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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"

21109 results found.

  1. GRB 230116D: SAO RAS further observations
  2. GRB 230116D: SAO RAS photometry
  3. GRB 230116D: KGO RC-25 optical observations
  4. GRB 230116D: Sintez-Newton/CrAO optical observations
  5. GRB 230116D: SAO RAS redshift
  6. Fermi trigger No 695569700: Global MASTER-Net observations report
  7. Fermi GRB 230117A: Global MASTER-Net observations report
  8. GRB 230116D: SAO RAS observations of OT brightening
  9. GRB 230116D: Nanshan/NEXT optical afterglow detection
  10. Swift GRB230116.88: Global MASTER-Net observations report
  11. IceCube-230112A: No Candidate Counterparts from the Zwicky Transient Facility
  12. Fermi-LAT gamma-ray observations of IceCube-230112A
  13. Fermi-LAT Gamma-ray Observations of IceCube-Cascade-230109A
  14. Fermi-LAT Gamma-ray Observations of IceCube-Cascade-221229A
  15. Fermi GRB 230112A: Global MASTER-Net observations report
  16. IceCube Alert 230112.28: Global MASTER-Net observations report
  17. Fermi trigger No 695057654: Global MASTER-Net observations report
  18. IceCube-221223A: JCMT/SCUBA2 observations
  19. GRB 230102A: Detection by GRBAlpha
  20. Fermi trigger No 694259491: Global MASTER-Net observations report
  21. GRB 221231A: Swift-XRT afterglow detection
  22. GRB 221231A: AKO Upper Limit
  23. GRB 221231A: Swift-XRT observations
  24. IceCube-221223A: No Candidate Counterparts from the Zwicky Transient Facility
  25. GRB 221231A: Swift ToO observations
  26. GRB 221231A: Swift/BAT-GUANO arcminute localization of a possibly short burst
  27. Fermi trigger No 694232203: Global MASTER-Net observations report
  28. Fermi-LAT gamma-ray observations of IceCube-221229A
  29. ZTF22acaruqr/AT2022adzb: Neil Gehrels Swift Observatory X-ray detection
  30. GRB 221226B: Swift-UVOT Detection
  31. GRB 221226B: VLT/X-shooter redshift and host galaxy
  32. Swift GRB221226.95: Global MASTER-Net observations report
  33. Fermi GRB 221226A: Global MASTER-Net observations report
  34. Fermi-LAT gamma-ray observations of IceCube-221224A
  35. IceCube-221223A: BOOTES-4/MET Optical Observations
  36. Fermi-LAT gamma-ray observations of IceCube-221223A
  37. Fermi GRB 221223A: Global MASTER-Net observations report
  38. IceCube Alert 221224.04: Global MASTER-Net observations report
  39. IceCube Alert 221223.32: Global MASTER-Net observations report
  40. Fermi GRB 221221A: Global MASTER-Net observations report
  41. GRB 221218A: 3.6m DOT optical upper limit
  42. IceCube-221216A: No Candidate Counterparts from the Zwicky Transient Facility
  43. IceCube-221210A: BOOTES-4/MET and Lijiang 2.4-meter Telescopes Optical Observations
  44. Integral GRB221218.34: Global MASTER-Net observations report
  45. Fermi-LAT gamma-ray observations of IceCube-221216A
  46. GRB 221216A: Swift/UVOT Upper Limits
  47. Fermi-LAT gamma-ray observations of IceCube-221210A
  48. IceCube Alert 221216.25: Global MASTER-Net observations report
  49. GRB 221215A: Swift-XRT observations
  50. Swift GRB 221216A: Global MASTER-Net observations report
  51. GRB 221216A: Zadko observatory - Gingin optical observations
  52. Fermi trigger No 692760884: Global MASTER-Net observations report
  53. GRB 221215A: Swift ToO observations
  54. GRB 221215A: Swift/BAT-GUANO arcminute localization
  55. Fermi GRB 221215B: Global MASTER-Net observations report
  56. Swift GRB221215.15: Global MASTER-Net observations report
  57. Fermi trigger No 692713692: Global MASTER-Net observations report
  58. Fermi trigger No 692607435: Global MASTER-Net observations report
  59. Fermi GRB 221211A: Global MASTER-Net observations report
  60. IceCube Alert 221210.36: Global MASTER-Net observations report
  61. GRB 221009A: MuSCAT3 observations
  62. GRB 221206B: Swift-XRT observations
  63. GRB 221206B: Detection by GRBAlpha
  64. GRB 221206B: Swift/BAT-GUANO candidate arcminute localization
  65. GRB 221206B: Swift ToO observations
  66. Swift GRB221204.45: Global MASTER-Net observations report
  67. GRB 221202A: Swift/UVOT Detection
  68. GRB 221202A: VLT/FORS2 Afterglow Discovery
  69. GRB 221202A: MeerLICHT upper limits
  70. Swift GRB221202.84: Global MASTER-Net observations report
  71. GCN: GRB 221201A: Swift/UVOT Upper Limits
  72. Swift GRB 221201A: Global MASTER-Net observations report
  73. Optical polarization observation of GRB 221009A
  74. GRB 221127A: Detection by GRBAlpha
  75. Alert from the HAWC Burst Monitor HAWC-221128A
  76. Fermi-LAT gamma-ray observations of IceCube-221124A
  77. IceCube Alert 221124.66: Global MASTER-Net observations report
  78. Alert from the HAWC Burst Monitor HAWC-221123A
  79. GRB 221120A: GTC Confirmation of an Underlying Galaxy
  80. GRB221120A: WIRC near-IR imaging of the afterglow candidate
  81. GRB 221120A: Liverpool Telescope Upper Limits
  82. GRB221120A: Montarrenti Observatory Upper Limit
  83. GRB 221120A: Swift/UVOT Upper Limits
  84. GRB 221120A: LDT Optical Afterglow Candidate
  85. GRB 221120A: GIT upper limits on optical afterglow
  86. LAT GRB221119.63: Global MASTER-Net observations report
  87. GRB 221009A: Japanese VLBI Network observation
  88. Correction to GCN 32646 (GRB 221009A (Swift J1913.1+1946): MeerLICHT observations)
  89. GRB 221115B : MeerLICHT upper limits
  90. GRB 221110A: GRANDMA observations
  91. GRB 221110A: COATLI Second-Epoch Upper Limits
  92. GRB 221009A: GRANDMA/Kilonova-Catcher observations
  93. GRB 221110A: Swift/UVOT Detection and Corrected UVOT Position
  94. GRB 221110A: COATLI Afterglow detection
  95. Swift GRB221110.10: Global MASTER-Net observations report
  96. Fermi-GBM Observations of High Bursting Activity from SGR J1935+2154
  97. GRB 221009A: Hubble Space Telescope observations
  98. Correction to GCN 32852 (GRB 221009A: SARA-RM 1m Optical Afterglow Detection)
  99. IceCube Alert 221104.26: Global MASTER-Net observations report
  100. Fermi-LAT gamma-ray observations of IceCube-221104A

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