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"

36129 results found.

  1. GRB 211227A: Swift-XRT refined Analysis
  2. GRB 211227A: Swift-BAT refined analysis
  3. GRB 211227A: A possible short GRB with extended emission at z = 0.228?
  4. GRB 211227A: Liverpool Telescope upper limits
  5. GRB 211227A: Enhanced Swift-XRT position
  6. GRB 211227A: LCO Optical Observations
  7. GRB 211227A: Nanshan/NEXT optical observations and host galaxy candidate
  8. GRB 211227A: MAXI/GSC detection
  9. GRB 211227A: BOOTES-2/TELMA optical upper limit
  10. GRB 211221A: Swift/UVOT Upper Limits
  11. GRB 211227A: Swift detection of a burst
  12. GRB 211226A: Swift/BAT-GUANO detection outside the coded FOV
  13. GRB 211225B: Swift-BAT refined analysis
  14. GRB 211225A: MITSuME Akeno optical upper limits
  15. GRB 211226A: AGILE/MCAL detection of a burst
  16. Swift GRB 211225B: Global MASTER-Net observations report
  17. Fermi GRB 211225C: Global MASTER-Net observations report
  18. GRB 211225C: Fermi GBM Final Real-time Localization
  19. GRB 211225B: Swift detection of a burst
  20. GRB 211225A/MAXI J0827-071: MAXI/GSC detection
  21. GRB 211224A: Fermi GBM Final Real-time Localization
  22. GRB 211106A: Third HST Observation
  23. GRB 211211A: observations with the 3.6m Devasthal Optical Telescope
  24. GRB 211223C: Swift-BAT refined analysis
  25. GRB 211223C: BOOTES-4/MET optical upper limit
  26. Swift GRB 211223C: Global MASTER-Net observations report
  27. GRB 211223A: Insight-HXMT/HE detection
  28. Fermi GRB 211223B: Global MASTER-Net observations report
  29. Fermi GBM Sub-Threshold Detection of GRB 211221A
  30. Fermi GBM Sub-Threshold Detection of GRB 211207A
  31. GRB 211221A: Swift-BAT refined analysis
  32. GRB 211223C: Swift detection of a burst
  33. GRB 211223B: Fermi GBM Final Real-time Localization
  34. GRB 211223A: GECAM detection
  35. GRB 211221A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  36. GRB 211219B: AstroSat CZTI detection
  37. GRB 211219A: AstroSat CZTI detection
  38. Fermi GRB 211222A: Global MASTER-Net observations report
  39. GRB 211221A: Swift-XRT refined Analysis
  40. GRB 211222A: Fermi GBM Final Real-time Localization
  41. GRB 211221A: BOOTES-4/MET optical upper limit
  42. GRB 211218A: MITSuME Akeno optical upper limits
  43. GRB 211221A: MeerLICHT optical limits
  44. GRB 211221A: NOT optical limits
  45. GRB 211221A: Enhanced Swift-XRT position
  46. Swift GRB 211221A: Global MASTER-Net observations report
  47. GRB 211221A: Swift detection of a burst
  48. GRB 211219A: AGILE detection
  49. GRB 211219A: Swift/BAT-GUANO detection outside the coded FOV
  50. Fermi GRB 211219B: Global MASTER-Net observations report
  51. GRB 211219B: Fermi GBM Final Real-time Localization
  52. Fermi GRB 211219A: Global MASTER-Net observations report
  53. GRB 211219A: Fermi GBM Final Real-time Localization
  54. GRB 211211A: MMT/MMIRS Observations Indicate Fading of K-band Source
  55. GRB 211216A: Fermi GBM observation
  56. GRB 211218A, MAXI J0909-041: MAXI/GSC detection
  57. GRB 211106A: XMM-Newton monitoring campaign detections
  58. IceCube-211216B: Upper limits from Fermi-GBM Observations
  59. IceCube-211216A: Upper limits from Fermi-GBM Observations
  60. GRB 211217A: GECAM detection
  61. GRB 211216A: Swift/BAT-GUANO detection outside the coded FOV
  62. Fermi GRB 211216B: Global MASTER-Net observations report
  63. GRB 211216B: GECAM detection
  64. GRB 211216B: Fermi GBM Final Real-time Localization
  65. IceCube-211216A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  66. GRB 211211A: TNG NIR observations
  67. GRB 211216A: GECAM detection
  68. GRB 211216A: BALROG localization (Fermi Trigger 661329957 / GRB 211216282)
  69. Fermi GRB 211216A: Global MASTER-Net observations report
  70. GRB 211216A: Fermi GBM Final Real-time Localization
  71. GRB 211211A: Insight-HXMT/HE detection
  72. GRB 211211A - Gemini K-band detection
  73. GRB 211211A: SAO RAS optical observations
  74. GRB 211211A: AbAO optical observations
  75. GRB 211211A: GMG upper limit
  76. GRB 211211A: redshift estimation and SPI-ACS/INTEGRAL detection
  77. GRB 211211A: Very fast decay observed from CAFOS/2.2mCAHA
  78. GRB 211211A: Further observations from CAFOS/2.2m CAHA
  79. GRB 211211A: HCT and GIT optical follow up observations
  80. GRB 211211A: CALET Gamma-Ray Burst Monitor detection
  81. Fermi GRB 211212A: Global MASTER-Net observations report
  82. GRB 211211A: incorrect E_iso value in GCN 31221
  83. GRB 211211A: Swift/UVOT detection
  84. GRB 211211A: NOT optical spectroscopy
  85. GRB 211211B: GECAM detection
  86. Fermi GRB 211212B: Global MASTER-Net observations report
  87. GRB 211211A: Afterglow detection from CAFOS/2.2m CAHA
  88. GRB 211211A: MITSuME Akeno optical observation
  89. Swift GRB 211211A: Global MASTER-Net observations report
  90. GRB 211212B: Fermi GBM Final Real-time Localization
  91. GRB 211211A: LCO Optical Observations
  92. GRB 211211A: Nanshan/NEXT optical observations
  93. GRB 211211A: Swift-XRT refined Analysis
  94. GRB 211212A: Fermi GBM Final Real-time Localization
  95. GRB 211211A: Fermi GBM observation
  96. GRB 211211A: Swift-BAT refined analysis
  97. Fermi GRB 211211B: Global MASTER-Net observations report
  98. GRB 211211B: Fermi GBM Final Real-time Localization
  99. Fermi GRB 211211A: Global MASTER-Net observations report
  100. GRB 211211A: Enhanced Swift-XRT position

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