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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"

36211 results found.

  1. GRB 240425A: GRBAlpha detection
  2. GRB 240429A: Fermi GBM Final Real-time Localization
  3. Fermi GRB 240428A: Global MASTER-Net observations report
  4. GRB 240428A: Fermi GBM Final Real-time Localization
  5. GRB 240426A: AstroSat CZTI detection
  6. EP240426a: YAHPT optical upper limit
  7. GRB 240414A: NOEMA detection
  8. IceCube-240424A: Upper limits from a search for additional neutrino events in IceCube
  9. LIGO/Virgo/KAGRA S240422ed: Upper limits from GECAM Observations
  10. GRB 240425A: Fermi GBM Final Real-time Localization
  11. GRB 240419B: Swift-BAT refined analysis
  12. GRB 240421B: Swift-BAT refined analysis
  13. GRB 240422A: Glowbug gamma-ray detection
  14. IceCube-240424A - IceCube observation of a high-energy neutrino candidate track-like event
  15. GRB 240421B: GRBAlpha detection
  16. IceCube-240419A: Upper limits from a search for additional neutrino events in IceCube
  17. GRB 240419A: Swift-BAT refined analysis
  18. GRB 240418A: Swift-BAT refined analysis
  19. LXT240402A/GRB240402B: Chandra X-ray detection
  20. GRB 240419A: Possible ATCA radio detection
  21. GRB 240421B: ATCA radio observations
  22. LIGO/Virgo S240422ed: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  23. LIGO/Virgo/KAGRA S240422ed: AstroSat CZTI non-detection and upper limits
  24. LIGO/Virgo/KAGRA S240422ed: Upper limits from Fermi-GBM Observations
  25. LIGO/Virgo/KAGRA S240421ar: Upper limits from Swift/BAT-GUANO
  26. GRB 240421A: Glowbug gamma-ray detection
  27. GRB 240414A: radio detection with the VLA
  28. GRB 240414A: AMI-LA radio observations
  29. GRB 240414A: LBT optical detection
  30. GRB 240419B : MITSuME Akeno optical upper limits
  31. GRB 240415B: Swift-XRT observations
  32. GRB 240415A: Swift-XRT refined Analysis
  33. Fermi GRB 240422A: Global MASTER-Net observations report
  34. GRB 240421B: AstroSat CZTI detection
  35. GRB 240422A: Fermi GBM Final Real-time Localization
  36. GRB240421B: Zadko Observations
  37. Fermi GRB 240421B: Global MASTER-Net observations report
  38. Swift GRB 240421B: Global MASTER-Net observations report
  39. GRB 240421B: Fermi GBM Observation
  40. GRB 240421B: Swift-XRT refined Analysis
  41. GRB240421B: BOOTES-5/JGT optical upper limit
  42. GRB 240421B: J-band upper limits from WINTER
  43. GRB 240421B: Swift/UVOT Upper Limits
  44. GRB 240421B: Enhanced Swift-XRT position
  45. Fermi GRB 240421A: Global MASTER-Net observations report
  46. GRB 240421B: Swift detection of a burst
  47. EP240420a: Nanshan optical counterpart observations
  48. GRB 240421A: Fermi GBM Final Real-time Localization
  49. GRB240419A: Skynet Optical Afterglow Analysis
  50. GRB240418A - Candidate afterglow from NIRES
  51. GRB 240419B: Swift/UVOT Upper Limits
  52. GRB 240419A: Swift/UVOT Upper Limits
  53. GRB 240419B: Swift-XRT refined Analysis
  54. GRB 240419B: optical afterglow from the NOT
  55. Swift GRB 240419B: Global MASTER-Net observations report
  56. EP240414A: Terskol Zeiss-2000 optical upper limit
  57. GRB 240419B: Enhanced Swift-XRT position
  58. Swift GRB 240419A: Global MASTER-Net observations report
  59. GRB 240418A: Swift/UVOT Upper Limits
  60. GRB 240419A: REM NIR afterglow detection
  61. GRB 240419A: Swift-XRT refined Analysis
  62. GRB 240418A: Swift-XRT refined Analysis
  63. GRB 240419B: Swift detection of a burst
  64. GRB 240411B: Swift/UVOT Detection
  65. GRB240418A: YAHPT Upper Limits
  66. GRB 240419A: VLT/UVES redshift of z = 5.178
  67. GRB 240419A: VLT optical afterglow detection
  68. GRB 240419A: Enhanced Swift-XRT position
  69. GRB 240419A: Prompt enhanced Swift-XRT position
  70. GRB 240419A: Swift detection of a burst
  71. GRB 240418A: TSHAO Zeiss-1000 optical upper limit
  72. GRB 240418A: NOT optical upper limits
  73. GRB 240418A: Enhanced Swift-XRT position
  74. GRB 240418A: AKO Upper Limit
  75. GRB 240411A: GOTO early optical upper limits
  76. GRB 240418A: Swift detection of a burst
  77. Fermi GRB 240417A: Global MASTER-Net observations report
  78. EP240416A: Terskol Zeiss-2000 optical upper limit
  79. EP240416A: Khureltogoot optical upper limit
  80. Improved IPN triangulation of GRB 240411A
  81. GRB 240417A: Fermi GBM Final Real-time Localization
  82. GRB 240415A: Glowbug gamma-ray detection
  83. GRB 240414A: Glowbug gamma-ray detection
  84. GRB 240415B: GECAM-B detection
  85. EP 240416a: Xinglong and NOT decaying optical counterpart
  86. GRB 240415A: Swift-BAT refined analysis
  87. GRB 240411A: Glowbug gamma-ray detection
  88. GRB 240414A: Swift-BAT refined analysis
  89. GRB 240414A: AbAO optical upprer limit
  90. GRB 240415A: Swift/UVOT Detection
  91. GRB 240415A: Fermi GBM Observation
  92. GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
  93. GRB 240415A: Earliest optical followup with the Kinder observations
  94. GRB 240414A: GMG observation
  95. GRB 240415A: Enhanced Swift-XRT position
  96. GRB 240415B: Swift ToO observations
  97. GRB 240415B: Swift/BAT-GUANO Correction
  98. GRB 240415B: Swift/BAT-GUANO arcminute localization of a short burst
  99. GRB 240415A: OHP/T193 optical observations
  100. GRB 240415A: optical afterglow detection from the INAF Asiago Observatory

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