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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"

36214 results found.

  1. GRB 230616A: Swift-XRT observations
  2. GRB 230618A: KAIT Optical Observations
  3. Swift GRB 230618A: Global MASTER-Net observations report
  4. GRB230618A: LCOGT Optical Observations
  5. GRB 230618B: Fermi GBM Final Real-time Localization
  6. GRB 230618A: Prompt enhanced Swift-XRT position
  7. GRB 230618A: Swift detection of a burst
  8. GRB 230616A: Swift ToO observations
  9. GRB 230617A: Fermi GBM Final Real-time Localization
  10. GRB 230614C: GRBAlpha detection
  11. GRB 230616A: AstroSat CZTI detection
  12. GRB 230616A: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  13. GRB 230614C: AstroSat CZTI detection
  14. GRB 230614B: Fermi GBM Observation
  15. GRB 230614C: Fermi GBM Detection
  16. GRB 230614B: Swift/BAT-GUANO detection outside the coded FOV
  17. GRB 230614B: Fermi GBM Final Real-time Localization
  18. GRB 230614A: Fermi GBM Final Real-time Localization
  19. GRB 230606A: LCOGT Optical Observations
  20. GRB 230608A: CALET Gamma-Ray Burst Monitor detection
  21. GRB 230608A: AstroSat CZTI detection
  22. GRB 230608A: AGILE detection
  23. Fermi GRB 230603A: Global MASTER-Net observations report
  24. GRB 230506B: Chandra localization of the X-ray afterglow
  25. GRB 230606A: Swift-BAT refined analysis
  26. GRB 230606A: Gaoyazi/GOT optical upper limit
  27. GRB 230606A: Fermi GBM Observation
  28. GRB 230606A: BOOTES-5/JGT optical upper limit
  29. GRB 230606A: Swift-XRT refined Analysis
  30. GRB 230604A: GRBAlpha detection
  31. GRB 230606A: Swift/UVOT Upper Limits
  32. GRB 230606A: Enhanced Swift-XRT position
  33. GRB 230606A: Swift detection of a burst
  34. IceCube-230603A: Upper limits from a search for additional neutrino events in IceCube
  35. GRB 230604A: AstroSat CZTI detection of a short GRB
  36. GRB 230603A: Fermi GBM Final Real-time Localization
  37. GRB 230521A: VZLUSAT-2 detection
  38. GRB 230522A: GRBAlpha and VZLUSAT-2 joint detection
  39. GRB 230525A: CALET Gamma-Ray Burst Monitor detection
  40. LIGO/Virgo/KAGRA S230529ay: Upper limits from Fermi-GBM Observations
  41. LIGO/Virgo/KAGRA S230529ay: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  42. GRB 230529A: Fermi GBM Final Real-time Localization
  43. LIGO/Virgo/KAGRA S230518h: Upper limits from Glowbug gamma-ray observations
  44. GRB 230510A: Swift-BAT refined analysis
  45. GRB 230525A: Fermi GBM Detection
  46. GRB 230525A: Fermi GBM Final Localization
  47. GRB 230523B: GRBAlpha detection
  48. GRB 230524A: Fermi GBM Observation
  49. GRB 230524B: AstroSat CZTI detection
  50. GRB 230524A: AstroSat CZTI detection
  51. GRB 230524A: AGILE detection
  52. GRB 230524A: Fermi GBM Final Real-time Localization
  53. GRB 230523B: Name correction from GCN Circular 33859
  54. GRB 230523A: Swift/BAT-GUANO detection of a short hard burst
  55. Fermi Gamma-ray Burst Monitor trigger 706536788/230523509 is not a GRB
  56. GRB 230523A: Fermi GBM Final Real-time Localization
  57. GRB 230518B: VZLUSAT-2 detection
  58. Fermi Gamma-ray Burst Monitor trigger 706338208/230521211 is not a GRB
  59. IPN triangulation of GRB 230518A (short)
  60. GRB 230520A: CALET Gamma-Ray Burst Monitor detection
  61. GRB 230521A: Fermi GBM Final Real-time Localization
  62. GRB 230520B is not a GRB
  63. GRB 230520B: Fermi GBM Final Real-time Localization
  64. GRB 230520A: MAXI/GSC detection
  65. GRB 230518A: Fermi GBM Observation
  66. LIGO/Virgo/KAGRA S230518h: Upper limits from Konus-Wind observations
  67. GRB 230518A: Swift/BAT-GUANO detection
  68. GRB 230518A: Fermi GBM Final Real-time Localization
  69. Fermi Gamma-ray Burst Monitor trigger 706068974/230518095 is not a GRB
  70. LIGO/Virgo/KAGRA S230518h: Upper limits from Fermi-GBM Observations
  71. LIGO/Virgo S230518h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  72. GRB 230513A: Zwicky Transient Facility continuous observations of a Fermi Short GRB (Trigger 705709044)
  73. GRB 230510B: GRBAlpha detection
  74. GRB 230517A: BALROG localization (Fermi Trigger 706014351 / GRB 230517462)
  75. Improved IPN triangulation of GRB 230512A
  76. GRB 230517A: Fermi GBM Final Real-time Localization
  77. GRB 230510B: Fermi GBM detection
  78. GRB 230516A: Fermi GBM Final Real-time Localization
  79. IPN triangulation of GRB 230511D (short)
  80. IPN triangulation of GRB 230512A
  81. GRB 230513A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
  82. GRB 230512A: Nanshan/NEXT non-detection of GRB afterglow candidate
  83. GRB 230512A: Zwicky Transient Facility non-detection of GRB afterglow candidate
  84. GRB 230512A: Liverpool Telescope observations
  85. GRB 230512A: GIT non detection of afterglow candidate
  86. GRB 230512A: Kitab possible afterglow candidate
  87. GRB 230512A: GRBAlpha detection
  88. GRB 230510A: GRBAlpha detection
  89. GRB 230513A: Fermi GBM Final Real-time Localization
  90. GRB 230510A: OHP/T193 and OHP/T120 optical observations
  91. GRB 230512A: Swift-XRT observations
  92. IceCube-230511A: Upper limits from a search for additional neutrino events in IceCube
  93. GRB 230512A: GIT optical follow-up ZTF candidates
  94. GRB 230512A: Fermi GBM detection
  95. GRB 230512A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705565670)
  96. GRB 230430A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 704533643)
  97. GRB 230511D: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705537623)
  98. GRB 230512A: Tiled Swift observations
  99. GRB 230512A: Fermi-LAT detection
  100. GRB 230512A: AstroSat CZTI detection

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