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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"

27301 results found.

  1. GRB 231123A: Fermi GBM Final Real-time Localization
  2. GRB 231122B: Glowbug gamma-ray detection
  3. GRB 231117A: Continued GTC Observations
  4. Fermi trigger No 722349867: Global MASTER-Net observations report
  5. GRB 231122A: GECAM detection
  6. GRB 231122B: GECAM detection
  7. GRB 231122A: Fermi GBM Final Real-time Localization
  8. GRB 231117A: GTC Near-Infrared Observations
  9. GRB 231117A: Swift-BAT refined analysis
  10. GRB 231118A: GRBAlpha detection
  11. LIGO/Virgo/KAGRA S231118d: Upper limits from Swift/BAT-GUANO
  12. LIGO/Virgo/KAGRA S231118an: Upper limits from Swift/BAT-GUANO
  13. LIGO/Virgo/KAGRA S231114n: Upper limits from Swift/BAT-GUANO
  14. LIGO/Virgo/KAGRA S231113bb: Upper limits from Swift/BAT-GUANO
  15. GRB 231118A: VZLUSAT-2 detection
  16. GRB 231118A: Swift-BAT refined analysis
  17. GRB 231118B: CALET Gamma-Ray Burst Monitor detection
  18. GRB 231117A: CALET Gamma-Ray Burst Monitor detection
  19. 231118A: Swift-UVOT Detection
  20. GRB231117A: Swift-UVOT detection
  21. GRB 231117A : MITSuME Akeno optical afterglow candidate detection
  22. GRB 231118B: Fermi GBM observation
  23. GRB 231118A: Fermi GBM observation
  24. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
  25. GRB 231120A: Fermi GBM Final Real-time Localization
  26. GRB 231117A: Swift-XRT refined Analysis
  27. GRB 231118A: Swift-XRT refined Analysis
  28. GRB 231118A: MeerLICHT afterglow detection
  29. LIGO/Virgo/KAGRA S231119u: One counterpart neutrino candidate from IceCube neutrino searches
  30. GRB 231117A: OHP/T120 optical observations
  31. GRB 231118A: VLT/X-shooter redshift
  32. Fermi trigger No 722039659: Global MASTER-Net observations report
  33. GRB 231117A: GECAM-C detection
  34. GRB 231115A: Upper limit from CALET Gamma-Ray Burst Monitor
  35. GRB 231118A: Las Cumbres optical detection
  36. GRB 231118B: BALROG localization (Fermi Trigger 722039659 / GRB 231118940)
  37. GRB 231118B: Fermi GBM Final Real-time Localization
  38. GRB 231118A: LCOGT Optical Observations
  39. GRB 231118A: Continued Skynet Observations
  40. Swift GRB231118.72: Global MASTER-Net observations report
  41. GRB 231117A: Kinder observations with Lulin observatory for AT 2023yba without fading in r band
  42. GRB 231118A: Skynet Optical Afterglow Discovery
  43. GRB 231118A: Swift detection of a burst
  44. GRB 231118A: Fermi GBM Final Real-time Localization
  45. GRB 231117A: Lowell Discovery Telescope Observations
  46. GRB 231117A: GRBAlpha detection
  47. GRB 231117A: Keck spectroscopy of afterglow candidate
  48. GRB 231115A: JinShan optical upper limits
  49. GRB 231117A: GIT optical follow-up
  50. GRB 231117A: LT observations consistent with fading
  51. GRB 231117A: AKO Optical Upper Limit
  52. GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
  53. Swift GRB 231117A: Global MASTER-Net observations report
  54. GRB 231117A: ATLAS non-detection of an optical counterpart
  55. GRB 231115A : OHP/T120 optical upper limit
  56. GRB 231117A : MITSuME Akeno optical upper limits
  57. GRB 231117A: GOTO optical upper limits
  58. GRB 231117A: AstroSat CZTI detection of a bright short burst
  59. GRB 231117A: Swift detection of a bright short burst
  60. GRB 231115A: Non-detection of radio emission with CHIME/FRB
  61. GRB 231111A: Swift/UVOT Detection
  62. GRB 231115A: NuSTAR Follow-Up Observations
  63. GRB 231115A: Swift/BAT-GUANO detection of a short burst
  64. Fermi GRB 231116A: Global MASTER-Net observations report
  65. GRB 231115A: AGILE/MCAL upper limits
  66. GRB 231115A: Insight-HXMT/HE detection
  67. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
  68. GRB 231116A: Fermi GBM Final Real-time Localization
  69. GRB 231115A : MITSuME Akeno and Okayama optical upper limits
  70. GRB 231115A: Gaoyazi/GOT follow-up and archival observations
  71. GRB 231115A: Upper limits from a neutrino search with IceCube
  72. GRB 231115A: Kinder observations with Lulin observatory
  73. GRB231115A: GRANDMA Observations
  74. GRB 231115A: GOTO pre-burst limits of AT2023xvj
  75. GRB 231115A: pre-burst ZTF upper limits for GRB optical counterpart candidate
  76. GRB 231106A: TESS identification of candidate optical counterpart
  77. GRB 231115A: MASTER optical observations
  78. GRB 231115A: Fermi Observations of a probable Magnetar Giant Flare from M82
  79. Integral GRB231115.65: Global MASTER-Net observations report
  80. GRB 231115A: GROWTH-India discovery of a potential optical counterpart
  81. Fermi GRB 231115A: Global MASTER-Net observations report
  82. GRB 231115A: Fermi GBM Final Real-time Localization
  83. GRB 231111A: Swift-BAT refined analysis
  84. LIGO/Virgo/KAGRA S231113bw: Zwicky Transient Facility observations
  85. Fermi GRB 231114A: Global MASTER-Net observations report
  86. LIGO/Virgo/KAGRA S231113bw: GROWTH-India coverage and upper limits
  87. GECAM-B observation of a short burst from SGR J1555-5402
  88. GRB 231114A: Fermi GBM Final Localization
  89. SGRJ1555-5402: Swift/BAT-GUANO arcminute localization of a SGR flare
  90. LIGO/Virgo/KAGRA S231113bw: Upper limits from Fermi-GBM Observations
  91. GRB 231110A: CALET Gamma-Ray Burst Monitor detection
  92. LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
  93. LIGO/Virgo/KAGRA S231113bw: Coverage and upper limits from MAXI/GSC observations
  94. GRB 231110A: Swift-BAT refined analysis
  95. GRB 231111A: Xinglong-2.16m optical observations
  96. GRB 231104A: VZLUSAT-2 detection
  97. GRB 231111A NUTTelA-TAO / BSTI Early Measurements
  98. GRB 231111A: Leavitt Observatory optical observations
  99. GRB 231111A: GMG observation (correction)
  100. LIGO/Virgo/KAGRA S231112ag: Retraction of GW compact binary merger candidate

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