Pavel Kroupa: press releases (post-2005)

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44) Oct. 2022:
Are Newton and Einstein in error after all? (in English, ESA/Gaia image of the week)
Astronomie: Beobachtung gibt Forschenden Raetsel auf (in German, Press Release, University of Bonn)
Astronomy: Observation puzzles researchers (in English, Press Release, University of Bonn)
Jak otevrene hvezdokupy prichazy o hvezdy (in Czech, Press Release, Charles University in Prague)

Based on Asymmetrical tidal tails of open star clusters: stars crossing their cluster's prah challenge Newtonian gravitation : Pavel Kroupa, Tereza Jerabkova, Ingo Thies, Jan Pflamm-Altenburg et al. (2022, MNRAS, published)

43) Aug. 2022:
Keine Spur von Halos aus Dunkler Materie (in German, Press Release, University of Bonn)
Study finds no dark matter halos in the dwarf galaxies of one of Earth's nearest clusters (in English, Press Release, University of St. Andrews)

Based on The distribution and morphologies of Fornax Cluster dwarf galaxies suggest they lack dark matter : Elena Asencio, Indranil Banik, Steffen Mieske, Aku Venhola, Pavel Kroupa, Hongsheng Zhao (2022, MNRAS 515, 2981)

42) Feb. 2022:
Too many disk galaxies than theory allows. A study by the University of Bonn: Observations fit poorly with the Standard Model of Cosmology (in English, Press Release, University of Bonn)

Based on The High Fraction of Thin Disk Galaxies Continues to Challenge LCDM Cosmology : Moritz Haslbauer, Indranil Banik, Pavel Kroupa, Nils Wittenburg, Behnam Javanmardi (2022, The Astrophysical Journal 925, 183)

41) Sept. 2020:
The enduring mystery of how galaxies grow up (in English, Oxford University Press blog)

Based on Constraints on the star formation histories of galaxies in the Local Cosmological Volume : Pavel Kroupa, Moritz Haslbauer, Indranil Banik, Srikanth T. Nagesh, Jan Pflamm-Altenburg (2020, The Monthly Notices of the Royal Astronomical Society, in press)

40) Feb. 2020:
Galaxy formation simulated without dark matter (in English, University of Bonn)

Galaxien-Entstehung ohne Dunkle Materie simuliert (in German, University of Bonn)

Prvni simulace vzniku galaxii bez temne hmoty (in Czech, Faculty of Mathematics and Physics, Charles University)

Based on The formation of exponential disk galaxies in MOND : Nils Wittenburg, Pavel Kroupa, Benoit Famaey (2020, The Astrophysical Journal, in press)

39) May 2019:
Simulated galaxies without dark matter (in English, Faculty of Mathematics and Physics, Charles University)

Simulation zeigt: Es gibt Galaxien ohne Dunkle Materie (in German, University of Bonn)

Simulace vrha svetlo na galaxie bez temne hmoty (in Czech, Faculty of Mathematics and Physics, Charles University)

Based on Galaxies lacking dark matter in the Illustris simulation : Moritz Haslbauer, Joerg Dabringhausen, Pavel Kroupa, Behnam Javanmardi, Indranil Banik (2019, Astronomy and Astrophysics, in press)

Highlighted in Nature Astronomy Simulating the absence of dark matter : by Marios Karouzos (Nature Astronomy 3, 477, 2019)

38) September 2018: Gravity theory saved from death (in English on Phys.Org.)

Widerlegt eine Zwerg-Galaxie die MOND-Theorie? (in German, Informationsdienst Wissenschaft)

Velká tvrzení o trpasličí galaxii (in Czech, Faculty of Mathematics and Physics, Charles University)

Based on Does the galaxy NGC1052-DF2 falsify Milgromian dynamics? : Pavel Kroupa, Hosein Haghi, Behnam Javanmardi, Akram Hasani Zonoozi, Oliver Mueller, Indranil Banik, Xufen Wu, Hongsheng Zhao \& Joerg Dabringhausen (2018, Nature Volume 561, pagesE4–E5)

37) November 2015: Astronomers discover low surface brightness galaxies with amateur telescopes (in English)

by Tomasz Nowakowski on Phys.Org

Based on DGSAT: Dwarf Galaxy Survey with Amateur Telescopes I. Discovery of low surface brightness systems around nearby spiral galaxies : B. Javanmardi, D. Martinez-Delgado, P. Kroupa, C. Henkel, K. Crawford, K. Teuwen, R. J. Gabany, M. Hanson, F. Neyer, 2015, A&A, submitted

36) April 2015: Die Vermessung der Milchstrasse (in German)

Based on Globular Cluster Streams as Galactic High-Precision Scales - The Poster Child Palomar 5 : Kuepper, Andreas H. W.; Balbinot, Eduardo; Bonaca, Ana; Johnston, Kathryn V.; Hogg, David W.; Kroupa, Pavel; Santiago, Basilio X., 2015, ApJ, in press

35) April 2015: Forscher der Uni Bonn entdecken kosmischen Booster (in German)

Based on Dependency of dynamical ejections of O stars on the masses of very young star clusters : Seungkyung Oh, Pavel Kroupa, Jan Pflamm-Altenburg, 2015, ApJ, in press

34) February 2015: SWR1 Leute TV, 05.02.2015 (in German)

Audio only

33) January 2015: Krieg um Sterne, Sueddeutsche , 19.01.2015 (in German)

32) June 2014: Map of universe questioned: Dwarf galaxies don't fit standard model

List of other related press releases on this issue: Co-orbiting satellite galaxy structures are still in conflict with the distribution of primordial dwarf galaxies

Based on Co-orbiting satellite galaxy structures are still in conflict with the distribution of primordial dwarf galaxies : Pawlowski, Marcel S.; Famaey, Benoit; Jerjen, Helmut; Merritt, David; Kroupa, Pavel; Dabringhausen, Joerg; Lueghausen, Fabian; Forbes, Duncan A.; Hensler, Gerhard; Hammer, François; Puech, Mathieu; Fouquet, Sylvain; Flores, Hector; Yang, Yanbin 2014, MNRAS, in press

31) July 2013: Beinahe-Crash im Universum: Berechnungen legen nahe, dass sich Milchstrasse und Andromeda-Galaxie vor zehn Milliarden Jahre streiften

RAS press release: Did Andromeda crash into the Milky Way 10 billion years ago?

Based on Local Group timing in Milgromian dynamics. A past Milky Way-Andromeda encounter at z>0.8 : HongSheng Zhao, Benoit Famaey, Fabian Lueghausen, Pavel Kroupa 2013, A&A, in press

30) January 2013: Wie am Gummiband: Forscher der Universit舩 Bonn berechnen die Geburt von Sternhaufen

Based on Did the infant R136 and NGC 3603 clusters undergo residual gas expulsion? : Sambaran Banerjee & Pavel Kroupa 2013, ApJ, in press

29) September 2012: Wilder Tanz im Schwert des Orion: Forscher unter Beteiligung der Uni Bonn vermuten ein massives Schwarzes Loch im Zentrum des Sternbilds

English: International study suggests a massive black hole exists in the Sword of Orion (University of Queensland PR)

Tschechish/Czech (Karl's Universitaet Praha/Charles University in Prague): Skryva Orionuv mec cernou diru 200krat tezsi nez Slunce?

Based on Catch me if you can: is there a runaway-mass black hole in the Orion Nebula Cluster? : Ladislav Subr, Pavel Kroupa, Holger Baumgardt, 2012, ApJ, 757, 37

28) August 2012: Geheimnis der raetselhaften "Monstersterne" geknackt

English: Astronomers crack mystery of the "monster stars" (RAS PR)

Based on The emergence of super-canonical stars in R136-type star-burst clusters : Sambaran Banerjee, Pavel Kroupa, Seungkyung Oh, 2012, MNRAS, in press

27) May 2012: Forscher untersuchen, wie die Natur bei der Bildung von Sternen hilft

English: How nature shapes the birth of stars (RAS PR)

Based on Evidence for top-heavy stellar initial mass functions with increasing density and decreasing metallicity : Michael Marks, Pavel Kroupa, Joerg Dabringhausen, Marcel Pawlowski, 2012, MNRAS, 422, 2246-2254

26) May 2012: Scheidung im Universum

Based on Inverse dynamical population synthesis: Constraining the initial conditions of young stellar clusters by studying their binary populations : Michael Marks, Pavel Kroupa, 2012, MNRAS, in press

Video: Das dynamische Aufloesung von Doppelsternen

25) April 2012: Keine Dunkle Materie in der Milchstrasse?

English: Do the Milky Way companions spell trouble for dark matter? (RAS PR)

Based on The VPOS: a vast polar structure of satellite galaxies, globular clusters and streams around the Milky Way : Marcel Pawlowski, Jan Pflamm-Altenburg, Pavel Kroupa 2012, MNRAS, in press

Video: The Vast Polar Structure (VPOS) around the Milky Way

24) October 2011: Eine neue Art Himmelskoerper: Dunkle Sternhaufen

English: Physicists discover a new kind of celestial bodies: Dark Star Clusters

Based on A New Type of Compact Stellar Population: Dark Star Clusters : Sambaran Banerjee, Pavel Kroupa 2011, ApJ, 741L, 12

Video: The formation of a dark star cluster and the radiation of gravitational waves from it.

23) August 2011: How single stars lost their companions (RAS PR)

Based on Dynamical population synthesis: Constructing the stellar single and binary contents of galactic field populations : Michael Marks, Pavel Kroupa 2011, MNRAS, in press

22) August 2011: Die Geburt von Planetensystemen: Stテシrmischer Tanz der jungen Sterne

English (Royal Astronomical Society: Interstellar crashes could throw out habitable planets

Based on A natural formation scenario for misaligned and short-period eccentric extrasolar planets : Ingo Thies, Pavel Kroupa, Simon P. Goodwin, Dimitris Stamatellos, Anthony P. Whitworth 2011, MNRAS, in press

21) July 2011: Kosmische Geisterfahrer: Astronomen der Universitテ、t Bonn entdecken Ueberreste eines gigantischen Crashs in unserer Milchstrasse

Based on Making Counter-Orbiting Tidal Debris: The Origin of the Milky Way Disc of Satellites : Marcel S. Pawlowski, Pavel Kroupa, Klaas S. de Boer 2011, A & A, in press

20) January 2011: In English: What is a galaxy? Cast your vote here...

See the MIT jorunal Technology Review edition of January 21st, 2011: Astronomers Crowdsource the Definition of a Galaxy

Science and New Scientist report on this question.

See the SciLogs article in the series The Dark Matter Crisis of January 19th, 2011: Question B1: What is a galaxy?

Based on What is a Galaxy? Cast your vote here... : Forbes, D. & Kroupa, P., PASA, in press

19) November and December 2010: MOND - Modifizierte Newtonsche Dynamik: Eine neue Theorie, die Luecken schliessen soll (TV programme on 3Sat)

English: Dark Matter: A debate (Uni-Bonn-TV podcast will become available here)

See also the major article in the South China Morning Post edition of December 28th, 2010: Delving deep for the dark arts of physics: Lab hunts for particles that may not be there

Based on Local-Group tests of dark-matter concordance cosmology . Towards a new paradigm for structure formation : Kroupa, P.; Famaey, B.; de Boer, K. S.; Dabringhausen, J.; Pawlowski, M. S.; Boily, C. M.; Jerjen, H.; Forbes, D.; Hensler, G.; Metz, M. 2010, A and A, 523A, 32

18) November 2010: Das Raetsel um die fehlenden Sterne im All scheint geloest

English: The enigma of the missing stars in space may be solved

Based on Top-heavy integrated galactic stellar initial mass functions (IGIMFs) in starbursts : Carsten Weidner, Pavel Kroupa, Jan Pflamm-Altenburg 2010, MNRAS, in press

17) November 2010: Bonner Astronomen haben eine neue Methode entwickelt, um die Sternentstehung in Galaxien nachzuvollziehen

Based on The star formation history of the Large Magellanic Cloud as seen by star clusters and stars : Thomas Mascberger, Pavel Kroupa 2010, MNRAS, in press

16) June 2010: Scientists get a look at the birth of the Milky Way (RAS press release).


Detaillierter Blick in die Geburtsstunde der Milchstrasse (Univ. Bonn press release in German).

Based on Initial conditions for globular clusters and assembly of the old globular cluster population of the Milky Way: Michael Marks, Pavel Kroupa, 2010, MNRAS, in press

15) June 2010: Local-Group-of-galaxies study raises severe doubts as to the existence of dark matter (in German).

Based on Local-Group tests of dark-matter Concordance Cosmology: Towards a new paradigm for structure formation : Pavel Kroupa, Benoit Famaey, Klaas S. de Boer, et al., 2010, Astronomy and Aastrophysics, in press

Note the completely independent Nature Review by James Peebles and Adam Nusser which comes to rather similar conclusions: , 2010, Nature, 465, 565

Can the inclusion of baryonic physics significantly affect the conclusions (that the dark-matter concordance cosmological model appears to be invalidated and we therefore need to study effective non-Newtonian gravity)?

The recent study by Knebe et al. (2010, MNRAS) suggests this not to be the case. They write:

"The most remarkable outcome of this study though remains that the inclusion of gas physics has no affect on the (DM) shapes (and hence radial alignment) of subhaloes in cosmological simulations of structure formation."

So it seems that baryonic physics would not really have an important effect on the conclusions, but further research is clearly useful to further sharpen our understanding.

See also point 9 below. See for further details on the current state of cosmology.

14) June 2010: It's hit-and-run on a cosmic scale. Close encounters between swerving young stars might help spawn the brown dwarfs riddling the Milky Way (New Scientist)

Based on Tidally induced brown dwarf and planet formation in circumstellar discs : Ingo Thies, Pavel Kroupa, Simon Goodwin, Dimitrios Stamatellos, Anthony P. Whitworth, 2010, Astrophysical Journal, in press

13) June 2010: Shockwave reveals star's birthplace: Astronomers spy the trail carved through interstellar gas by a massive runaway in the Large Magellanic Cloud (naturenews).

Based on Massive runaway stars in the Large Magellanic Cloud: Vasilii V. Gvaramadze, Pavel Kroupa, Jan Pflamm-Altenburg, 2010, Astronomy and Astrophysics, in press

12) Dec. 2009: Mit Spielkonsolen auf Einsteins Spuren: Bonner Astronomen zeigen, welche dunklen Maechte als Quellen fuer Gravitationswellen in Frage kommen

Based on Stellar-mass black holes in star clusters: implications for gravitational wave radiation : Sambaran Banerjee, Holger Baumgardt, Pavel Kroupa MNAS, 402, 371-380

11) Dec. 2009: Sternentstehung findet im Verborgenen statt: Vorhersage von Bonner Astronomen durch amerikanische Studie bestaetigt

Based on Comparison of Hテ篠ア and UV Star Formation Rates in the Local Volume: Systematic Discrepancies for Dwarf Galaxies : Janice Lee et al. 2009, ApJ 706, 599

Based on Diverging UV and Hテ篠ア fluxes of star-forming galaxies predicted by the IGIMF theory : Jan Pflamm-Altenburg; Carsten Weidner; Pavel Kroupa 2009, MNRAS, 395, 394-400

10) Juli 2009: Nimmersatte Sternhaufen Bonner Studie zeigt, warum manche Sternhaufen immer wieder Nachwuchs bekommen

Based on Recurrent gas accretion by massive star clusters, multiple stellar populations and mass thresholds for spheroidal stellar systems : Jan Pflamm-Altenburg, Pavel Kroupa

2009, MNRAS, 397, 488-494

9) Mai 2009: Study plunges standard Theory of Cosmology into Crisis

Spiegel-Online Artikel
Simultaneous press release by the University of Vienna, Austria
Simultaneous press release by the Australian National University, Canberra

3Sat/nano TV programme (also with Simon White): link
Further 3Sat/nano TV shots and TV article: link

Examples of international media coverage:
Universe Today
Science Daily
Alpha Galileo

Based on Did the Milky Way Dwarf Satellites Enter The Halo as a Group? : Metz, Manuel; Kroupa, Pavel; Theis, Christian; Hensler, Gerhard; Jerjen, Helmut 2009, ApJ, in press

and on

Discs of satellites: the new dwarf spheroidals : Metz, Manuel; Kroupa, Pavel; Jerjen, Helmut, 2009, MNRAS, in press

See also point 15 above. See for further details on the current state of cosmology.

8) Jan. 2009: Schmelztiegel der Sternentstehung: Neue Erkenntnisse zu kleinsten Galaxien des Universums

Based on A top-heavy stellar initial mass function in starbursts as an explanation for the high mass-to-light ratios of ultra compact dwarf galaxies : Joerg Dabringhausen, Pavel Kroupa, Holger Baumgardt, 2009, MNRAS, in press

7) Oct. 2008: Mehr Sternengeburten: Astronomen haben sich verschaetzt

Based on Clustered star formation as a natural explanation for the Halpha cut-off in disk galaxies: Jan Pflamm-Altenburg, Pavel Kroupa, 2008, Nature, Volume 455, pp. 641-643

6) August 2008: Stellare Totgeburten

Based on A discontinuity in the low-mass IMF - the case of high multiplicity: Ingo Thies, Pavel Kroupa, 2008, MNRAS, Volume 390, pp. 1200-1206

5) July 2007: Sternentanz ums Schwarze Loch

Based on Origin of the S Stars in the Galactic Center : Ulf Loeckmann, Holger Baumgardt, Pavel Kroupa, 2008, ApJ, Volume 683, pp. L151-L154

4) Oct. 2007: Leben und Sterben im Universum: Bonner Astronomen simulieren am Computer, wie Sternhaufen entstehen und zerfallen

Spiegel-Online article

Based on A comprehensive set of simulations studying the influence of gas expulsion on star cluster evolution: Holger Baumgardt, Pavel Kroupa, 2008, MNRAS, Volume 380, pp. 1589-1598

3) May 2007: Raetselhaftes Band aus Milch

International conference on the Millky Way halo, organised at the AIfA from May 29th unitl June 2nd, 2007.

2) May 2006: Bonner Astronomen simulieren die Wiege des Sonnensystems


1) Dec. 2005: Sturzgeburt im Nebel

Based on Induced planet formation in stellar clusters: a parameter study of star-disc encounters : Ingo Thies, Pavel Kroupa, Christian Theis, 2005, MNRAS, Volume 364, pp. 961-970

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