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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').
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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"

19600 results found.

  1. GRB 231118A: Swift detection of a burst
  2. GRB 231117A: GRBAlpha detection
  3. GRB 231117A: GIT optical follow-up
  4. GRB 231117A: AKO Optical Upper Limit
  5. GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
  6. Swift GRB 231117A: Global MASTER-Net observations report
  7. GRB 231117A (short): Glowbug gamma-ray detection
  8. GRB 231117A: ATLAS non-detection of an optical counterpart
  9. Konus-Wind detection of GRB 231117A (short/hard)
  10. GRB 231115A: optical observations from INAF observatories
  11. GRB 231117A : MITSuME Akeno optical upper limits
  12. GRB 231117A: AGILE detection of a bright short burst
  13. GRB 231117A: Enhanced Swift-XRT position
  14. GRB 231117A: GOTO optical upper limits
  15. GRB 231117A: AstroSat CZTI detection of a bright short burst
  16. GRB 231117A: Swift detection of a bright short burst
  17. GRB 231111A: Swift/UVOT Detection
  18. GRB 231115A: Swift/BAT-GUANO detection of a short burst
  19. GRB 231115A: Swift-XRT and Swift-UVOT observations
  20. GRB 231115A: Swift ToO observations
  21. GRB 231111A: Swift-BAT refined analysis
  22. GECAM-B observation of a short burst from SGR J1555-5402
  23. SGRJ1555-5402: Swift/BAT-GUANO arcminute localization of a SGR flare
  24. GRB 231110A: CALET Gamma-Ray Burst Monitor detection
  25. GRB 231110A: Swift-BAT refined analysis
  26. GRB231111A: MDM 2.4m Hiltner Telescope Observation
  27. GRB 231111A: Xinglong-2.16m optical observations
  28. GRB 231110A: Swift-UVOT Upper Limits
  29. GRB 231104A: VZLUSAT-2 detection
  30. GRB 231110A: Glowbug gamma-ray detection
  31. GRB 231110A: AstroSat CZTI detection
  32. GRB 231111A: Leavitt Observatory optical observations
  33. GRB231111A: Optical follow-up observations with Mephisto
  34. GRB 231111A: Osservatorio Astronomico "Nastro Verde" optical observations with detection of an optical counterpart
  35. GRB 231110A: Terskol Zeiss-2000 optical upper limit
  36. GRB 231111A: Swift-XRT refined Analysis
  37. GRB 231111A: Mondy optical observations
  38. GRB 231111A: GECAM-C detection of a long burst (correction)
  39. GRB 231110A: GECAM-B detection (correction)
  40. GRB 231111A: Enhanced Swift-XRT position
  41. GRB 231111A: GECAM-C detection of a long burst
  42. GRB 231110A: GECAM detection
  43. GRB 231110A: SAO RAS optical observations
  44. GRB 231110A: Swift-XRT afterglow detection
  45. GRB231111A: YAHPT Observations
  46. GRB231111A: GIT confirmation of the optical afterglow
  47. GRB 231111A: MASTER OT earlier detection
  48. GRB 231111A: Nanshan/HMT optical observations
  49. GRB 231111A: Swift detection of a burst with an optical counterpart
  50. Swift GRB231111.60: Global MASTER-Net observations report
  51. GRB231110A: WFST Observation and upper limits
  52. Swift GRB231110.89: Global MASTER-Net observations report
  53. GRB 231110A: Swift detection of a burst
  54. GRB 231104A: Swift-BAT refined analysis
  55. GRB 231104A: FRAM-ORM optical limit
  56. LIGO/Virgo/KAGRA S231102w: Upper limits from Swift/BAT-GUANO
  57. GRB 231104A: NuSTAR Observation of the prompt emission
  58. GRB 231104A: 3.6m DOT optical upper limit
  59. GRB 231104A: NOT upper limit
  60. GRB 231104A: Fermi GBM Observation
  61. GRB 231104A: AKO Upper Limit
  62. GRB 231104A: AstroSat CZTI detection
  63. GRB 231104A: Swift-XRT refined Analysis
  64. GRB 231104A: Fermi-LAT detection
  65. GRB 231104A: Swift/UVOT Upper Limits
  66. GRB 231104A: Enhanced Swift-XRT position
  67. GRB231104A: LCOGT Optical Upper Limits
  68. GRB 231104A: Swift detection of a bright burst
  69. Swift GRB231104.07: Global MASTER-Net observations report
  70. New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
  71. IPN triangulation of GRB 231020A
  72. GRB 231028A: Swift-BAT refined analysis
  73. LIGO/Virgo/KAGRA S231029y: Upper limits from Swift/BAT-GUANO
  74. GRB 231028A: CALET Gamma-Ray Burst Monitor detection
  75. GRB 231028A: AstroSat CZTI detection
  76. GRB 231028A: Glowbug gamma-ray detection
  77. GRB 231028A: Fermi GBM Detection
  78. Swift GRB 231028A: Global MASTER-Net observations report
  79. GRB 231028A: Swift detection of a burst
  80. GRB 231025A: Fermi GBM Observation
  81. GRB 231025A: Swift/BAT-GUANO detection of a likely short burst
  82. GRB 231018A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  83. LIGO/Virgo/KAGRA S231020bw: Upper limits from Swift/BAT-GUANO
  84. GRB 231017A: Mondy optical observations. A possible candidate for an afterglow or host galaxy.
  85. GRB 231017A: 1.3m DFOT Optical upper limit
  86. GRB 231018A: Glowbug gamma-ray detection
  87. IPN triangulation of GRB 231018A
  88. GRB 231017A: Swift/UVOT Upper Limit
  89. GRB 230911C: ATCA detection of possible radio counterpart
  90. GRB 231017A: GOTO optical upper limits
  91. GRB 231017A: JinShan optical upper limit
  92. GRB 231017A: Las Cumbres optical upper limit
  93. GRB 231017A: LCOGT Optical Upper Limits
  94. GRB231017A: GROWTH-India upper limits on the optical afterglow
  95. GRB 231017A: Fermi GBM Detection
  96. GRB 231017A: Swift-XRT observations
  97. GRB 231017A: Swift ToO observations
  98. GRB 231017A: Swift/BAT-GUANO candidate arcminute localization of a burst
  99. LIGO/Virgo/KAGRA S231014r: Upper limits from Swift/BAT-GUANO
  100. LIGO/Virgo/KAGRA S231005j: Upper limits from Swift/BAT-GUANO

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