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"

21113 results found.

  1. GRB 210912A: BOOTES-5/JGT optical afterglow candidate
  2. GECAM observations of bursts from SGR J1935+2154 (2021-09-11T07 to 2021-09-12T08)
  3. Fermi trigger No 653093506: Global MASTER-Net observations report
  4. Fermi trigger No 653066776: Global MASTER-Net observations report
  5. Fermi trigger No 653084584: Global MASTER-Net observations report
  6. Fermi trigger No 653083551: Global MASTER-Net observations report
  7. Fermi trigger No 653079281: Global MASTER-Net observations report
  8. Fermi trigger No 653066130: Global MASTER-Net observations report
  9. Fermi trigger No 653072474: Global MASTER-Net observations report
  10. Fermi trigger No 653071808: Global MASTER-Net observations report
  11. Fermi trigger No 653054042: Global MASTER-Net observations report
  12. Fermi trigger No 653049776: Global MASTER-Net observations report
  13. Fermi trigger No 653022153: Global MASTER-Net observations report
  14. Fermi trigger No 653031163: Global MASTER-Net observations report
  15. Swift GRB210910.42: Global MASTER-Net observations report
  16. Fermi GBM observation of a bright flare in the direction of SGR 1935+2154
  17. Fermi trigger No 653010039: Global MASTER-Net observations report
  18. Fermi trigger No 652957973: Global MASTER-Net observations report
  19. Fermi trigger No 652944960: Global MASTER-Net observations report
  20. Fermi trigger No 652981861: Global MASTER-Net observations report
  21. GRB 210826A: further Swift-XRT observations
  22. GECAM observations of a series of bursts from SGR J1935+2154
  23. Fermi trigger No 652934203: Global MASTER-Net observations report
  24. Fermi trigger No 652927551: Global MASTER-Net observations report
  25. GRB 210619B: Maidanak and Assy optical observations, broken power law parametrization
  26. Fermi trigger No 652911693: Global MASTER-Net observations report
  27. Fermi trigger No 652906639: Global MASTER-Net observations report
  28. Fermi GRB 210909A: Global MASTER-Net observations report
  29. GRB 210905A: Swift/UVOT Upper Limits
  30. GRB 210905A: ATCA detection
  31. GRB 210905A: ALMA detection
  32. GRB 210905A, GROND observations
  33. Fermi trigger No 652585475: Global MASTER-Net observations report
  34. GRB 210610A: Maidanak and AbAO optical observations
  35. GRB 210905A: REM NIR afterglow detection
  36. GRB 210905A: VLT/X-shooter spectroscopic redshift
  37. GRB 210905A: Continued LCO Optical Observations
  38. GRB 210901A: Swift/UVOT Upper Limits
  39. Swift GRB 210905A: Global MASTER-Net observations report
  40. Fermi GRB 210904A: Global MASTER-Net observations report
  41. Swift GRB210903.59: Global MASTER-Net observations report
  42. Swift GRB210903.58: Global MASTER-Net observations report
  43. Swift GRB210903.58: Global MASTER-Net observations report
  44. Fermi GRB 210903A: Global MASTER-Net observations report
  45. Fermi GRB 210903B: Global MASTER-Net observations report
  46. GRB 210901A: GROND observations
  47. Swift GRB 210901A: Global MASTER-Net observations report
  48. GRB 210827A: further Swift-XRT observations
  49. GRB 210827A: Swift/UVOT Upper Limits
  50. Integral GRB210829.17: Global MASTER-Net observations report
  51. Integral GRB210829.14: Global MASTER-Net observations report
  52. Fermi GRB 210827A: Global MASTER-Net observations report
  53. Fermi GRB 210827B: Global MASTER-Net observations report
  54. GRB 210827A: Swift-XRT observations
  55. GRB 210827A: Swift ToO observations
  56. GRB 210827A: Swift/BAT-GUANO detection and arcminute localization
  57. GRB 210820A: CAHA 2.2m Optical Detection
  58. GRB 210824A: Swift/UVOT Upper Limits
  59. GRB 210826A: Swift/UVOT Upper Limits
  60. GRB 210826A: Swift-XRT observations
  61. GRB 210822A: CAHA 2.2m observations
  62. Fermi GRB 210826A: Global MASTER-Net observations report
  63. GRB 210826A: Tiled Swift observations
  64. Swift GRB210825.29: Global MASTER-Net observations report
  65. GRB 210822A: TSHAO continued optical observation
  66. GRB 210822A: VLA detection
  67. GRB 210822A: Swift/UVOT Detection
  68. Swift GRB 210824A: Global MASTER-Net observations report
  69. Fermi GRB 210824A: Global MASTER-Net observations report
  70. GRB 210822A: GROND observations
  71. GRB 210822A: Detection by GRBAlpha
  72. GRB 210820A: GROND observations
  73. Fermi trigger No 651306769: Global MASTER-Net observations report
  74. GRB 210820A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  75. GRB 210820A: Swift/UVOT Detection
  76. Fermi GRB 210822B: Global MASTER-Net observations report
  77. GRB 210822A: Nanshan/NEXT optical observations
  78. Swift GRB 210822A: Global MASTER-Net observations report
  79. GRB 210822A: KAIT Optical Afterglow Confirmation
  80. Fermi GRB 210821A: Global MASTER-Net observations report
  81. Swift GRB 210820A: Global MASTER-Net observations report
  82. Fermi trigger No 651110719: Global MASTER-Net observations report
  83. Swift GRB210818.68: Global MASTER-Net observations report
  84. Swift GRB 210818A: Global MASTER-Net observations report
  85. GRB 210726A: VLA radio afterglow detection
  86. IceCube-210730A: not observable by Fermi-GBM
  87. IceCube-210811A: Upper limits from Fermi-GBM Observations
  88. Fermi trigger No 650687034: Global MASTER-Net observations report
  89. GRB 210812A is consistent with being a lensed GRB
  90. IceCube-210811A: No Candidate Counterparts from the Zwicky Transient Facility
  91. Fermi GRB 210813A: Global MASTER-Net observations report
  92. Fermi-LAT Gamma-ray Observations of IceCube-210811A
  93. GRB 210807A: continued Assy, AbAO and Mondy observations
  94. Fermi GRB 210812A: Global MASTER-Net observations report
  95. SGR 1935+2154: SPI INTEGRAL observations on 2021 August 5
  96. GRB 210730A: Tautenburg observations
  97. GRB 210807A: Tautenburg observations
  98. IceCube Alert 210811.09: Global MASTER-Net observations report
  99. GRB 210807A: Detection by GRBAlpha
  100. GRB 210802A: Further Swift/XRT observation and afterglow confirmation

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