Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. 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"

36197 results found.

  1. GRB 210702A: VLT/X-shooter redshift
  2. GRB 210702A: preliminary Swift/UVOT photometry
  3. GRB 210702A: Swift/UVOT redshift
  4. Swift GRB 210702A: Global MASTER-Net observations report
  5. GRB 210702A: Swift detection of a burst with a bright optical counterpart
  6. IceCube-210629A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  7. IceCube-210629A: Upper limits from Fermi-GBM Observations
  8. GRB 210627B: GECAM detection
  9. GRB 210619B: Sayan observatory 1.6-m telescope observations
  10. GRB 210626A: Swift/XRT afterglow confirmation
  11. GRB 210626A: Fermi GBM observation
  12. GRB 210626A: CAHA 2.2m telescope optical limit
  13. GRB 210619B: Deep CAHA 2.2m detection and late-time light curve behavior
  14. GRB 210626A: Ondrejov D50 optical limit
  15. GRB 210626A: GIT optical upper limit
  16. Fermi GRB 210627B: Global MASTER-Net observations report
  17. GRB 210627B: BALROG localization (Fermi Trigger 646509445/ GRB 210627748)
  18. GRB 210627B: Fermi GBM Final Real-time Localization
  19. Fermi GRB 210627A: Global MASTER-Net observations report
  20. GRB 210627A: Fermi GBM Final Real-time Localization
  21. GRB 210626A: Swift-XRT afterglow detection
  22. Fermi GRB 210626A: Global MASTER-Net observations report
  23. GRB 210626A: Swift ToO observations
  24. GRB 210626A: Swift/BAT-GUANO detection and arcminute localization
  25. GRB 150428A: late-time radio observations
  26. GRB 210626A: Fermi GBM Final Real-time Localization
  27. GRB 210618A: 1.5m OSN optical upper limit
  28. Fermi GRB 210625A: Global MASTER-Net observations report
  29. GRB 210625A: Fermi GBM Final Real-time Localization
  30. IPN triangulation of GRB 210624A (short)
  31. GRB 210622A: Swift-XRT observations
  32. GRB 210610B: T-CAT optical observations
  33. GRB 210619B: ASIM observation
  34. GRB 210618A: Swift-XRT afterglow detection
  35. GRB 210622A: Swift ToO observations
  36. GRB 210619B: Even further SAO RAS optical observations
  37. GRB 210619B: Mini-MegaTORTORA early optical observations
  38. Fermi GRB 210622B: Global MASTER-Net observations report
  39. GRB 210622A: Fermi GBM detection
  40. GRB 210619B: Abbey Ridge Observatory optical afterglow observation
  41. GRB 210619B: SPI-ACS/INTEGRAL observations
  42. GRB 210619B: Further SAO RAS optical observations
  43. GRB 210622A: Swift/BAT-GUANO detection and arcminute localization of a long burst
  44. GRB 210619B: possibility of lensed visible afterglow?
  45. GECAM detection of GRB 210622B
  46. GRB 210619B: AbAO optical observations
  47. GRB 210622B: Fermi GBM Final Real-time Localization
  48. GRB 210622A: Fermi GBM Final Real-time Localization
  49. GRB 210619B: NOT optical observations
  50. GRB 210619B: 1.5m OSN optical observation
  51. GRB 210619B: iTelescope optical afterglow observation
  52. GRB 210619B: SAO RAS optical observations
  53. GRB 210619B: SEDM Optical Observations
  54. GRB 210619B: TNG NIR observations of the afterglow
  55. GRB 210619B: REM optical/NIR afterglow detection
  56. Fermi GRB 210621A: Global MASTER-Net observations report
  57. GRB 210619B: GIT optical follow-up and confirmation of jet-break
  58. GRB 210621A: Fermi GBM Final Real-time Localization
  59. GRB 210619B: CALET Gamma-Ray Burst Monitor detection
  60. GRB 210619B: SRG/ART-XC detection
  61. GRB 210619B: Swift-BAT refined analysis
  62. GRB 210619B: steepening of the decay observed at the D50
  63. GRB 210619B: Liverpool Telescope First Hour Observations
  64. GRB 210619B: Fermi GBM detection
  65. GRB 210619B: Swift/UVOT Detection
  66. GRB 210619B: Xinglong TNT optical observations
  67. Konus-Wind detection of GRB 210619B
  68. GRB 210619B: CAHA 2.2m photometric monitoring
  69. GRB 210619B: Liverpool Telescope r'-band observations
  70. GRB 210619B: KAIT Optical Detection
  71. GRB 210619B: Redshift from OSIRIS/GTC
  72. GRB 210619B: Liverpool telescope imaging of a red afterglow
  73. GRB 210619B: Fermi-LAT detection
  74. GRB 210619B: Swift-XRT refined Analysis
  75. GRB 210619B: SARA-KP 0.9m Optical Afterglow Detection
  76. GRB 210619B: Enhanced Swift-XRT position
  77. GRB 210619B: iTelescope T18 detection
  78. GECAM detection of GRB 210619B
  79. GRB 210619B: Ondrejov D50 detection
  80. GRB 210619B: Swift detection of a bright burst and optical counterpart
  81. GRB 210619A: BALROG localization (Fermi Trigger 645799548 / GRB 210619532)
  82. GRB 210619A: Fermi GBM Final Real-time Localization
  83. GRB 210618A: Swift/UVOT Upper Limits
  84. GRB 210618A: BOOTES-2/TELMA optical upper limit
  85. GRB 210618A: Swift-BAT refined analysis
  86. GRB 210618A: Fermi GBM observation
  87. GRB 210618A: Swift-XRT observations
  88. GRB 210618A: DDOTI upper limit for the optical afterglow
  89. GRB 210618A: Swift detection of a burst
  90. GRB 210618A: Fermi GBM Final Real-time Localization
  91. GRB 210610B: Swift/UVOT Detection
  92. GRB 210610A: Swift/UVOT Detection
  93. GRB 210610B: CrAO/ZTSH continued optical observations and light curve
  94. GRB 210610B: AbAO optical observations
  95. GRB 201008A: Fermi GBM observation
  96. GRB 210323B: Fermi GBM observation
  97. Fermi GRB 210615A: Global MASTER-Net observations report
  98. GRB 210615A: Fermi GBM Final Real-time Localization
  99. GRB 210610B: REM optical/NIR observations of the afterglow
  100. Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation

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