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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

41741 results found.

  1. GRB 151022A: Kanata/HOWPol optical observation
  2. GRB 151022A: MASTER-Ural observations
  3. GRB 151022A: Swift detection of a burst
  4. GRB 151021A: MITSuME Okayama Ks-band upper-limit
  5. GRB 151021B: Fermi GBM detection
  6. Konus-Wind observation of GRB 151021A
  7. GRB 151021A: Swift/UVOT Detection
  8. GRB 151021A: MITSuME Okayama upper limits
  9. GRB 151021A: Swift-XRT refined Analysis
  10. GRB 151021A: Swift-BAT refined analysis
  11. GRB 151021A: MASTER-NET bright OT detection
  12. GRB 151021A: Optical counterpart and redshift from X-shooter
  13. GRB 151021A: Swift detection of a burst
  14. LIGO/Virgo G184098: LOFAR follow-up
  15. GRB 151004A: Swift-XRT follow-up observations
  16. GRB 151006A: Astrosat CZTI detection
  17. Trigger 659734: Swift detection of SAX J1750.8-2900 or other source near Galactic center
  18. LIGO/Virgo G184098: VLA follow-up of iPTF15cyk
  19. Fermi GBM trigger 466602792/151015495 is not a GRB
  20. LIGO/VIRGO G184098 : PESSTO classifications of PanSTARRS transients in the northern region
  21. Fermi GBM trigger 466316973/151012187 is not a GRB
  22. GRB 151006A: Mondy optical upper limit
  23. GRB 151006A: MITSuME Akeno optical upper limits
  24. Fermi GBM trigger 466059859/151009211 is not a GRB
  25. Konus-Wind observation of GRB 151006A
  26. GRB 151006A: OSN optical upper limit
  27. GRB 151006A: Swift-BAT refined analysis
  28. GRB 151006A: MITSuME Okayama Ks-band upper-limit
  29. GRB 151006A: Swift-XRT refined Analysis
  30. GRB 151006A: Fermi-LAT detection
  31. GRB 151006A: Swift/UVOT Upper Limits
  32. GRB 151006A: Fermi GBM detection
  33. GRB 151006A: MITSuME Okayama upper limits
  34. Konus-Wind observation of GRB 151001B
  35. GRB 151006A: Kanata/HOWPol optical imaging polarimetry
  36. GRB 151006A: Swift detection of a burst
  37. LIGO/Virgo G184098: Further VST-ESO PARANAL observations
  38. Trigger 657564 / GRB 151004A: Swift BAT and XRT refined analysis
  39. LIGO/VIRGO G184098 : PESSTO classification of PS15cbm in the northern region
  40. LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
  41. Trigger 657564 / GRB 151004A: Swift/UVOT Upper Limits
  42. Swift Trigger 657564: MASTER-NET early optical observations.
  43. Swift Trigger 657564: XRT prompt analysis
  44. LIGO/Virgo G184098: MASTER OTs detection and Scenario Machine prediction
  45. Swift Trigger 657564: a probable GRB
  46. LIGO/Virgo G184098: Ongoing gravitational-wave analysis
  47. GRB 151001A: Swift-BAT refined analysis
  48. GRB 151001A: RATIR Observations
  49. GRB 151001B: Swift/UVOT Upper Limits
  50. GRB 151001B: Swift-XRT refined Analysis
  51. GRB 151001B: Swift-BAT refined analysis
  52. GRB 151001A: Swift/UVOT Detection
  53. GRB 151001B: MASTER-NET early optical observations.
  54. GRB 151001A: NOT imaging
  55. GRB 151001A: Swift-XRT refined Analysis
  56. GRB 151001A: Fermi GBM detection
  57. GRB 151001B: Swift detection of a burst
  58. GRB 151001A: Swift detection of a burst with an optical counterpart
  59. LIGO/Virgo G184098: spectral classification of PS15cci
  60. LIGO/Virgo G184098: Update to LT Spectroscopy of PS15ccx
  61. LIGO/Virgo G184098: Liverpool Telescope Spectroscopy of PS15ccx
  62. GRB 150925A: Swift/UVOT Upper Limits
  63. GRB 150925A: Swift-BAT refined analysis
  64. GRB 150925A: Swift-XRT refined Analysis
  65. GRB 150925A: Swift detection of a burst
  66. LIGO/Virgo G184098: LOFAR follow-up
  67. LIGO/Virgo G184098: ASKAP followup
  68. LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
  69. LIGO/Virgo G184098: optical transient search with Kiso Schmidt telescope and KWFC on behalf of J-GEM collaboration
  70. Konus-Wind observation of GRB 150922A
  71. LIGO/VIRGO G184098 : classifications of transients from the LSQ observations
  72. GRB 150922A: Fermi GBM observation
  73. IPN Triangulation of GRB 150922A (short/hard)
  74. Konus-Wind observation of GRB 150919A
  75. IPN Triangulation of GRB 150919A (short / hard)
  76. LIGO/Virgo G184098: INTEGRAL search of temporally coincident prompt hard X-ray emission
  77. LIGO/Virgo G184098: transient search with VISTA
  78. ANTARES neutrino detection: Fermi GBM Observations
  79. Fermi GBM trigger bn150920977 is not due to a GRB
  80. LIGO/Virgo G184098: DESGW followup program
  81. LIGO/Virgo G184098: SkyMapper observations
  82. LIGO/Virgo G184098: TAROT network optical observations
  83. LIGO/Virgo G184098: La Silla - QUEST Followup
  84. LIGO/Virgo G184098: Swift follow-up observations
  85. LIGO/Virgo G184098: MWA Followup
  86. LIGO/Virgo G184098: DESGW followup program
  87. LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
  88. LIGO/Virgo observing run 1 (O1) starts 2015-09-18 15:00 UTC
  89. LIGO/Virgo G184098: Keck II DEIMOS Spectra of iPTF Optical Candidates
  90. LIGO/Virgo G184098: Nearby Galaxies in Error Circle
  91. LIGO/Virgo G184098: Fermi-GBM ground-based follow-up
  92. LIGO/Virgo G184098: Observations from the TOROS collaboration
  93. LIGO/Virgo G184098: iPTF Optical Transient Candidates
  94. LIGO/Virgo G184098: VST-ESO PARANAL observations
  95. LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
  96. Instructions for reporting follow-up observations related to LIGO/Virgo G184098
  97. LIGO/Virgo G184098: observations by MASTER
  98. LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
  99. LIGO/Virgo G184098: Swift follow-up observations
  100. LIGO/Virgo G184098: Burst candidate in LIGO engineering run data

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