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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"

45740 results found.

  1. GRB 240529A: AKO Optical Afterglow Detection
  2. LIGO/Virgo/KAGRA S240530a: Identification of a GW compact binary merger candidate
  3. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  4. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  5. GRB 240529A: J-band detections with WINTER
  6. GRB 240529A: Skynet Optical Observations
  7. LXT 240528A: LEIA detection of a fast X-ray transient
  8. GRB 240529A: Swift-BAT refined analysis
  9. LIGO/Virgo S240527fv: GRANDMA/FRAM-Auger Optical Observations
  10. GRB 240529A: Swift-XRT refined Analysis
  11. GRB240529A: BOOTES-6/DPRT optical detection
  12. GRB 240529A: Swift/UVOT Detection
  13. GRB 240529A: NOT optical observations
  14. GRB 240529A: AstroSat CZTI detection
  15. GRB 240529A: GOTO optical afterglow detection
  16. GRB 240527B: Swift-XRT afterglow detection
  17. GRB 240529A: Enhanced Swift-XRT position
  18. GRB 240529A: Swift detection of a burst with an optical counterpart
  19. Swift GRB240529.12: Global MASTER-Net observations report
  20. LIGO/Virgo/KAGRA S240527fv: Updated Sky localization
  21. GRB 240527B: Fermi GBM Observation
  22. Fermi GRB 240527A: Global MASTER-Net observations report
  23. LIGO/Virgo/KAGRA S240527fv: Identification of a GW compact binary merger candidate
  24. GRB 240527B: Fermi-LAT detection
  25. LAT GRB240527.59: Global MASTER-Net observations report
  26. LIGO/Virgo/KAGRA S240527en: Identification of a GW compact binary merger candidate
  27. Fermi GRB 240527B: Global MASTER-Net observations report
  28. GRB 240527B: Fermi GBM Final Localization
  29. GRB 240527B: BALROG localization (Fermi Trigger 738511436 / GRB 240527586)
  30. GRB 240527A: Fermi GBM Final Real-time Localization
  31. GRB 240523A: Swift-BAT refined analysis
  32. Fermi trigger No 738348224: Global MASTER-Net observations report
  33. Fermi trigger No 738330463: Global MASTER-Net observations report
  34. LIGO/Virgo/KAGRA S240525p: Updated Sky localization
  35. LIGO/Virgo/KAGRA S240525p: Identification of a GW compact binary merger candidate
  36. GRB 240523A: Swift-XRT refined Analysis
  37. GRB 240523A: Enhanced Swift-XRT position
  38. GRB 240523A: Swift detection of a burst
  39. GRB 240521B: Fermi GBM Observation
  40. Fermi GBM Sub-Threshold Detection of GRB 240516B
  41. GRB 240513A: Swift-XRT afterglow detection
  42. GRB 240521B: Swift/BAT-GUANO arcminute localization of a long burst
  43. Fermi trigger No 737996942: Global MASTER-Net observations report
  44. LIGO/Virgo/KAGRA S240520cv: Updated Sky localization and EM Bright Classification
  45. EP240518a: GSP optical upper limit
  46. GRB 240521A: GECAM-B detection of a long burst
  47. GRB 240516B: AstroSat CZTI detection
  48. LIGO/Virgo/KAGRA S240515m: Upper limits from Swift/BAT-GUANO
  49. LIGO/Virgo/KAGRA S240514x: Upper limits from Swift/BAT-GUANO
  50. LIGO/Virgo/KAGRA S240513ei: Upper limits from Swift/BAT-GUANO
  51. LIGO/Virgo/KAGRA S240520cv: Identification of a GW compact binary merger candidate
  52. IceCube-Cascade 240518A: Upper limits from a search for additional neutrino events in IceCube
  53. GRB 240514B: VZLUSAT-2 detection
  54. GRB 240504A: VZLUSAT-2 detection
  55. GRB 240502A: VZLUSAT-2 detection
  56. GRB 240519A: GRBAlpha detection
  57. GRB 240516A: Swift/UVOT Upper Limits
  58. GRB 240519A: AstroSat CZTI detection
  59. Fermi trigger No 737788024: Global MASTER-Net observations report
  60. EP240518a: possibly identified with a flare star by EP-FXT
  61. GRB 240519A: BALROG localization (Fermi Trigger 737788024 / GRB 240519213)
  62. EP240518a: EP-WXT detection of a new X-ray transient
  63. LIGO/Virgo/KAGRA S240514c: Updated Sky localization
  64. GRB 240516A: Swift-BAT refined analysis
  65. Fermi GRB 240517A: Global MASTER-Net observations report
  66. GRB 240516A ATCA radio observations
  67. IPN triangulation of GRB 240514B (short)
  68. GRB 240513A: Swift ToO observations
  69. GRB 240517A: Fermi GBM Final Real-time Localization
  70. Konus-Wind detection of GRB 240513A
  71. GRB 240516A: AstroSat CZTI detection
  72. GRB 240516A: Swift-XRT refined Analysis
  73. GRB 240514E: A possible candidate BD-21 1074
  74. Fermi trigger No 737559855: Global MASTER-Net observations report
  75. GRB 240516A: Fermi GBM Observation
  76. GRB 240511A: Observations from GTC/OSIRIS+
  77. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  78. GRB 240516A: GOTO optical upper limit
  79. LIGO/Virgo/KAGRA S240422ed: GRID non-detection and upper limits
  80. Fermi trigger No 737523389: Global MASTER-Net observations report
  81. GRB 240516A: Swift detection of a burst
  82. Swift GRB240516.15: Global MASTER-Net observations report
  83. GRB 240514B: AT2024ixa/GOTO24bph is not consistent with the Fermi localisation
  84. Fermi trigger No 737476171: Global MASTER-Net observations report
  85. GRB 240511A: radio detection of afterglow candidate
  86. GRB 240514B: GOTO candidate optical counterpart
  87. MAXI GRB240514.78: Global MASTER-Net observations report
  88. Fermi Gamma-ray Burst Monitor list of triggers that are not a GRB
  89. GRB 240514E: MAXI/GSC detection of a probable afterglow
  90. GRB 240514B: GRBAlpha detection
  91. LIGO/Virgo/KAGRA S240514x: Updated Sky localization
  92. LIGO/Virgo/KAGRA S240515m: Identification of a GW compact binary merger candidate
  93. GRB 240514B: Fermi GBM Detection
  94. LIGO/Virgo/KAGRA S240422ed: Las Cumbres Observatory Follow-up Observations of the Localization Region
  95. GRB 240513A: Fermi GBM observation
  96. GRB 240513A: Swift-XRT observations
  97. LIGO/Virgo/KAGRA S240513ei: Updated Sky localization
  98. LIGO/Virgo/KAGRA S240514x: Identification of a GW compact binary merger candidate
  99. GRB 240514D: AstroSat CZTI detection
  100. GRB 240514C: Fermi GBM Final Real-time Localization

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