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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"

28108 results found.

  1. GRB 211023B: LBT likely spectroscopic redshift of the host galaxy
  2. Alert from the HAWC Burst Monitor HAWC-211123A
  3. GRB 211120A: AstroSat CZTI detection
  4. Fermi trigger No 659106591: Global MASTER-Net observations report
  5. GRB 211120B: Swift/BAT-GUANO detection outside the coded FOV
  6. GRB 211120A: GECAM detection
  7. GRB 211118A: AstroSat CZTI detection
  8. GRB 211023A: optical observations and photometric evidence of supernova
  9. Fermi-LAT Gamma-ray Observations of IceCube-211117A
  10. GRB211118A: Swift/BAT-GUANO detection outside the coded FOV
  11. Search for counterpart to IceCube-211117A with ANTARES
  12. IceCube-211116A: Upper limits from a search for additional neutrino events in IceCube
  13. Fermi-LAT Gamma-ray Observations of IceCube-211116A
  14. IceCube-211116A: No neutrino counterpart detected with ANTARES
  15. Konus-Wind detection of GRB 211107B
  16. GRB 211115A: MAXI/GSC detection
  17. GRB 211023A: classification and SPI-ACS/INTEGRAL registration
  18. GRB 211106A: Swift/UVOT upper limits
  19. GRB 211110A: AstroSat CZTI detection
  20. Short GRB 211106A: spectroscopy of galaxies in the field
  21. GRB 211110A: GECAM detection
  22. GRB 211107B: Swift-XRT afterglow detection
  23. GRB 211106A, GROND observations
  24. GRB 211106A: Swift-XRT afterglow detection
  25. Fermi GRB 211109B: Global MASTER-Net observations report
  26. GRB 211023A: SAO RAS optical observations
  27. GRB 211107B: Swift-XRT observations
  28. MeerLICHT follow-up of GRB 211106A
  29. GRB 211109C: GECAM detection
  30. Fermi GBM Sub-Threshold Detection of GRB 211106A
  31. GRB 211106A: Swift-XRT observations
  32. GRB 211106A: Swift/BAT-GUANO candidate arcminute localization of a short burst
  33. GRB 211105A: MASTER optical inspection
  34. GRB 211105A: Swift/BAT-GUANO detection outside the coded FOV
  35. GRB 211105A: GECAM detection
  36. Swift Trigger 1082569 is probably not a GRB
  37. GRB 211023A: optical detection by SBT in Ondrejov
  38. GRB 211023B: Subaru optical observation
  39. GRB 211024A: MITSuME Akeno optical observation
  40. GRB 211102B: GECAM detection
  41. GRB 211102B: BALROG localization (Fermi Trigger 657554740 / GRB 211102587)
  42. GRB 211023B: MITSuME Akeno optical upper limits
  43. GRB 211102A: BALROG localization (Fermi Trigger 657533168 / GRB 211102338)
  44. GRB 211024B: Optical afterglow observation by Ondrejov D50
  45. GRB 211024A: 1.3m DFOT observations
  46. IPN triangulation of GRB 211022A
  47. GRB 2121023B: 6 GHz VLA radio upper limit
  48. AMON NuEm-211020A: No Candidate Counterparts from Swift-XRT follow up observations
  49. GRB 211024A: Swift-XRT source 4 is not an afterglow.
  50. GRB 211023B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  51. GRB 211024A: Possible afterglow candidate from GIT
  52. GRB 211024A: Swift-XRT observations
  53. GRB 211018A: Swift-XRT observations
  54. GRB 211025A: Optical Afterglow Detection
  55. GRB211023A: optical afterglow detection from Konkoly Observatory
  56. GRB 211024A: Swift/BAT-GUANO detection and candidate arcminute localization of a short burst
  57. GRB 211023B: Mondy optical afterglow confirmation
  58. GRB 211023B: LDT Optical Afterglow Detection
  59. IceCube-211023A: Upper limits from a search for additional neutrino events in IceCube
  60. GRB 211025A: Swift-BAT refined analysis
  61. GRB 211025A: Swift-XRT refined Analysis
  62. GRB 211024B: Swift-XRT refined Analysis
  63. GRB 211025A: Swift/UVOT Detection
  64. GRB 211024B: Swift-BAT refined analysis
  65. GRB 211025A: Enhanced Swift-XRT position
  66. GRB 211025A: Swift detection of a burst
  67. GECAM detection of a short burst probably from SGR J1555.2-5402
  68. GRB 211024B: Nanshan/NEXT optical afterglow detection
  69. GRB 210919A: FORS2/VLT observations
  70. GRB 211023B: Swift-BAT refined analysis
  71. Fermi-LAT Gamma-ray Observations of IceCube-211023A
  72. GRB 211023B: Swift/UVOT Detection
  73. GRB 211024A: GECAM detection
  74. GRB 211023B: RATIR Optical and NIR Upper Limits
  75. GRB 211023B: TSHAO optical observation
  76. IceCube-211023A: No neutrino counterpart detected with ANTARES
  77. GRB 211022A: AstroSat CZTI detection
  78. GRB 211023B: Swift-XRT refined Analysis
  79. GRB 211023B: Enhanced Swift-XRT position
  80. GRB 211023A: Fermi GBM detection
  81. GRB 211023B: Swift detection of a possibly short burst with an optical counterpart
  82. IPN Triangulation of GRB 210927B
  83. GRB 211022A: GECAM detection
  84. AMON IC_HAWC NuEm-211020A: No neutrino counterpart detected with ANTARES
  85. GRB 211021A: BALROG localization (Fermi Trigger 656506979 / GRB 211021460)
  86. Fermi trigger No 656506979: Global MASTER-Net observations report
  87. BepiColombo MGNS joins the IPN
  88. Fermi trigger No 656268212: Global MASTER-Net observations report
  89. GRB 211018A: Fermi GBM observation
  90. GRB 211019A: BALROG localization (Fermi Trigger 656315976 / GRB 211019250)
  91. Integral GRB211016.42: Global MASTER-Net observations report
  92. IceCube-210922A: Hard X-ray flux limit for JCMT/SCUBA2 source from NuSTAR observations
  93. Swift trigger 1078701: MITSuME Akeno optical upper limits
  94. Fermi trigger No 655673024: Global MASTER-Net observations report
  95. GRB 210919A: LDT optical observations and candidate host galaxies
  96. Swift Trigger 1078701: Mondy, CrAO, AbAO observations, possible optical counterpart
  97. Swift Trigger 1078701 is probably not a GRB
  98. IceCube-20210922A: DESNU Optical counterpart candidate from 5 nights of DECam observations
  99. GRB 211008A: BALROG localization (Fermi Trigger 655401471 / GRB 211008665)
  100. GRB 210928A: MeerKAT detection

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