8/9
This work has been extended and updated in 2025:
- “The Milky Way as Seen by Classical Cepheids I: Distances Based on Mid-infrared Photometry”-> arxiv.org/abs/2406.09113
- “The Milky Way as Seen by Classical Cepheids II: Spiral Structure”-> arxiv.org/abs/2406.09127
This work has been extended and updated in 2025:
- “The Milky Way as Seen by Classical Cepheids I: Distances Based on Mid-infrared Photometry”-> arxiv.org/abs/2406.09113
- “The Milky Way as Seen by Classical Cepheids II: Spiral Structure”-> arxiv.org/abs/2406.09127
The Milky Way as Seen by Classical Cepheids I: Distances Based on Mid-infrared Photometry
Classical Cepheids are the archetype of the standard candle, thanks to the period-luminosity relation which allows to measure their intrinsic brightness. They are also relatively young and bright, pot...
arxiv.org
August 11, 2026 at 5:39 PM
8/9
This work has been extended and updated in 2025:
- “The Milky Way as Seen by Classical Cepheids I: Distances Based on Mid-infrared Photometry”-> arxiv.org/abs/2406.09113
- “The Milky Way as Seen by Classical Cepheids II: Spiral Structure”-> arxiv.org/abs/2406.09127
This work has been extended and updated in 2025:
- “The Milky Way as Seen by Classical Cepheids I: Distances Based on Mid-infrared Photometry”-> arxiv.org/abs/2406.09113
- “The Milky Way as Seen by Classical Cepheids II: Spiral Structure”-> arxiv.org/abs/2406.09127
1/9
In 2019, a Warsaw research team presented the first 3D map of the Milky Way in the journal Science.
The map is based on direct distances to thousands of Cepheids.
A pioneering achievement, still widely cited. 🔭🧪⚛️
#galactic #astronomy #universe
In 2019, a Warsaw research team presented the first 3D map of the Milky Way in the journal Science.
The map is based on direct distances to thousands of Cepheids.
A pioneering achievement, still widely cited. 🔭🧪⚛️
#galactic #astronomy #universe
August 11, 2026 at 5:39 PM
1/9
In 2019, a Warsaw research team presented the first 3D map of the Milky Way in the journal Science.
The map is based on direct distances to thousands of Cepheids.
A pioneering achievement, still widely cited. 🔭🧪⚛️
#galactic #astronomy #universe
In 2019, a Warsaw research team presented the first 3D map of the Milky Way in the journal Science.
The map is based on direct distances to thousands of Cepheids.
A pioneering achievement, still widely cited. 🔭🧪⚛️
#galactic #astronomy #universe
RS Puppis.
At a distance of 6,000 light-years, the Cepheid variable star was observed by Hubble and is one of the biggest and brightest known Cepheids in the Milky Way galaxy.
Processed by @thocarp.bsky.social
www.flickr.com/photos/19746...
🔭 🧪
At a distance of 6,000 light-years, the Cepheid variable star was observed by Hubble and is one of the biggest and brightest known Cepheids in the Milky Way galaxy.
Processed by @thocarp.bsky.social
www.flickr.com/photos/19746...
🔭 🧪
January 17, 2025 at 9:29 PM
RS Puppis.
At a distance of 6,000 light-years, the Cepheid variable star was observed by Hubble and is one of the biggest and brightest known Cepheids in the Milky Way galaxy.
Processed by @thocarp.bsky.social
www.flickr.com/photos/19746...
🔭 🧪
At a distance of 6,000 light-years, the Cepheid variable star was observed by Hubble and is one of the biggest and brightest known Cepheids in the Milky Way galaxy.
Processed by @thocarp.bsky.social
www.flickr.com/photos/19746...
🔭 🧪
Discrimination. Edwin Hubble was in charge of the Harvard Observatory. He determined how big the universe was using cepheid variable stars. Except it was assistant Henrietta Leavitt who discovered cepheids. As a woman she wasn't allowed to get a PhD or use the telescope or we might remember her.
February 7, 2025 at 9:22 PM
Discrimination. Edwin Hubble was in charge of the Harvard Observatory. He determined how big the universe was using cepheid variable stars. Except it was assistant Henrietta Leavitt who discovered cepheids. As a woman she wasn't allowed to get a PhD or use the telescope or we might remember her.
Henrietta Swan Leavitt’s period-luminosity relationship for Cepheids is one of the first rungs on the “cosmic distance ladder,” the collection of methods used by astronomers to measure extragalactic distances. (14/n)
January 1, 2025 at 5:49 PM
Henrietta Swan Leavitt’s period-luminosity relationship for Cepheids is one of the first rungs on the “cosmic distance ladder,” the collection of methods used by astronomers to measure extragalactic distances. (14/n)
Running a bit late on solstice cheers, but this #Hubble image alone is pure gold: breathtaking face-on view of spiral galaxy NGC 1309. 🔭
Bonus — it has helped us nail down the cosmic distance ladder using Cepheids and Type Ia supernovae.
Definitely worth your time — go read the article! 🧪📖
Bonus — it has helped us nail down the cosmic distance ladder using Cepheids and Type Ia supernovae.
Definitely worth your time — go read the article! 🧪📖
I gripe a little bit about the ambiguity of the word "day" — astronomically speaking, of course — and also present you with a *gorgeous* Hubble shot of a face-spiral galaxy that turns out to be part of the puzzle that tells us how the universe expands.
badastronomy.beehiiv.com/p/happy-sols...
🔭 🧪
badastronomy.beehiiv.com/p/happy-sols...
🔭 🧪
Happy solstice, and a gorgeous galaxy with which to measure the Universe
The longest night is now behind us, and a Hubble image of a galaxy used as a ruler
badastronomy.beehiiv.com
December 23, 2025 at 9:54 AM
Running a bit late on solstice cheers, but this #Hubble image alone is pure gold: breathtaking face-on view of spiral galaxy NGC 1309. 🔭
Bonus — it has helped us nail down the cosmic distance ladder using Cepheids and Type Ia supernovae.
Definitely worth your time — go read the article! 🧪📖
Bonus — it has helped us nail down the cosmic distance ladder using Cepheids and Type Ia supernovae.
Definitely worth your time — go read the article! 🧪📖
Program 2875 - Scrutinizing the Dirtiest Cepheids, a Test of the Hubble Tension: www.stsci.edu/jwst/phase2-...
Data: NGC-3370, released 2025-05-24
NASA, STSci/ #JWST, NIRCam /RGB: 277, 150, 090
Data: NGC-3370, released 2025-05-24
NASA, STSci/ #JWST, NIRCam /RGB: 277, 150, 090
May 25, 2025 at 6:13 PM
Program 2875 - Scrutinizing the Dirtiest Cepheids, a Test of the Hubble Tension: www.stsci.edu/jwst/phase2-...
Data: NGC-3370, released 2025-05-24
NASA, STSci/ #JWST, NIRCam /RGB: 277, 150, 090
Data: NGC-3370, released 2025-05-24
NASA, STSci/ #JWST, NIRCam /RGB: 277, 150, 090
or whether it was merely further away. Swan Leavitt's discovery lets astronomers use Cepheids as "standard candles". They allow astronomers to determine distances to celestial objects and form the foundation of the Extragalactic Distance Scale.
minouette.etsy.com/listing/4518...
minouette.etsy.com/listing/4518...
minouette.etsy.com
July 4, 2024 at 12:20 PM
or whether it was merely further away. Swan Leavitt's discovery lets astronomers use Cepheids as "standard candles". They allow astronomers to determine distances to celestial objects and form the foundation of the Extragalactic Distance Scale.
minouette.etsy.com/listing/4518...
minouette.etsy.com/listing/4518...
Needless to say, The Dirtiest Cepheids are my Big Star/Mudhoney mashup band.
May 24, 2025 at 3:51 PM
Needless to say, The Dirtiest Cepheids are my Big Star/Mudhoney mashup band.
🔭 JWST Program 2875 - Scrutinizing the Dirtiest Cepheids, a Test of the Hubble Tension: www.stsci.edu/jwst-program...
target: NGC-2525, released: 2025-11-17
NASA, ESA, CSA, STSci/ #JWST NIRCam 277, 150
target: NGC-2525, released: 2025-11-17
NASA, ESA, CSA, STSci/ #JWST NIRCam 277, 150
November 22, 2025 at 10:24 PM
🔭 JWST Program 2875 - Scrutinizing the Dirtiest Cepheids, a Test of the Hubble Tension: www.stsci.edu/jwst-program...
target: NGC-2525, released: 2025-11-17
NASA, ESA, CSA, STSci/ #JWST NIRCam 277, 150
target: NGC-2525, released: 2025-11-17
NASA, ESA, CSA, STSci/ #JWST NIRCam 277, 150
stones havens of southern weather.
Of a woman who watches Cepheids quaver
among lightbursting mangroves.
Of a woman who watches Cepheids quaver
among lightbursting mangroves.
January 8, 2026 at 2:12 AM
stones havens of southern weather.
Of a woman who watches Cepheids quaver
among lightbursting mangroves.
Of a woman who watches Cepheids quaver
among lightbursting mangroves.
James #Webb Space Telescope #JWST
Scrutinizing the Dirtiest Cepheids, a Test of the Hubble Tension
TARG: #NGC2525
2024-11-16
PI: Riess, Adam
NIRCAM 277 150 090
yuval-harpaz.github.io/astro/jwst_l...
NASA/ESA/CSA/STScI/j. Roger
Scrutinizing the Dirtiest Cepheids, a Test of the Hubble Tension
TARG: #NGC2525
2024-11-16
PI: Riess, Adam
NIRCAM 277 150 090
yuval-harpaz.github.io/astro/jwst_l...
NASA/ESA/CSA/STScI/j. Roger
November 20, 2025 at 1:35 PM
James #Webb Space Telescope #JWST
Scrutinizing the Dirtiest Cepheids, a Test of the Hubble Tension
TARG: #NGC2525
2024-11-16
PI: Riess, Adam
NIRCAM 277 150 090
yuval-harpaz.github.io/astro/jwst_l...
NASA/ESA/CSA/STScI/j. Roger
Scrutinizing the Dirtiest Cepheids, a Test of the Hubble Tension
TARG: #NGC2525
2024-11-16
PI: Riess, Adam
NIRCAM 277 150 090
yuval-harpaz.github.io/astro/jwst_l...
NASA/ESA/CSA/STScI/j. Roger
HST key project observation of M81 Cepheids
Image date: 9 June 1993, 06:00
Credit: NASA/ESA, STScI
Source: ESA/Hubble
Image date: 9 June 1993, 06:00
Credit: NASA/ESA, STScI
Source: ESA/Hubble
September 20, 2026 at 9:55 AM
HST key project observation of M81 Cepheids
Image date: 9 June 1993, 06:00
Credit: NASA/ESA, STScI
Source: ESA/Hubble
Image date: 9 June 1993, 06:00
Credit: NASA/ESA, STScI
Source: ESA/Hubble
was less luminous, or whether it was merely further away. Swan Leavitt’s discovery lets astronomers use Cepheids as “standard candles”. They allow astronomers to determine distances to celestial objects and form the foundation of the Extragalactic Distance Scale.
#linocut #printmaking #astronomy
#linocut #printmaking #astronomy
July 4, 2026 at 12:27 PM
was less luminous, or whether it was merely further away. Swan Leavitt’s discovery lets astronomers use Cepheids as “standard candles”. They allow astronomers to determine distances to celestial objects and form the foundation of the Extragalactic Distance Scale.
#linocut #printmaking #astronomy
#linocut #printmaking #astronomy
2/9
Cepheids are relatively young pulsating supergiant stars whose brightness varies according to a very regular pattern with a well-defined period that can range from a few hours to several tens of days.
They are therefore perfect cosmic tracers.
Cepheids are relatively young pulsating supergiant stars whose brightness varies according to a very regular pattern with a well-defined period that can range from a few hours to several tens of days.
They are therefore perfect cosmic tracers.
August 11, 2026 at 5:39 PM
2/9
Cepheids are relatively young pulsating supergiant stars whose brightness varies according to a very regular pattern with a well-defined period that can range from a few hours to several tens of days.
They are therefore perfect cosmic tracers.
Cepheids are relatively young pulsating supergiant stars whose brightness varies according to a very regular pattern with a well-defined period that can range from a few hours to several tens of days.
They are therefore perfect cosmic tracers.
Wilma Kiviaho, et al.: Interstellar extinction of classical Cepheids from neighboring stars I. Methodology and application to 16 Galactic Cepheids https://arxiv.org/abs/2609.28406 https://arxiv.org/pdf/2609.28406 https://arxiv.org/html/2609.28406
September 24, 2026 at 6:51 AM
Wilma Kiviaho, et al.: Interstellar extinction of classical Cepheids from neighboring stars I. Methodology and application to 16 Galactic Cepheids https://arxiv.org/abs/2609.28406 https://arxiv.org/pdf/2609.28406 https://arxiv.org/html/2609.28406
A few months ago, Hubble observed the NGC-3370 galaxy, and today the data was released. So here's my go at it! 🔭
It is located some ~80 million light years away from us, and it was observed to study Cepheids to improve our cosmological model.
HD: flic.kr/p/2r5F4Wf
It is located some ~80 million light years away from us, and it was observed to study Cepheids to improve our cosmological model.
HD: flic.kr/p/2r5F4Wf
May 19, 2025 at 3:28 PM
A few months ago, Hubble observed the NGC-3370 galaxy, and today the data was released. So here's my go at it! 🔭
It is located some ~80 million light years away from us, and it was observed to study Cepheids to improve our cosmological model.
HD: flic.kr/p/2r5F4Wf
It is located some ~80 million light years away from us, and it was observed to study Cepheids to improve our cosmological model.
HD: flic.kr/p/2r5F4Wf
7/9
...spiral arms.
A simple simulation of star formation episodes in the arms, taking into account differential rotation (stars and arms rotate at different speeds), reproduces well the overdensities observed today.
It confirms that many Cepheids formed in the arms and then moved away.
...spiral arms.
A simple simulation of star formation episodes in the arms, taking into account differential rotation (stars and arms rotate at different speeds), reproduces well the overdensities observed today.
It confirms that many Cepheids formed in the arms and then moved away.
August 11, 2026 at 5:39 PM
7/9
...spiral arms.
A simple simulation of star formation episodes in the arms, taking into account differential rotation (stars and arms rotate at different speeds), reproduces well the overdensities observed today.
It confirms that many Cepheids formed in the arms and then moved away.
...spiral arms.
A simple simulation of star formation episodes in the arms, taking into account differential rotation (stars and arms rotate at different speeds), reproduces well the overdensities observed today.
It confirms that many Cepheids formed in the arms and then moved away.
3/9
The team measured 2,431 classical Cepheids, most of them discovered by the OGLE survey.
Infrared period-luminosity relations gave distances accurate to better than 5%.
This is the first map that reaches the outer edge of the disk using individual stars.
The team measured 2,431 classical Cepheids, most of them discovered by the OGLE survey.
Infrared period-luminosity relations gave distances accurate to better than 5%.
This is the first map that reaches the outer edge of the disk using individual stars.
August 11, 2026 at 5:39 PM
3/9
The team measured 2,431 classical Cepheids, most of them discovered by the OGLE survey.
Infrared period-luminosity relations gave distances accurate to better than 5%.
This is the first map that reaches the outer edge of the disk using individual stars.
The team measured 2,431 classical Cepheids, most of them discovered by the OGLE survey.
Infrared period-luminosity relations gave distances accurate to better than 5%.
This is the first map that reaches the outer edge of the disk using individual stars.
Program 2875 - Scrutinizing the Dirtiest Cepheids, a Test of the Hubble Tension: www.stsci.edu/jwst/phase2-...
Data: NGC-3447, released 2025-05-23
NASA, STSci/ #JWST, NIRCam / RGB: 356, 277, 150
Data: NGC-3447, released 2025-05-23
NASA, STSci/ #JWST, NIRCam / RGB: 356, 277, 150
May 24, 2025 at 7:27 PM
Program 2875 - Scrutinizing the Dirtiest Cepheids, a Test of the Hubble Tension: www.stsci.edu/jwst/phase2-...
Data: NGC-3447, released 2025-05-23
NASA, STSci/ #JWST, NIRCam / RGB: 356, 277, 150
Data: NGC-3447, released 2025-05-23
NASA, STSci/ #JWST, NIRCam / RGB: 356, 277, 150