Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

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"

22214 results found.

  1. Fermi GRB 211204C: Global MASTER-Net observations report
  2. Fermi GRB 211204B: Global MASTER-Net observations report
  3. Fermi GRB 211204A: Global MASTER-Net observations report
  4. Swift GRB 211203A: Global MASTER-Net observations report
  5. Konus-Wind detection of GRB 211130A
  6. GRB 211201A: Swift/BAT-GUANO detection likely outside the coded FOV
  7. Fermi GRB 211201A: Global MASTER-Net observations report
  8. Fermi GRB 211130A: Global MASTER-Net observations report
  9. GRB 211129A: Swift/UVOT Upper Limits
  10. GRB 211106A: HST Observations
  11. GRB 211106A: Chandra Observations
  12. Swift GRB 211129A: Global MASTER-Net observations report
  13. IceCube-211125A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  14. GRB 211023A: Xinglong 2.16m optical observations
  15. GRB 211023A: Xinglong 2.16m optical observations
  16. Fermi-LAT Gamma-ray Observations of IceCube-211125A
  17. Konus-Wind detection of GRB 211120A
  18. Chandra observations of GRB 210905A
  19. IceCube Alert 211125.27: Global MASTER-Net observations report
  20. Fermi-LAT Gamma-ray Observations of IceCube-211123A
  21. IceCube-211123A: INTEGRAL was inactive at the time of the event
  22. IceCube-211123A: Upper limits from Fermi-GBM Observations
  23. IceCube-211023A: not observable by Fermi-GBM
  24. GRB 211124A: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  25. IceCube Alert 211123.60: Global MASTER-Net observations report
  26. Fermi trigger No 659413798: Global MASTER-Net observations report
  27. Trigger_21473: Tiled Swift observations
  28. GRB 211023B: LBT likely spectroscopic redshift of the host galaxy
  29. Alert from the HAWC Burst Monitor HAWC-211123A
  30. Fermi trigger No 659183098: Global MASTER-Net observations report
  31. Fermi trigger No 659106591: Global MASTER-Net observations report
  32. GRB 211120B: Swift/BAT-GUANO detection outside the coded FOV
  33. GRB 211023A: optical observations and photometric evidence of supernova
  34. Fermi-LAT Gamma-ray Observations of IceCube-211117A
  35. GRB211118A: Swift/BAT-GUANO detection outside the coded FOV
  36. Fermi trigger No 658971499: Global MASTER-Net observations report
  37. Fermi-LAT Gamma-ray Observations of IceCube-211116A
  38. IceCube Alert 211116.44: Global MASTER-Net observations report
  39. Fermi trigger No 658755664: Global MASTER-Net observations report
  40. Fermi trigger No 658764238: Global MASTER-Net observations report
  41. GRB 211115A: CALET Gamma-Ray Burst Monitor detection
  42. Fermi trigger No 658686687: Global MASTER-Net observations report
  43. Fermi GRB 211112A: Global MASTER-Net observations report
  44. Fermi trigger No 658214822: Global MASTER-Net observations report
  45. GRB 211107B: Swift-XRT afterglow detection
  46. GRB 211106A: VLT/FORS2 optical observations
  47. GRB 211106A, GROND observations
  48. GRB 211106A: Swift-XRT afterglow detection
  49. Fermi GRB 211109B: Global MASTER-Net observations report
  50. GRB 211023A: SAO RAS optical observations
  51. GRB 211107B: Swift-XRT observations
  52. MeerLICHT follow-up of GRB 211106A
  53. GRB 211107B: Swift ToO observations
  54. Fermi GRB 211109A: Global MASTER-Net observations report
  55. GRB 211107B: Swift/BAT detection
  56. GRB 211023A: A BdHN of type I
  57. GRB 211106A: Swift-XRT observations
  58. GRB 211106A: Swift ToO observations
  59. GRB 211106A: Swift/BAT-GUANO candidate arcminute localization of a short burst
  60. GRB 211105A: MASTER optical inspection
  61. GRB 211105A: Swift/BAT-GUANO detection outside the coded FOV
  62. GRB 211023A: continued 1.3m DFOT Optical Observations and possible jet break
  63. Fermi trigger No 657742914: Global MASTER-Net observations report
  64. GRB 211023B: Subaru optical observation
  65. Fermi GRB 211102A: Global MASTER-Net observations report
  66. GRB 211024B: Optical afterglow observation by Ondrejov D50
  67. GRB 211024A: 1.3m DFOT observations
  68. Fermi GRB 211031A: Global MASTER-Net observations report
  69. GRB 211023A: 1.3m DFOT Optical Observations
  70. Konus-Wind detection of GRB 211023A
  71. GRB 2121023B: 6 GHz VLA radio upper limit
  72. GRB 211023A: Terskol optical observations
  73. AMON NuEm-211020A: No Candidate Counterparts from Swift-XRT follow up observations
  74. GRB 211023A: continued Mondy optical observations
  75. GRB 211024A: Swift-XRT source 4 is not an afterglow.
  76. GRB 211023B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  77. Fermi GRB 211027A: Global MASTER-Net observations report
  78. GRB 211024A: Possible afterglow candidate from GIT
  79. GRB 211024A: Swift-XRT observations
  80. GRB 211018A: Swift-XRT observations
  81. GRB 211024A: Swift ToO observations
  82. GRB 211024A: Swift/BAT-GUANO detection and candidate arcminute localization of a short burst
  83. GRB 211023A: Mondy optical observations
  84. GRB 211023B: Gemini-North Optical Observations
  85. Swift GRB 211025A: Global MASTER-Net observations report
  86. GRB 211023B: LDT Optical Afterglow Detection
  87. GRB 211025A: Swift/UVOT Detection
  88. GRB 211023A: 1.5m OSN optical observation
  89. GRB 210610B: Sintesz-Newton/CrAO optical observations
  90. GRB 211024B: Nanshan/NEXT optical afterglow detection
  91. GRB 210919A: FORS2/VLT observations
  92. GRB 211023A: OAJ Bright Afterglow Confirmation
  93. Swift GRB 211024B: Global MASTER-Net observations report
  94. Fermi-LAT Gamma-ray Observations of IceCube-211023A
  95. GRB 211023A: MASTER OT J045237.07+851925.2 - optical counterpart discovery
  96. GRB 211023B: Swift/UVOT Detection
  97. GRB 211023B: RATIR Optical and NIR Upper Limits
  98. Fermi GRB 211023A: Global MASTER-Net observations report
  99. Swift GRB 211023B: Global MASTER-Net observations report
  100. Fermi GRB 211024A: Global MASTER-Net observations report

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov