Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

22056 results found.

  1. IceCube Alert 230122.16: Global MASTER-Net observations report
  2. Fermi GRB 230118A: Global MASTER-Net observations report
  3. GRB 230116D: SAO RAS further observations
  4. GRB 230116D: SAO RAS photometry
  5. GRB 230116D: KGO RC-25 optical observations
  6. GRB 230116D: Sintez-Newton/CrAO optical observations
  7. GRB 230116D: SAO RAS redshift
  8. Fermi trigger No 695569700: Global MASTER-Net observations report
  9. Fermi GRB 230117A: Global MASTER-Net observations report
  10. GRB 230116D: SAO RAS observations of OT brightening
  11. GRB 230116D: Nanshan/NEXT optical afterglow detection
  12. Swift GRB230116.88: Global MASTER-Net observations report
  13. IceCube-230112A: No Candidate Counterparts from the Zwicky Transient Facility
  14. GRB 230116C: Swift detection of a burst
  15. Fermi-LAT gamma-ray observations of IceCube-230112A
  16. Fermi-LAT Gamma-ray Observations of IceCube-Cascade-230109A
  17. Fermi-LAT Gamma-ray Observations of IceCube-Cascade-221229A
  18. Fermi GRB 230112A: Global MASTER-Net observations report
  19. IceCube Alert 230112.28: Global MASTER-Net observations report
  20. Fermi trigger No 695057654: Global MASTER-Net observations report
  21. IceCube-221223A: JCMT/SCUBA2 observations
  22. GRB 230102A: Swift/BAT-GUANO detection outside the coded FOV
  23. GRB 230102A: Detection by GRBAlpha
  24. Fermi trigger No 694259491: Global MASTER-Net observations report
  25. GRB 221231A: Swift-XRT afterglow detection
  26. GRB 221231A: AKO Upper Limit
  27. GRB 221231A: Swift-XRT observations
  28. IceCube-221223A: No Candidate Counterparts from the Zwicky Transient Facility
  29. GRB 221231A: Swift ToO observations
  30. GRB 221231A: Swift/BAT-GUANO arcminute localization of a possibly short burst
  31. Fermi trigger No 694232203: Global MASTER-Net observations report
  32. Fermi-LAT gamma-ray observations of IceCube-221229A
  33. GRB 221226A: Swift/BAT-GUANO detection outside the coded FOV
  34. ZTF22acaruqr/AT2022adzb: Neil Gehrels Swift Observatory X-ray detection
  35. GRB 221226B: Swift-UVOT Detection
  36. GRB 221226B: VLT/X-shooter redshift and host galaxy
  37. Swift GRB221226.95: Global MASTER-Net observations report
  38. Fermi GRB 221226A: Global MASTER-Net observations report
  39. Fermi-LAT gamma-ray observations of IceCube-221224A
  40. IceCube-221223A: BOOTES-4/MET Optical Observations
  41. Fermi-LAT gamma-ray observations of IceCube-221223A
  42. Fermi GRB 221223A: Global MASTER-Net observations report
  43. IceCube Alert 221224.04: Global MASTER-Net observations report
  44. IceCube Alert 221223.32: Global MASTER-Net observations report
  45. Fermi GRB 221221A: Global MASTER-Net observations report
  46. GRB 221218A: 3.6m DOT optical upper limit
  47. IceCube-221216A: No Candidate Counterparts from the Zwicky Transient Facility
  48. IceCube-221210A: BOOTES-4/MET and Lijiang 2.4-meter Telescopes Optical Observations
  49. Integral GRB221218.34: Global MASTER-Net observations report
  50. Fermi-LAT gamma-ray observations of IceCube-221216A
  51. GRB 221216A: Swift/UVOT Upper Limits
  52. Fermi-LAT gamma-ray observations of IceCube-221210A
  53. IceCube Alert 221216.25: Global MASTER-Net observations report
  54. GRB 221215A: Swift-XRT observations
  55. Swift GRB 221216A: Global MASTER-Net observations report
  56. GRB 221216A: Zadko observatory - Gingin optical observations
  57. Fermi trigger No 692760884: Global MASTER-Net observations report
  58. GRB 221215A: Swift ToO observations
  59. GRB 221215A: Swift/BAT-GUANO arcminute localization
  60. Konus-Wind detection of GRB 221209A
  61. Fermi GRB 221215B: Global MASTER-Net observations report
  62. Swift GRB221215.15: Global MASTER-Net observations report
  63. Fermi trigger No 692713692: Global MASTER-Net observations report
  64. Fermi trigger No 692607435: Global MASTER-Net observations report
  65. Fermi GRB 221211A: Global MASTER-Net observations report
  66. IceCube Alert 221210.36: Global MASTER-Net observations report
  67. GRB 221009A: MuSCAT3 observations
  68. GRB 221206B: Swift-XRT observations
  69. GRB 221206B: Detection by GRBAlpha
  70. GRB 221206B: Swift/BAT-GUANO candidate arcminute localization
  71. GRB 221206B: Swift ToO observations
  72. Swift GRB221204.45: Global MASTER-Net observations report
  73. GRB 221202A: Swift/UVOT Detection
  74. GRB 221202A: VLT/FORS2 Afterglow Discovery
  75. GRB 221202A: MeerLICHT upper limits
  76. Swift GRB221202.84: Global MASTER-Net observations report
  77. GCN: GRB 221201A: Swift/UVOT Upper Limits
  78. Swift GRB 221201A: Global MASTER-Net observations report
  79. Konus-Wind detection of GRB 221124A
  80. Optical polarization observation of GRB 221009A
  81. GRB 221127A: Detection by GRBAlpha
  82. Alert from the HAWC Burst Monitor HAWC-221128A
  83. GRB 221126A: Swift/BAT-GUANO detection outside the coded FOV
  84. GRB 221124A: Swift/BAT-GUANO detection
  85. Fermi-LAT gamma-ray observations of IceCube-221124A
  86. IceCube Alert 221124.66: Global MASTER-Net observations report
  87. Alert from the HAWC Burst Monitor HAWC-221123A
  88. GRB 221120A: GTC Confirmation of an Underlying Galaxy
  89. GRB221120A: WIRC near-IR imaging of the afterglow candidate
  90. GRB 221120A: Liverpool Telescope Upper Limits
  91. GRB 221120A: Archival PS1 Imaging of Faint Source near XRT position
  92. GRB221120A: Montarrenti Observatory Upper Limit
  93. GRB 221120A: Swift/UVOT Upper Limits
  94. GRB 221120A: LDT Optical Afterglow Candidate
  95. GRB 221120A: GIT upper limits on optical afterglow
  96. LAT GRB221119.63: Global MASTER-Net observations report
  97. GRB 221009A: Japanese VLBI Network observation
  98. Correction to GCN 32646 (GRB 221009A (Swift J1913.1+1946): MeerLICHT observations)
  99. GRB 221115B : MeerLICHT upper limits
  100. GRB 221115B: Swift/BAT-GUANO arcminute localization

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov