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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

37768 results found.

  1. GRB 240501B: GRBAlpha detection
  2. GRB 240430A: GRBAlpha detection
  3. GRB 240502B: Fermi GBM Final Real-time Localization
  4. GRB 240502A long GRB detected by INTEGRAL
  5. GRB 240502A: Fermi GBM Final Real-time Localization
  6. Fermi GRB 240501A: Global MASTER-Net observations report
  7. Fermi trigger No 736197684: Global MASTER-Net observations report
  8. GRB 240426A: VZLUSAT-2 detection
  9. GRB 240425A: VZLUSAT-2 detection
  10. GRB240430A: Fermi GBM Final Localization
  11. GRB 240501B: AstroSat CZTI detection
  12. GRB 240501A: Fermi GBM Final Real-time Localization
  13. GRB 240408B: VZLUSAT-2 detection
  14. GRB 240407A: VZLUSAT-2 detection
  15. X-ray transient EP240414a: Detection of associated supernova
  16. GRB 240425A: GRBAlpha detection
  17. Fermi-LAT gamma-ray observations of IceCube-240424A
  18. GRB 240429A: Fermi GBM Final Real-time Localization
  19. Fermi GRB 240428A: Global MASTER-Net observations report
  20. GRB 240428A: Fermi GBM Final Real-time Localization
  21. GRB 240426A: AstroSat CZTI detection
  22. GRB 240414A: NOEMA detection
  23. LIGO/Virgo/KAGRA S240422ed: Upper limits from GECAM Observations
  24. GRB 240425A: Fermi GBM Final Real-time Localization
  25. Fermi trigger No 735697285: Global MASTER-Net observations report
  26. GRB 240419B: Swift-BAT refined analysis
  27. GRB 240421B: Swift-BAT refined analysis
  28. GRB 240422A: Glowbug gamma-ray detection
  29. IceCube-240424A - IceCube observation of a high-energy neutrino candidate track-like event
  30. GRB 240421B: GRBAlpha detection
  31. GRB 240419A: Swift-BAT refined analysis
  32. GRB 240418A: Swift-BAT refined analysis
  33. LXT240402A/GRB240402B: Chandra X-ray detection
  34. GRB 240419A: Possible ATCA radio detection
  35. GRB 240421B: ATCA radio observations
  36. LIGO/Virgo S240422ed: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  37. LIGO/Virgo/KAGRA S240422ed: AstroSat CZTI non-detection and upper limits
  38. LIGO/Virgo/KAGRA S240422ed: Upper limits from Fermi-GBM Observations
  39. LIGO/Virgo/KAGRA S240421ar: Upper limits from Swift/BAT-GUANO
  40. Fermi trigger No 735470374: Global MASTER-Net observations report
  41. GRB 240421A: Glowbug gamma-ray detection
  42. GRB 240414A: radio detection with the VLA
  43. Fermi-LAT gamma-ray observations of IceCube-240419A
  44. GRB 240414A: AMI-LA radio observations
  45. GRB 240414A: LBT optical detection
  46. GRB 240419B : MITSuME Akeno optical upper limits
  47. GRB 240415B: Swift-XRT observations
  48. GRB 240415A: Swift-XRT refined Analysis
  49. Fermi GRB 240422A: Global MASTER-Net observations report
  50. GRB 240421B: AstroSat CZTI detection
  51. GRB 240422A: Fermi GBM Final Real-time Localization
  52. GRB240421B: Zadko Observations
  53. Fermi GRB 240421B: Global MASTER-Net observations report
  54. Swift GRB 240421B: Global MASTER-Net observations report
  55. GRB 240421B: Fermi GBM Observation
  56. GRB 240421B: Swift-XRT refined Analysis
  57. GRB240421B: BOOTES-5/JGT optical upper limit
  58. GRB 240421B: J-band upper limits from WINTER
  59. GRB 240421B: Swift/UVOT Upper Limits
  60. GRB 240421B: Enhanced Swift-XRT position
  61. Fermi GRB 240421A: Global MASTER-Net observations report
  62. GRB 240421B: Swift detection of a burst
  63. EP240420a: Nanshan optical counterpart observations
  64. GRB 240421A: Fermi GBM Final Real-time Localization
  65. Fermi trigger No 735280430: Global MASTER-Net observations report
  66. GRB240419A: Skynet Optical Afterglow Analysis
  67. GRB240418A - Candidate afterglow from NIRES
  68. GRB 240419B: Swift/UVOT Upper Limits
  69. IceCube-240419A - IceCube observation of a high-energy neutrino candidate track-like event
  70. IceCube-240419A - IceCube observation of a high-energy neutrino candidate track-like event
  71. GRB 240419A: Swift/UVOT Upper Limits
  72. GRB 240419B: Swift-XRT refined Analysis
  73. GRB 240419B: optical afterglow from the NOT
  74. Swift GRB 240419B: Global MASTER-Net observations report
  75. EP240414A: Terskol Zeiss-2000 optical upper limit
  76. GRB 240419B: Enhanced Swift-XRT position
  77. Swift GRB 240419A: Global MASTER-Net observations report
  78. GRB 240418A: Swift/UVOT Upper Limits
  79. GRB 240419A: REM NIR afterglow detection
  80. GRB 240419A: Swift-XRT refined Analysis
  81. GRB 240418A: Swift-XRT refined Analysis
  82. GRB 240419B: Swift detection of a burst
  83. GRB 240411B: Swift/UVOT Detection
  84. GRB240418A: YAHPT Upper Limits
  85. GRB 240419A: VLT/UVES redshift of z = 5.178
  86. GRB 240419A: VLT optical afterglow detection
  87. GRB 240419A: Enhanced Swift-XRT position
  88. Fermi trigger No 735089036: Global MASTER-Net observations report
  89. GRB 240419A: Prompt enhanced Swift-XRT position
  90. GRB 240419A: Swift detection of a burst
  91. GRB 240418A: TSHAO Zeiss-1000 optical upper limit
  92. GRB 240418A: NOT optical upper limits
  93. GRB 240418A: Enhanced Swift-XRT position
  94. GRB 240418A: AKO Upper Limit
  95. GRB 240411A: GOTO early optical upper limits
  96. GRB 240418A: Swift detection of a burst
  97. Fermi GRB 240417A: Global MASTER-Net observations report
  98. EP240416A: Terskol Zeiss-2000 optical upper limit
  99. EP240416A: Khureltogoot optical upper limit
  100. Improved IPN triangulation of GRB 240411A

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