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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"

4256 results found.

  1. Trigger 686761: Swift detection of a bright burst from SGR 1935+2154
  2. Fermi GBM trigger 485124591/160516868 is not a GRB
  3. Trigger 686443: Swift detection of SGR 1935+2154
  4. Fermi GBM trigger 484906918/160514349 is not a GRB
  5. FACT follow-up of the IceCube event 160427A
  6. Interplanetary Network Search for IceCube 160427A
  7. LIGO/Virgo G211117: Astrosat CZTI upper limits
  8. GRB 160506A: Swift detection of a burst
  9. MASTER search for counterpart to the IceCube event 67093193 (run 127853)
  10. GRB 160425A: SMARTS optical/IR observations
  11. GRB 160425A: Swift detection of an unusual burst with an optical afterglow
  12. LIGO/Virgo G211117: LOFAR follow-up
  13. GRB 160325A: GROND Upper Limits
  14. SGR 0755-2933, Swift-BAT refined analysis
  15. Swift detection of a likely new SGR: SGR 0755-2933
  16. LIGO/Virgo G194575: EWE for NOWT follow-up of northern sky
  17. GRB 160314A: Swift detection of a burst
  18. LIGO/Virgo G211117: GRAWITA LBT follow-up of PS15dpn
  19. GRB 160228A: GROND Afterglow Candidate
  20. GRB 160220A: MASTER-Amur observations
  21. LIGO/Virgo G184098: Correction for GCN Circular 18361
  22. LIGO/Virgo G211117: LOFAR follow-up
  23. GRB 160206B: iPTF P48 Observations and Optical Transient Candidates
  24. GRB 160131A: Mondy optcial observations
  25. GRB 160131A: MITSuME Ishigakijima Optical Observation
  26. GRB 160131A: Khureltogot optical observations
  27. GRB 160131A: Xinglong 60cm WFT optical observation
  28. GRB 160121A: TSHAO optical afterglow confirmation
  29. GRB 151228B: AbAO optical upper limit
  30. GRB 160117B: GROND optical/NIR afterglow observations
  31. LIGO/Virgo G211117: VISTA imaging
  32. LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
  33. LIGO/Virgo G211117: Summary of Pan-STARRS transients
  34. LIGO/Virgo G211117: LOFAR follow-up
  35. LIGO/Virgo G211117: CSS/CRTS observations on 29/30 Dec 2015 UT
  36. LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
  37. LIGO/Virgo G211117: Liverpool Telescope followup of EM candidates
  38. LIGO/Virgo G211117: OAO-WFC NIR follow-up observations
  39. GRB 151229A: MITSuME Akeno optical upper limits
  40. LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
  41. LIGO/Virgo G211117: List of near-term future observation regions by Project Mini-GWAC of SVOM
  42. LIGO/Virgo G211117: iPTF Optical Transient Candidates
  43. GRB 151229A: MITSuME Okayama upper limits
  44. LIGO/Virgo G211117: La Silla - QUEST observations 2015 Dec 28, 29
  45. GRB 151228B: MITSuME Akeno optical upper limits
  46. GRB 151229A: Fermi GBM observation
  47. GRB 151228B: Fermi GBM observation
  48. LIGO/Virgo G211117: Further Swift-XRT sources
  49. LIGO/Virgo G211117: Optical follow-up with Kanata telescope
  50. LIGO/Virgo G211117: INAF VST-ESO PARANAL observations
  51. IBAS Alert 7313 is SGR J1935+2154
  52. GRB 151221A: INTEGRAL detection of a short burst or possible SGR
  53. GRB 151216A: MAXI/GSC detection
  54. GRB 151205C: Optical follow-up observations at Kiso
  55. GRB 130831A: MASTER early OT detection and LC
  56. GRB 151205C: MAXI/GSC detection
  57. Fermi GBM trigger 470712580/151202062 is not a GRB
  58. Swift-BAT refined analysis of trigger 664624 from SGR J1819-1600
  59. Swift-BAT probable detection of an outburst from SGR J1819-1600 (AX J1818.8-1559)
  60. GRB 151120A: Swift-XRT afterglow detection
  61. Swift-BAT trigger 663164 is not a burst.
  62. GRB 151027A: Mondy optical observations
  63. LIGO/Virgo G194575: LT Spectroscopy of iPTF candidates
  64. LIGO/Virgo G194575: INAF-TNG follow-up of iPTF15dkm and iPTF15dlj
  65. GRB 151029A: MITSuME Ishigakijima upper limits
  66. GRB 151029A: LCOGT-FTS afterglow observations
  67. LIGO/Virgo G194575: VLA follow-up
  68. GRB 151029A: GROND afterglow observations
  69. GRB 151027A: LCOGT-McDonald afterglow observations
  70. LIGO/Virgo G194575: further Pan-STARRS observations of the RA=1hr localisation region
  71. LIGO/Virgo G194575: Near-infrared follow-up with OAO-WFC
  72. LIGO/Virgo G194575: MAXI/GSC observations
  73. GRB 151021A: Swift detection of a burst
  74. Fermi GBM trigger 466316973/151012187 is not a GRB
  75. Konus-Wind observation of GRB 151001B
  76. LIGO/Virgo G184098: Further VST-ESO PARANAL observations
  77. GRB 151001B: Swift detection of a burst
  78. IPN Triangulation of GRB 150922A (short/hard)
  79. LIGO/Virgo G184098: TAROT network optical observations
  80. LIGO/Virgo G184098: Observations from the TOROS collaboration
  81. LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
  82. GRB 150911A: WHT optical imaging
  83. GRB 150910A: MITSuME Ishigakijima Optical Observation after 1 day
  84. GRB 150910A: Swift detection of a burst with an optical afterglow
  85. GRB 150907B: MASTER-SAAO early optical observations
  86. GRB 150906A: Fermi GBM detection
  87. GRB 150902A: Swift-XRT observations
  88. GRB 150831B: MASTER-IAC early optical observations
  89. Fermi GBM trigger 150829183 is not a GRB
  90. Fermi GBM trigger 150828520 is not a GRB
  91. Konus-Wind observation of GRB 150818A
  92. IPN Triangulation of GRB 150819B (short / very intense)
  93. Fermi GBM GRB Trigger 458852670: iPTF P48 Observations
  94. GRB 150728A: TSHAO optical observations
  95. Trigger 650221: Swift detection of a IGR J00291+5934
  96. SGR 1E 1841-045 (Swift trigger 649113): Terskol upper limit
  97. Trigger 649113: Swift detection of SGR 1E 1841-045
  98. Swift-XRT observations of GRB 150710A
  99. Fermi Gamma-ray Burst Monitor trigger bn150629779 is not a GRB
  100. GRB 150627A: Swift/UVOT Detection

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