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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"

27279 results found.

  1. Fermi trigger No 737523389: Global MASTER-Net observations report
  2. GRB 240516A: Swift detection of a burst
  3. Swift GRB240516.15: Global MASTER-Net observations report
  4. Fermi trigger No 737476171: Global MASTER-Net observations report
  5. GRB 240514B: GOTO candidate optical counterpart
  6. MAXI GRB240514.78: Global MASTER-Net observations report
  7. Fermi Gamma-ray Burst Monitor list of triggers that are not a GRB
  8. GRB 240514B: Fermi GBM Detection
  9. GRB 240513A: Fermi GBM observation
  10. GRB 240514C: Fermi GBM Final Real-time Localization
  11. Fermi GRB 240514B: Global MASTER-Net observations report
  12. Fermi Gamma-ray Burst Monitor triggers 737345659/240514093 and GRB240514A are not GRBs
  13. GRB 240514B: Fermi GBM Final Real-time Localization
  14. LIGO/Virgo/KAGRA S240507p: Upper limits from Swift/BAT-GUANO
  15. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  16. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  17. GRB 240514A: Fermi GBM Final Real-time Localization
  18. LAT GRB240513.31: Global MASTER-Net observations report
  19. GRB 240513A: Fermi-LAT detection
  20. GRB 240511A: Fermi GBM Observation
  21. GRB 240511A: Swift-BAT refined analysis
  22. Fermi GRB 240513B: Global MASTER-Net observations report
  23. Fermi trigger No 737277727: Global MASTER-Net observations report
  24. GRB 240513B: Fermi GBM Final Real-time Localization
  25. GRB 240513A: AstroSat CZTI detection
  26. LIGO/Virgo/KAGRA S240513cx: Coverage and upper limits from MAXI/GSC observations
  27. Fermi trigger No 737258655: Global MASTER-Net observations report
  28. Fermi trigger No 737247400: Global MASTER-Net observations report
  29. Fermi trigger No 737244199: Global MASTER-Net observations report
  30. Fermi trigger No 737218721: Global MASTER-Net observations report
  31. Fermi trigger No 737196587: Global MASTER-Net observations report
  32. Fermi trigger No 737168073: Global MASTER-Net observations report
  33. GRB 240511A : MITSuME Akeno optical upper limits
  34. GRB 240511A: Swift-XRT refined Analysis
  35. GRB 240511A: optical afterglow detection from the NOT
  36. Fermi Gamma-ray Burst Monitor trigger 737102480/240511279 is not a GRB
  37. Fermi Gamma-ray Burst Monitor trigger 737111207/240511380 is not a GRB
  38. Fermi GBM trigger 737105243/240511311 is not a GRB
  39. Fermi trigger No 737173236: Global MASTER-Net observations report
  40. Fermi GRB 240511A: Global MASTER-Net observations report
  41. Swift GRB 240511A: Global MASTER-Net observations report
  42. Fermi trigger No 737105243: Global MASTER-Net observations report
  43. Fermi Gamma-ray Burst Monitor trigger 737133200/240511634 is not a GRB
  44. Fermi trigger No 737152719: Global MASTER-Net observations report
  45. GRB 240511A: Swift detection of a burst
  46. GRB 240511A: Fermi GBM Final Real-time Localization
  47. Fermi trigger No 737102480: Global MASTER-Net observations report
  48. Fermi trigger No 737111207: Global MASTER-Net observations report
  49. Fermi Gamma-ray Burst Monitor trigger 737076431/240510977 is not a GRB
  50. Fermi trigger No 736967879: Global MASTER-Net observations report
  51. EP240506a: Xinglong optical upper limit
  52. Fermi Gamma-ray Burst Monitor trigger 230925241/717313591 is not a GRB
  53. EP240506a: CrAO ZTSH optical upper limit
  54. GRB 240504A: Fermi GBM Observation
  55. Fermi Gamma-ray Burst Monitor trigger 736837160/240508208 is not a GRB
  56. EP240506a: TRT optical upper limit
  57. EP240506a: BOOTES Network optical upper limit
  58. Fermi trigger No 736733320: Global MASTER-Net observations report
  59. EP240506a: Optical upper limit with Kinder observations
  60. IPN triangulation of GRB 240504A
  61. EP240506a: EP-WXT detection of a new fast X-ray transient
  62. LIGO/Virgo/KAGRA S240422ed: Additional WINTER near-infrared J-band observations
  63. GRB 240504A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  64. Fermi GBM triggers 736668287/240506253 and 736669277/240506265 are not GRBs
  65. Fermi trigger No 736564880: Global MASTER-Net observations report
  66. Fermi trigger No 736461232: Global MASTER-Net observations report
  67. Fermi GRB 240504A: Global MASTER-Net observations report
  68. Fermi trigger No 736472503: Global MASTER-Net observations report
  69. GRB 240504A: BALROG localization (Fermi Trigger 736492377 / GRB 240504217)
  70. GRB 240504A: Fermi GBM Final Real-time Localization
  71. Fermi trigger No 736387941: Global MASTER-Net observations report
  72. LXT 240402A / GRB 240402B: VLT X-shooter redshift of host
  73. GRB 240502A: GOTO optical upper limit
  74. Fermi trigger No 736379109: Global MASTER-Net observations report
  75. GRB 240502A: Fermi GBM Observation
  76. GRB 240502C: GOTO possible optical counterpart candidates
  77. Fermi GRB 240502B: Global MASTER-Net observations report
  78. GRB 240502C: Fermi GBM Final Localization
  79. Fermi GRB 240502A: Global MASTER-Net observations report
  80. GRB 240430A: GRBAlpha detection
  81. GRB 240502B: Fermi GBM Final Real-time Localization
  82. LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet Transient Candidates
  83. Integral GRB240502.23: Global MASTER-Net observations report
  84. GRB 240502A: Fermi GBM Final Real-time Localization
  85. Fermi GRB 240501A: Global MASTER-Net observations report
  86. Fermi trigger No 736197684: Global MASTER-Net observations report
  87. GRB 240426A: VZLUSAT-2 detection
  88. GRB240430A: Fermi GBM Final Localization
  89. GRB 240501A: Fermi GBM Final Real-time Localization
  90. GRB 240408B: VZLUSAT-2 detection
  91. GRB 240407A: VZLUSAT-2 detection
  92. GRB 240429A: Fermi GBM Final Real-time Localization
  93. LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet ToO observations
  94. LIGO/Virgo/KAGRA S240429an: Retraction of GW compact binary merger candidate
  95. Fermi GRB 240428A: Global MASTER-Net observations report
  96. GRB 240428A: Fermi GBM Final Real-time Localization
  97. EP240426b: EP-WXT detection of a new fast X-ray transient
  98. LIGO/Virgo/KAGRA S240422ed: EP-FXT Detection of the Potential Opitcal Electromagnetic Counterpart AT 2024hfq Reported by DECam
  99. LIGO/Virgo/KAGRA S240422ed: EP-FXT detection of a candidate counterpart EP240426a
  100. LIGO/Virgo/KAGRA S240422ed: Zwicky Transient Facility contuinued observations of S240422ed and candidate analysis

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