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"

5163 results found.

  1. GRB 201223A: NOT optical upper limit and NEXT powerlaw decay
  2. Baksan Neutrino Observatory Alert 201223.60: Global MASTER-Net observations report
  3. Swift-XRT observations of Icecube 201222A
  4. Fermi trigger No 630389391: Global MASTER-Net observations report
  5. GRB 201221D: Archival PS1 Imaging of the Putative Host Galaxy
  6. GRB 201221D: candidate optical counterpart from the NOT
  7. GRB 201221A: Swift-BAT refined analysis
  8. GRB 201221D: Prompt enhanced Swift-XRT position
  9. GRB 201221A: Swift-XRT refined Analysis
  10. Swift Trigger 1014012: possible GRB 201221C
  11. GRB 201221A: Enhanced Swift-XRT position
  12. GRB 201221A: VLT/X-shooter afterglow discovery and spectroscopic redshift z = 5.7
  13. GRB 201221A: Prompt enhanced Swift-XRT position
  14. GRB 201221A: Swift detection of a burst
  15. Konus-Wind observation of GRB 201218A
  16. Fermi GRB 201218B: Global MASTER-Net observations report
  17. Baksan Neutrino Observatory Alert 201216.94: Global MASTER-Net observations report
  18. Fermi GRB 201216A: Global MASTER-Net observations report
  19. GRB 201208A: Fermi GBM observation
  20. GRB 201207A: AstroSat CZTI detection
  21. Fermi GRB 201208A: Global MASTER-Net observations report
  22. Swift follow-up observations of the flat spectrum radio quasar PMN J0206-1150 in the error region of IceCube-201130A
  23. GRB 201203A: Swift-XRT afterglow detection
  24. IceCube Alert 201130.85: Global MASTER-Net observations report
  25. Baksan Neutrino Observatory Alert 201128.90: Global MASTER-Net observations report
  26. GRB 201128A: Swift-XRT refined Analysis
  27. IceCube-201114A: Updated photometry for three DECam candidate optical counterparts
  28. IceCube Alert 201124.34: Global MASTER-Net observations report
  29. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-201124A
  30. GRB 201015A radio afterglow with e-MERLIN
  31. Fermi GRB 201120B: Global MASTER-Net observations report
  32. Baksan Neutrino Observatory Alert 201120.43: Global MASTER-Net observations report
  33. ZTF20acozryr/AT2020yxz (GRB 201103B): correction to the GCN #28883 CrAO/ZTSh optical observations
  34. GRB 201116A: OSN Afterglow Candidate
  35. Fermi trigger No 627198169: Global MASTER-Net observations report
  36. IceCube-201114A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  37. ZTF20acozryr/AT2020yxz (GRB 201103B): CrAO/ZTSh optical observations
  38. Fermi GRB 201111A: Global MASTER-Net observations report
  39. Fermi GRB 201104A: Global MASTER-Net observations report
  40. Fermi GRB 201031B: Global MASTER-Net observations report
  41. GRB 201031B: BALROG localization (Fermi Trigger 625859489 / GRB 201031744)
  42. GRB 201031B: Fermi GBM Final Real-time Localization
  43. GRB 201029A: Swift-XRT refined Analysis
  44. Fermi trigger No 625695596: Global MASTER-Net observations report
  45. GRB 201027A: Swift-XRT refined Analysis
  46. GRB 201026A: Swift-XRT refined Analysis
  47. GRB 201020A: 1.3m DFOT, optical upper limits
  48. GRB 201024A: 1.3m DFOT optical observations
  49. GRB 201020B: 1.3m DFOT continued optical follow-up observations
  50. GRB 201024A: MITSuME Akeno optical upper limits
  51. GRB 201024A: Swift-XRT refined Analysis
  52. GRB 201024A: VIRT optical observations
  53. GRB 201020B: Redshift from GTC/OSIRIS
  54. GRB 201024A: Redshift from GTC/OSIRIS
  55. GRB 201024A: BOOTES-2/TELMA early optical observation and 1.5m OSN follow-up
  56. GRB 201024A: MASTER correction to GCN 28760
  57. Swift GRB201024A: Global MASTER-Net OT detection
  58. Swift GRB201024.12: Global MASTER-Net observations report
  59. GRB 201021C: Swift-XRT refined Analysis
  60. GRB 201020A: Swift/UVOT Observations
  61. GRB 201020A: Swift-XRT refined Analysis
  62. GRB 201020A: Swift detection of a burst with an optical counterpart.
  63. GRB 201017A: SAO RAS optical observations
  64. GRB 201015A: 6 GHz VLA radio afterglow candidate detection
  65. GRB 201017A: Swift-XRT refined Analysis
  66. GRB 201015A: MMT afterglow imaging
  67. GRB 201015A: Assy and Mondy optical observations
  68. GRB 201015A: Swift-XRT refined Analysis
  69. GRB 201015A: Enhanced Swift-XRT position
  70. GRB 201015A: GOTO confirmation of afterglow detection
  71. GRB 201015A: NOT optical afterglow confirmation
  72. GRB 201015A: Swift-XRT observations
  73. IceCube Alert 201014.09: Global MASTER-Net observations report
  74. GRB 201013A: Swift-XRT refined Analysis
  75. SGR 1830-0645: pre-discovery detection in Swift/BAT
  76. Fermi trigger No 624121589: Global MASTER-Net observations report
  77. Swift detection of a new SGR 1830-0645 or a short GRB 201010A
  78. Fermi trigger No 623846261: Global MASTER-Net observations report
  79. GRB 201006A: Swift-XRT refined Analysis
  80. Baksan Neutrino Observatory Alert 201006.88: Global MASTER-Net observations report
  81. IceCube-200926A: No significant detection in HAWC
  82. Fermi GRB 200929A: Global MASTER-Net observations report
  83. GRB 200928A: Fermi GBM Final Localization
  84. IceCube Alert 200926.94: Global MASTER-Net observations report
  85. Fermi GRB 200925A: Global MASTER-Net observations report
  86. Fermi GRB 200924A: Global MASTER-Net observations report
  87. GRB 200924B: Fermi GBM Final Localization
  88. Fermi trigger No 622618714: Global MASTER-Net observations report
  89. GRB 200924A: Fermi GBM Final Real-time Localization
  90. Fermi GRB 200923A: Global MASTER-Net observations report
  91. IceCube Alert 200921.80: Global MASTER-Net observations report
  92. Swift GRB 200922A: Global MASTER-Net observations report
  93. GRB 200922A: Swift-XRT refined Analysis
  94. GRB 200922B: Fermi GBM Final Real-time Localization
  95. Fermi GRB 200919C: Global MASTER-Net observations report
  96. GRB 200917A: Swift-XRT refined Analysis
  97. IPN triangulation of GRB 200916B (short)
  98. IceCube Alert 200914.00: Global MASTER-Net observations report
  99. IPN triangulation of GRB 200907A (short)
  100. Fermi GRB 200909A: 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