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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"

3397 results found.

  1. GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger
  2. INTEGRAL detection of a burst from SGR J1935+2154
  3. Konus-Wind detection of GRB 221009A
  4. GRB221009A/Swift J1913.1+1946: ATA follow-up observations
  5. GRB 221006A: Swift-XRT observations
  6. GRB 220921A: ATCA detection of radio counterpart
  7. Fermi trigger No 686403226: Global MASTER-Net observations report
  8. Fermi trigger No 686350260: Global MASTER-Net observations report
  9. Fermi-LAT gamma-ray observations of IceCube-220928A
  10. IceCube-220928A: Upper limits from a search for additional neutrino events in IceCube
  11. IceCube-220928A - IceCube observation of a high-energy neutrino candidate track-like event
  12. IPN triangulation of GRB 220927A (long)
  13. Fermi GRB 220925A: Global MASTER-Net observations report
  14. Fermi trigger No 685748699: Global MASTER-Net observations report
  15. LAT GRB220921.46: Global MASTER-Net observations report
  16. Fermi trigger No 685452089: Global MASTER-Net observations report
  17. Fermi trigger No 684716840: Global MASTER-Net observations report
  18. Fermi GRB 220912A: Global MASTER-Net observations report
  19. IPN triangulation of GRB 220905A
  20. IceCube Alert 220907.28: Global MASTER-Net observations report
  21. GRB 220905A: BALROG localization (Fermi Trigger 684070128 / GRB 220905478)
  22. GRB 220905A: Fermi GBM Final Real-time Localization
  23. Fermi trigger No 683646997: Global MASTER-Net observations report
  24. Fermi trigger No 683537972: Global MASTER-Net observations report
  25. Fermi trigger No 683202084: Global MASTER-Net observations report
  26. Fermi trigger No 683183601: Global MASTER-Net observations report
  27. GRB 220823A: Fermi GBM detection
  28. Fermi trigger No 682918137: Global MASTER-Net observations report
  29. GRB 220823A: Swift/BAT-GUANO detection of a short burst
  30. IceCube Alert 220822.85: Global MASTER-Net observations report
  31. Fermi GRB 220810A: Global MASTER-Net observations report
  32. Fermi trigger No 681212354: Global MASTER-Net observations report
  33. Fermi trigger No 680782656: Global MASTER-Net observations report
  34. Fermi GRB 220728A: Global MASTER-Net observations report
  35. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220728A
  36. GRB 220728A: Fermi GBM Final Real-time Localization
  37. Fermi GRB 220724A: Global MASTER-Net observations report
  38. GRB 220715B: Fermi GBM detection
  39. GRB 220714B: Fermi GBM observation
  40. Fermi GRB 220711B: Global MASTER-Net observations report
  41. GRB 220711B: NOT optical observations
  42. GRB 220711B: Swift detection of a burst
  43. GRB 220711B: Fermi GBM Final Real-time Localization
  44. GRB 220708A: Swift detection of a burst
  45. GRB 220706A: Swift detection of a burst
  46. IceCube-220629A: Upper limits from a search for additional neutrino events in IceCube
  47. IceCube-220629A: No significant detection in HAWC
  48. IceCube-220627A: No significant detection in HAWC
  49. IceCube-220627A: Upper limits from a search for additional neutrino events in IceCube
  50. Swift XRT observations of WISEA J145820.77+412101.9 / IceCube 220624A
  51. GRB 220627A: MeerLICHT candidate optical afterglow
  52. GRB 220627A: Fermi GBM Detection of a possible Lensed or Ultra-long GRB
  53. Fermi trigger No 678058621: Global MASTER-Net observations report
  54. Fermi GRB 220623B: Global MASTER-Net observations report
  55. Swift Detection of MAXI J0655-013
  56. Fermi trigger No 677377371: Global MASTER-Net observations report
  57. Fermi GRB 220620A: Global MASTER-Net observations report
  58. GRB 220617A: Swift-XRT observations
  59. IPN triangulation of GRB 220606C
  60. Fermi trigger No 676909037: Global MASTER-Net observations report
  61. Fermi trigger No 676537486: Global MASTER-Net observations report
  62. Fermi GRB 220608A: Global MASTER-Net observations report
  63. Konus-Wind detection of GRB 220601A
  64. GRB 220606B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  65. GRB 220606B: Fermi GBM Final Real-time Localization
  66. Fermi trigger No 675992935: Global MASTER-Net observations report
  67. GRB 220527A: MITSuME Akeno continued optical observation
  68. GRB 220527A: Lick 3m Optical Observations
  69. GRB 220528A: Fermi GBM Observation
  70. Fermi GRB 220530A: Global MASTER-Net observations report
  71. GRB 220528A: Fermi GBM Final Localization
  72. GRB 220527A: REM optical/NIR observations
  73. GRB 220527A: VLT/X-shooter spectroscopic redshift
  74. Fermi trigger No 675411172: Global MASTER-Net observations report
  75. GRB 220527A: NOT optical photometry and spectroscopic redshift
  76. IPN triangulation of GRB 220522B
  77. GRB 220521A: ISON-Castelgrande observatory optical observations
  78. IPN triangulation of GRB 220519A
  79. Konus-Wind detection of GRB 220506A
  80. GRB 220514B: MAXI/GSC detection
  81. IceCube-220513A: No Candidate Counterparts from the Zwicky Transient Facility
  82. IceCube Alert 220513.97: Global MASTER-Net observations report
  83. Fermi GRB 220513A: Global MASTER-Net observations report
  84. GRB 220506A: MITSuME Akeno optical upper limits
  85. IceCube Alert 220509.76: Global MASTER-Net observations report
  86. GRB 220506A/MAXI J1558-266: MAXI/GSC detection
  87. IceCube-220421A: Upper limits from a search for additional neutrino events in IceCube
  88. GRB 220423A: Detection by VZLUSAT-2
  89. Fermi GRB 220426B: Global MASTER-Net observations report
  90. Fermi trigger No 672374264: Global MASTER-Net observations report
  91. Fermi trigger No 671729344: Global MASTER-Net observations report
  92. Konus-Wind detection of GRB 220412B
  93. GRB 220408B: Fermi GBM observation
  94. Konus-Wind detection of GRB 220408B
  95. GRB 220412A: Continued RATIR Observations and Steepening of the Light Curve
  96. GRB 220408B: Fermi-LAT detection
  97. GRB 220412B: MITSuME Akeno optical upper limits
  98. IPN triangulation of GRB 220408B
  99. Fermi GRB 220411A: Global MASTER-Net observations report
  100. GRB 220408B: AstroSat CZTI detection

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