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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"

27304 results found.

  1. IPN triangulation of GRB 230911D (long)
  2. GRB 230911D: Fermi-LAT detection
  3. GRB230911C: LCOGT Optical Upper Limits
  4. GRB 230911C: Swift/UVOT Upper Limits
  5. Fermi trigger No 716145795: Global MASTER-Net observations report
  6. GRB 230911C: GOTO optical upper limits
  7. GRB 230908A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  8. GRB 230911D: BALROG localization (Fermi Trigger 716111594/ GRB 230911329)
  9. GRB 230911D: Fermi GBM Final Localization
  10. GRB 230911C: Swift detection of a burst
  11. Fermi GRB 230911B: Global MASTER-Net observations report
  12. GRB 230911B: Fermi GBM Final Real-time Localization
  13. GRB 230911A: Fermi GBM Final Real-time Localization
  14. GRB 230906A: BlackGEM upper limits
  15. GRB 230903A: TESS observations of optical emission
  16. GRB 230910A: Fermi GBM Final Real-time Localization
  17. GRB 230908A: GRBAlpha detection
  18. LIGO/Virgo/KAGRA S230908b: one counterpart neutrino candidate from IceCube neutrino searches
  19. GRB 230908A: AstroSat CZTI detection
  20. GRID detection of GRB 230827A
  21. GRB 230205A: LBT spectroscopy of two host galaxy candidates
  22. IPN triangulation of GRB 230906A (short)
  23. Fermi GRB 230906A: Global MASTER-Net observations report
  24. GRB 230812B: Chandra late-time detection of the X-ray afterglow
  25. GRB 230906A: Fermi GBM Final Localizationn
  26. GRB 230905B: GECAM-C detection of a long burst
  27. GRB 230905A: Fermi GBM Final Real-time Localization
  28. LIGO/Virgo/KAGRA S230819ax: Correction to PROB_BBH and PROB_TERRES probabilities
  29. GRB 230903A: Swift-XRT refined Analysis
  30. GRB 230903A: Swift-BAT refined analysis
  31. GRB 230904C: Fermi GBM Final Localization
  32. Fermi trigger No 715552087: Global MASTER-Net observations report
  33. Fermi trigger No 715429986: Global MASTER-Net observations report
  34. Fermi GRB 230903A: Global MASTER-Net observations report
  35. GRB 230903A: Fermi GBM detection
  36. GRB 230904B is not a GRB
  37. LIGO/Virgo/KAGRA S230904n: 1 counterpart neutrino candidate from IceCube neutrino searches
  38. GRB 230904B: BALROG localization (Fermi Trigger 715526984 / GRB 230904562)
  39. Fermi GRB 230904A: Global MASTER-Net observations report
  40. GRB 230904A: Fermi GBM Final Real-time Localization
  41. GRB 230903A: LCOGT Optical Upper Limits
  42. GRB 230903A: Swift detection of a burst
  43. Swift GRB230903.72: Global MASTER-Net observations report
  44. GRB 230903A: Fermi GBM Final Real-time Localization
  45. Integral GRB230902.00: Global MASTER-Net observations report
  46. GRB 230827B: Glowbug gamma-ray detection
  47. LIGO/Virgo/KAGRA S230830b: Retraction of GW compact binary merger candidate
  48. GRB 230827A: Fermi GBM Observation
  49. GRB 230827B: CALET Gamma-Ray Burst Monitor detection
  50. GRB 230826A: Swift-BAT refined analysis
  51. GRB 230828A: GRBAlpha detection
  52. Swift Trigger 1188089 is not a GRB
  53. GRB 230827A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  54. GRB 230827B: VZLUSAT-2 detection
  55. GRB 230827B / GRB 230827256: Fermi GBM Observation
  56. Subject: GRB230826A: Swift/UVOT upper limits
  57. GRB 230827A: BALROG localization (Fermi Trigger / GRB 230827762)
  58. Fermi trigger No 714809315: Global MASTER-Net observations report
  59. GRB 230827.256: AKO Optical follow-up of ZTF23abaanxz (AT 2023qxj)
  60. Fermi GRB 230827A: Global MASTER-Net observations report
  61. Swift J1727.8-1613 (GRB 230824A): Osservatorio Astronomico "Nastro Verde" optical observations
  62. GRB 230827.256 : GIT optical follow-up of ZTF23abaanxz/AT2023qxj
  63. GRB 230827A: Fermi GBM Final Real-time Localization
  64. AT 2023qxj: ZTF discovery of the likely afterglow of Fermi GRB 230827256
  65. Swift J1727.8-1613 (GRB 230824A): Montarrenti Observatory photometric observations
  66. GRB 230826A: Fermi GBM Observation
  67. Swift J1727.8-1613 (GRB 230824A): Leavitt Observatory optical observations
  68. GRB 230826A: Swift-XRT refined Analysis
  69. GRB 230826A: Mondy optical observations
  70. GRB 230826A: Swift detection of a burst
  71. GRB 230826A: Fermi GBM Final Real-time Localization
  72. Swift GRB230826.81: Global MASTER-Net observations report
  73. GRB 230818B: CALET Gamma-Ray Burst Monitor detection
  74. LIGO/Virgo/KAGRA S230825k: Upper limits from Swift/BAT-GUANO
  75. Swift GRB230825.85: Global MASTER-Net observations report
  76. Trigger 1187225: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  77. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  78. Trigger 1187207: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  79. Trigger 1187203: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  80. Swift GRB230825.75: Global MASTER-Net observations report
  81. Swift Trigger 1187199 is not an astrophysical event
  82. Fermi Gamma-ray Burst Monitor trigger 714618399/230825046 is not a GRB
  83. Trigger 1187142: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  84. Fermi trigger No 714618399: Global MASTER-Net observations report
  85. GRB 230824A: AKO Optical Afterglow Candidate
  86. Trigger 1186982: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  87. IBAS trigger 10375 is not a GRB
  88. GRB 230824A is likely a Galactic Transient: Swift J1727.8-1613
  89. Integral GRB230824.72: Global MASTER-Net observations report
  90. GRB 230824B: AstroSat CZTI detection
  91. GRB 230824A: Swift detection of a burst
  92. Swift GRB230824.58: Global MASTER-Net observations report
  93. Swift GRB230824.10: Global MASTER-Net observations report
  94. Swift Trigger 1186908 is not a GRB
  95. GRB 230822A: Fermi GBM Observation
  96. LIGO/Virgo/KAGRA S230822bm: Upper limits from Swift/BAT-GUANO
  97. GRB 230822A: Swift/BAT-GUANO detection of a burst
  98. GRID detection of GRB 230818A
  99. GRB 230822A: Fermi GBM Final Real-time Localization
  100. Swift GRB230821.64: Global MASTER-Net observations report

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