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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"

35423 results found.

  1. GRB 240527A: Fermi GBM Final Real-time Localization
  2. GRB 240523A: Swift-BAT refined analysis
  3. GRB 240523A: Swift-XRT refined Analysis
  4. GRB 240523A: Enhanced Swift-XRT position
  5. GRB 240523A: Swift detection of a burst
  6. GRB 240521B: Fermi GBM Observation
  7. Fermi GBM Sub-Threshold Detection of GRB 240516B
  8. GRB 240513A: Swift-XRT afterglow detection
  9. GRB 240521B: Swift/BAT-GUANO arcminute localization of a long burst
  10. GRB 240521A: GECAM-B detection of a long burst
  11. GRB 240516B: AstroSat CZTI detection
  12. LIGO/Virgo/KAGRA S240515m: Upper limits from Swift/BAT-GUANO
  13. LIGO/Virgo/KAGRA S240514x: Upper limits from Swift/BAT-GUANO
  14. LIGO/Virgo/KAGRA S240513ei: Upper limits from Swift/BAT-GUANO
  15. GRB 240514B: VZLUSAT-2 detection
  16. GRB 240504A: VZLUSAT-2 detection
  17. GRB 240502A: VZLUSAT-2 detection
  18. GRB 240519A: GRBAlpha detection
  19. GRB 240516A: Swift/UVOT Upper Limits
  20. GRB 240519A: AstroSat CZTI detection
  21. GRB 240519A: BALROG localization (Fermi Trigger 737788024 / GRB 240519213)
  22. GRB 240516A: Swift-BAT refined analysis
  23. Fermi GRB 240517A: Global MASTER-Net observations report
  24. GRB 240516A ATCA radio observations
  25. IPN triangulation of GRB 240514B (short)
  26. GRB 240513A: Swift ToO observations
  27. GRB 240517A: Fermi GBM Final Real-time Localization
  28. Konus-Wind detection of GRB 240513A
  29. GRB 240516A: AstroSat CZTI detection
  30. GRB 240516A: Swift-XRT refined Analysis
  31. GRB 240514E: A possible candidate BD-21 1074
  32. GRB 240516A: Fermi GBM Observation
  33. GRB 240511A: Observations from GTC/OSIRIS+
  34. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  35. GRB 240516A: GOTO optical upper limit
  36. LIGO/Virgo/KAGRA S240422ed: GRID non-detection and upper limits
  37. GRB 240516A: Swift detection of a burst
  38. GRB 240514B: AT2024ixa/GOTO24bph is not consistent with the Fermi localisation
  39. GRB 240511A: radio detection of afterglow candidate
  40. GRB 240514B: GOTO candidate optical counterpart
  41. Fermi Gamma-ray Burst Monitor list of triggers that are not a GRB
  42. GRB 240514E: MAXI/GSC detection of a probable afterglow
  43. GRB 240514B: GRBAlpha detection
  44. GRB 240514B: Fermi GBM Detection
  45. GRB 240513A: Fermi GBM observation
  46. GRB 240513A: Swift-XRT observations
  47. GRB 240514D: AstroSat CZTI detection
  48. GRB 240514C: Fermi GBM Final Real-time Localization
  49. Fermi GRB 240514B: Global MASTER-Net observations report
  50. GRB 240514B: Fermi GBM Final Real-time Localization
  51. LIGO/Virgo/KAGRA S240507p: Upper limits from Swift/BAT-GUANO
  52. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  53. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  54. GRB 240514A: Fermi GBM Final Real-time Localization
  55. GRB 240513A: Tiled Swift observations
  56. GRB 240513A: Fermi-LAT detection
  57. GRB 240511A: Fermi GBM Observation
  58. GRB 240511A: Swift-BAT refined analysis
  59. Fermi GRB 240513B: Global MASTER-Net observations report
  60. GRB 240513B: Fermi GBM Final Real-time Localization
  61. GRB 240513A: AstroSat CZTI detection
  62. GRB 240511A: J-band observations with WINTER
  63. GRB 240511A: Enhanced Swift-XRT position
  64. GRB 240511A : MITSuME Akeno optical upper limits
  65. GRB 240511A: Swift-XRT refined Analysis
  66. GRB 240511A: optical afterglow detection from the NOT
  67. Fermi Gamma-ray Burst Monitor trigger 737102480/240511279 is not a GRB
  68. Fermi Gamma-ray Burst Monitor trigger 737111207/240511380 is not a GRB
  69. Fermi GBM trigger 737105243/240511311 is not a GRB
  70. Fermi GRB 240511A: Global MASTER-Net observations report
  71. Swift GRB 240511A: Global MASTER-Net observations report
  72. Fermi Gamma-ray Burst Monitor trigger 737133200/240511634 is not a GRB
  73. GRB 240511A: Prompt enhanced Swift-XRT position
  74. GRB 240511A: Swift detection of a burst
  75. GRB 240511A: Fermi GBM Final Real-time Localization
  76. Fermi Gamma-ray Burst Monitor trigger 737076431/240510977 is not a GRB
  77. Fermi Gamma-ray Burst Monitor trigger 230925241/717313591 is not a GRB
  78. EP240506a: CrAO ZTSH optical upper limit
  79. GRB 240504A: Fermi GBM Observation
  80. Fermi Gamma-ray Burst Monitor trigger 736837160/240508208 is not a GRB
  81. IPN triangulation of GRB 240504A
  82. GRB 240502A: 1.3m DFOT Optical upper limit
  83. GRB 240504A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  84. GRB 240502C: Zeiss-1000 at Koshka observatory observations of GOTO optical counterpart candidates
  85. IPN triangulation of GRB 240501B and GRB 240501A - possible episodes of ultra long GRB
  86. Fermi GRB 240504A: Global MASTER-Net observations report
  87. GRB 240503A: AstroSat CZTI detection
  88. GRB 240504A: BALROG localization (Fermi Trigger 736492377 / GRB 240504217)
  89. GRB 240504A: Fermi GBM Final Real-time Localization
  90. LXT 240402A / GRB 240402B: VLT X-shooter redshift of host
  91. GRB 240502A: GOTO optical upper limit
  92. GRB 240502A: Fermi GBM Observation
  93. GRB 240415A 1.3m DFOT Optical upper limit
  94. GRB 240502C: GOTO possible optical counterpart candidates
  95. Fermi GRB 240502B: Global MASTER-Net observations report
  96. GRB 240502C: Fermi GBM Final Localization
  97. Fermi GRB 240502A: Global MASTER-Net observations report
  98. GRB 240501B: GRBAlpha detection
  99. GRB 240430A: GRBAlpha detection
  100. GRB 240502B: Fermi GBM Final Real-time Localization

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