Today, the 4th observing run (O4) of the gravitational-wave detectors has been running for 110 days.

So far, 37 “significant signal candidates” have been announced.

This means that there is a new possible gravitational-wave signal about every three days. Not all candidates will be real, but neither will all signals be found in this “online” analysis. It remains exciting!

All candidates: https://gracedb.ligo.org/superevents/public/O4/

#Gravitationalwaves #O4IsHere

Scientists Discover A #Climate #TippingPoint Could Be Far Worse Than We Thought : Medium

Tidal forces carry the #Mathematical #Signature of #GravitationalWaves : Tech Review

Have we overestimated the number of #Stars in the #Universe? : Big Think

Check our latest #KnowledgeLinks

https://knowledgezone.co.in/resources/bookmarks

Neue Multi-Messenger-Astronomie-Veröffentlichung von Astronom:innen und @LIGO@astrodon.social-Virgo-KAGRA-Froschenden auf dem arXiv veröffentlicht: „A Joint Fermi-GBM and Swift-BAT Analysis of Gravitational-Wave Candidates from the Third Gravitational-wave Observing Run“

📄 https://arxiv.org/abs/2308.13666 [Veröffentlichung]
📘 https://www.ligo.org/science/Publication-O3GammaRayFollowUp/ [Hintergrund und Erklärungen in der „Science Summary“]

#GammaRayBurst #GravitationalWaves

New multi-messenger astronomy paper by astronomers and @LIGO@astrodon.social-Virgo-KAGRA scientists out on the arXiv: “A Joint Fermi-GBM and Swift-BAT Analysis of Gravitational-Wave Candidates from the Third Gravitational-wave Observing Run”

📄 https://arxiv.org/abs/2308.13666 [paper]
📘 https://www.ligo.org/science/Publication-O3GammaRayFollowUp/ [background and explanations in science summary]

#GammaRayBurst #GravitationalWaves

It's Time for a Gravitational Wave Observatory in the Southern Hemisphere

All current and planned gravitational wave observatories are located in the northern hemisphere, in the US, India, Europe, and Japan. Even the next-generation observatories like Cosmic Explorer 40-km and the Einstein Telescope will be in the north. But a telescope in the southern hemisphere would provide a much larger baseline, allowing the detection of fainter gravitational waves. A new paper makes the case for building an observatory south of the equator.

#gravitationalwaves

https://www.universetoday.com/162961/its-time-for-a-gravitational-wave-observatory-in-the-southern-hemisphere/

The 4th observing run (O4) of @LIGO, Virgo, KAGRA and GEO600 has been ongoing for 14 weeks.

So far, 35 significant candidate signal (https://gracedb.ligo.org/superevents/public/O4/) have been found. Not all of them have to be real, but there will also be faint undetected signals.

There is a new signal candidate every 2.8 days.

For comparison, there were also 35 signals in the 2nd half of the previous observing run (O3b), but in 21 weeks – a new signal every 4.2 days.

#GravitationalWaves #O4IsHere

Wednesday starts with an exciting gravitational wave candidate from @LIGO. If real, it is likely from the rather rare merger of a neutron star with a black hole. The distance is about 700 million light-years. The sky position is fairly well constrained by observation with both LIGO detectors.

ℹ️ https://gracedb.ligo.org/superevents/S230830b/

#GravitationalWaves #S230830b

It's Time for a Gravitational Wave Observatory in the Southern Hemisphere

All current and planned gravitational wave observatories are located in the northern hemisphere, in the US, India, Europe, and Japan. Even the next-generation observatories like Cosmic Explorer 40-km and the Einstein Telescope will be in the north. But a telescope in the southern hemisphere would provide a much larger baseline, allowing the detection of fainter gravitational waves. A new paper makes the case for building an observatory south of the equator.

#gravitationalwaves

http://arxiv.org/abs/2308.13103

"Earlier this year, after 15 years of searching, scientists finally heard the background hum of low-frequency #gravitationalwaves that fill our #universe," writes Space.com
Scientists' recent detection of low-frequency gravitational waves may shed light on what's causing a constant rumble of ripples in the very fabric of #space and time. https://www.space.com/supermassive-black-holes-may-solve-mystery-universe-gravitationa-wave-hum

On Saturday, September 30, 2023, the @mpi_grav and the Institute for Gravitational Physics of @UniHannover invite you to visit the German-British gravitational-wave detector GEO600 near Sarstedt.

➡️ https://www.geo600.org/openday23

#GravitationalWaves #SciComm

Read up on recent news and upcoming topics in gravitational-wave astronomy, featuring Pulsar Timing Arrays, @LIGO, Virgo, and LISA in this Scientific American article by @astrojonny:

➡️ https://www.scientificamerican.com/article/a-background-hum-pervades-the-universe-scientists-are-racing-to-find-its-source/

#GravitationalWaves #Astronomy #BlackHoles #LISAMission #PulsarTimingArrays

New status from the current 4th joint gravitational-wave observing run (O4):

⌛ Since the start of O4: 89 days

🔢 Number of significant signal candidates: 32

➡️ There is a new signal candidate every 2.8 days.

At the end of the planned O4 runtime (20 months), there could be >200 candidates.

Not all candidates will be confirmed as signals after further analyses. But these should detect more signals not found so far.

#GravitationalWaves #O4

#GravitationalWaves Ripping Apart Whole #Planets?
https://www.newscientist.com/article/2387387-could-a-gravitational-wave-rip-apart-an-entire-planet/
#gravity #cosmos #planet #universe

Happy Birthday, GW170817! Six years ago today, @LIGO and Virgo observed gravitational waves from merging neutron stars for the first time, and many other telescopes observed the electromagnetic radiation produced by the event.

Our press release about the event: https://www.aei.mpg.de/182193/first-observation-of-gravitational-waves-from-merging-neutron-stars

Numerical simulation: https://www.youtube.com/watch?v=V6cm-0bwJ98

#GW170817 #GravitationalWaves #BinaryNeutronStar

Want to stay up to date with the latest gravitational-wave signal candidates from @LIGO, Virgo, and KAGRA? Check out Chirp!

➡️ https://chirp.research.exeter.ac.uk

#GravitationalWaves #Astronomy #Chirp

Scientists have detected a background hum of low-frequency gravitational waves that pervades the universe. These waves are different from the ones produced by colliding black holes or neutron stars, which have been observed by LIGO and Virgo. The origin of this hum is unknown, but it could reveal new physics and exotic phenomena, such as supermassive black hole mergers or cosmic strings. #GravitationalWaves #Astronomy #Mystery https://www.scientificamerican.com/article/a-background-hum-pervades-the-universe-scientists-are-racing-to-find-its-source/?utm_source=flipboard&utm_content=HariTulsidas%2Fmagazine%2FMind+and+Matter

📢 New selected research highlight: Next-level squeezed light for Advanced Virgo – researchers at @mpi_grav and Leibniz University Hannover help set up and characterize the frequency-dependent squeezed-light source

➡️ https://www.aei.mpg.de/1063452/next-level-squeezed-light-for-advanced-virgo

📰 https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.041403 (Open Access)

#GravitationalWaves #SqueezedLight #QuantumOptics

// #Astronomers are now seeking to pinpoint the origins of a new form of #gravitationalwaves : https://www.scientificamerican.com/article/a-background-hum-pervades-the-universe-scientists-are-racing-to-find-its-source/

: #repost #scientificamerican #timeline

Attending my first in person #JSM this week. It'll be speaking about searches for continuous gravitational waves Tuesday morning in the topic contributed session on "Pulling Signal out of Noise for Data-Driven Discoveries in Astronomy". #JSM2023 #GravitationalWaves #LIGO #Virgo #KAGRA

#JuanMaldacena - What is #Spacetime?

https://www.youtube.com/watch?v=yHh3RmYCXWA&ab_channel=CloserToTruth

#Philosophy #PhilosophyOfScience #Science #Physics #PhilosophyOfCosmology #Cosmology #Expansion #Astrphysics #Relativity #Mass #Energy #GR #GeneralRelativity #Space #Time #GravitationalWaves #StringTheory #CloserToTruth #RobertKuhn