ApJS...
PHANGS-HST Catalogs for ∼100,000 Star Clusters and Compact Associations in 38 Galaxies. II. Physical Properties from Decision-tree-based Spectral Energy Distribution Fitting of NUV-U-B-V-I Photometry ...
This paper is the second in a series presenting the catalogs and properties of the largest sample to date of ∼100,000 star clusters and compact associations, in 38 spiral galaxies observed by the PHAN...
ui.adsabs.harvard.edu
August 19, 2025 at 10:56 PM
Reposted by David Thilker
scottwfleming.bsky.social
The work our talented team does to ensure the public learns about discoveries made with NASA telescopes, and our place in the Universe, risks being lost without at least keeping NASA’s funding flat. The current budget plan removes almost all of it. If this matters to you, make sure your reps know.
July 2, 2025 at 8:28 PM
Reposted by David Thilker
stsci.edu
#NASAWebb was built with the promise of revolutionizing astronomy. With three years now under its belt, has Webb lived up to the hype? We sure think so: bit.ly/3ZVIOR9 🔭 🧪
Webb’s image of NGC 1512 shows a face-on barred spiral galaxy anchored by its central region, which is circular and shows a bright white point at the center with blue and yellow circles around it. Outside the core is a large bar structure filled with a haze of blue stars, forming a rough parallelogram shape and taking up about a quarter of the area. The bar is crossed by orange filaments made of stars, gas, and dust that extend diagonally to the top left and bottom right. Outside this, the thick orange spiral arms form a rough oval, and within them there are smaller oval areas that appear black. The spiral arms are largely orange, ranging from dark to bright orange and extend beyond the edges of the image. There are many larger blue stars and slightly larger pink points of light spread throughout. Two larger foreground stars with at least six diffraction spikes are at top center and bottom center.
July 2, 2025 at 3:04 PM
Reposted by David Thilker
eso.org
Astronomers have created a galactic masterpiece!

Using our VLT, they observed the Sculptor Galaxy in thousands of colours simultaneously 🌈

The more shades of colour there are in an image of a galaxy, the more we can learn about its inner workings.

Read more: www.eso.org/public/news/...
🔭 🧪 ☄️
A spiral galaxy, showing a thousand different colours that indicate the regions of different stars, gas and dust. The centre of the galaxy has more golden and orange light, while the outer edges fade into a deep blue that further fades into the black of the universe. Speckled across the galaxy are portions of bright pink light, along with patches of brown and black.
June 18, 2025 at 12:05 PM
Reposted by David Thilker
stsci.edu
Is it a frisbee? No, but catch this Hubble and #NASAWebb comparison of spiral galaxy NGC 2090. Hubble shows the galaxy’s glowing core, threads of dust, and groups of stars. Webb reveals the spiral arms’ structures and dust particles. 🔭 🧪
June 13, 2025 at 4:19 PM
Reposted by David Thilker
stsci.edu
There’s just something about face-on spiral galaxies!

In 2024, 19 stunning #NASAWebb images of spiral galaxies were released. These observations were part of the PHANGS program to study galaxies’ structures. Hubble’s image is at left, and Webb’s at right: bit.ly/4jq4vQn 🔭 🧪
Two observations of the galaxy NGC 1566 are split diagonally, with Hubble’s observations at top left and Webb’s at bottom right. The galaxy’s core appears centered and the galaxy’s arms rotate counterclockwise. In Hubble’s image, two prominent spiral arms are a mix of dark brown dust lanes and some bright blue and pink star clusters, and the center is pale yellow. In Webb’s image, the spiral arms are shades of orange, with prominent dark gray or black “bubbles,” and there is a blue haze surrounding the core.
May 20, 2025 at 1:24 PM
Reposted by David Thilker
neildegrassetyson.com
If a foreign adversary snuck into our Federal budget and cut science research and education the way we’re cutting it ourselves — strategically undermining America’s long-term health, wealth, and security — we would likely consider it an act of war.
May 19, 2025 at 7:36 PM
Reposted by David Thilker
stsci.edu
No other observatory can match Hubble’s unique abilities.

Credit: NASA Goddard Space Flight Center, ESA, and STScI. 🧪 🔭
May 12, 2025 at 1:25 PM
Reposted by David Thilker
stsci.edu
A key portion of #NASARoman has cleared a thermal vacuum test. Tt was subjected to the hot and cold temperatures it will experience in space: go.nasa.gov/43cwDQL 🔭 🧪
A huge subsystem of the Roman observatory in a thermal vacuum chamber. Seven technicians stand of the side of the observatory, as the bottom of the chamber.
May 8, 2025 at 3:27 PM
Reposted by David Thilker
stsci.edu
A cavernous area fit for a dragon. 🐉

#NASAWebb revealed more than 200 massive, young stars among the pillars of gas and dust in star-forming region NGC 604. This area is more than 2.7 million light-years from Earth in the Triangulum galaxy: bit.ly/4icfWLh 🔭 🧪
At the center is a nebula on the black background of space. The nebula is composed of wispy filaments of light blue clouds. At the center-right of the blue clouds is a large cavernous bubble. The bottom left edge of this cavernous bubble is filled with hues of pink and white gas. There are several other smaller cavernous bubbles at the top of the nebula, including two tiny cavities at the top center of the image. There are hundreds of dim stars that fill the surrounding area of the nebula.
April 11, 2025 at 2:50 PM
Reposted by David Thilker
aas.org
The American Astronomical Society is gravely concerned by the deep cuts to NASA science funding reported to be in the draft President’s Budget Request for Fiscal Year 2026. Read more here: aas.org/press/aas-st... and take action now: aas.org/urge-nasa-su...
April 11, 2025 at 8:04 PM
Reposted by David Thilker
scottwfleming.bsky.social
New Hello Universe project: Interpreting Convolutional Neural Networks - a tutorial of techniques that can be used to visualize the importance of data features in machine learning models. archive.stsci.edu/hello-univer...
New Hello Universe project: Interpreting Convolutional Neural Networks - a tutorial of techniques that can be used to visualize the importance of data features in machine learning models.
June 10, 2024 at 2:02 PM