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"

26125 results found.

  1. GRB 210619B: Fermi-LAT detection
  2. GRB 210619B: Swift-XRT refined Analysis
  3. GRB 210619B: SARA-KP 0.9m Optical Afterglow Detection
  4. GRB 210619B: Enhanced Swift-XRT position
  5. GRB 210619B: iTelescope T18 detection
  6. GECAM detection of GRB 210619B
  7. GRB 210619B: Ondrejov D50 detection
  8. Swift GRB210619.99: Global MASTER-Net OT detection
  9. GRB 210619B: Swift detection of a bright burst and optical counterpart
  10. Swift GRB210619.99: Global MASTER-Net observations report
  11. Swift GRB210619.99: Global MASTER-Net OT detection
  12. GRB 210618A: Swift/UVOT Upper Limits
  13. GRB 210618A: BOOTES-2/TELMA optical upper limit
  14. GRB 210618A: Swift-BAT refined analysis
  15. GRB 210618A: Fermi GBM observation
  16. GRB 210618A: Swift-XRT observations
  17. GRB 210618A: DDOTI upper limit for the optical afterglow
  18. GRB 210618A: Swift detection of a burst
  19. Swift GRB210618.07: Global MASTER-Net observations report
  20. GRB 210610B: Swift/UVOT Detection
  21. GRB 210610A: Swift/UVOT Detection
  22. GRB 210610B: CrAO/ZTSH continued optical observations and light curve
  23. GRB 210610B: AbAO optical observations
  24. GRB 201008A: Fermi GBM observation
  25. GRB 210323B: Fermi GBM observation
  26. GRB 210610B: REM optical/NIR observations of the afterglow
  27. Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
  28. Swift ToO Observations of HAWC transient J0020+3108
  29. GRB 210605B: Swift-XRT afterglow detection
  30. GRB 210610A: Fermi GBM observations
  31. GRB 210610A: CAHA 2.2m Second Epoch
  32. GRB 210610B: iTelescope optical afterglow observations
  33. GRB 210610B: optical observations from Burke-Gaffney Observatory and Abbey Ridge Observatory
  34. GRB 210610B: Continued KAIT Optical Detection
  35. GRB 210610B: optical photometry of afterglow at INASAN/Simeiz
  36. GRB 210421B: Fermi GBM detection
  37. Swift GRB210612.54: Global MASTER-Net observations report
  38. Swift-BAT Trigger 1055000: Swift detection of an outburst from 4U 1543-47
  39. GRB210610B: SARA-KP 0.9m Optical Afterglow Detection
  40. GRB 210610B: MITSuME Akeno optical observation
  41. GRB 201228B: Fermi GBM observation
  42. GRB 210610B: VLA detection
  43. GRB 210610B: Liverpool Telescope optical photometry
  44. GRB 210610B: CrAO/ZTSH optical observations and light curve
  45. GRB 210610A: CrAO/ZTSH optical observations
  46. GRB 210610B: CrAO/ZTSH optical observations (correction to the GCN circ. 30212)
  47. GRB 210610A: CrAO/ZTSH optical observations
  48. GRB 210610A: CAHA 2.2m observations and light-curve behavior
  49. GRB 210606A: Fermi GBM detection
  50. GRB 210605B: Fermi GBM detection
  51. GRB 210610B: Swift-XRT refined Analysis
  52. GRB 210610B: Swift-BAT refined analysis
  53. GRB 210610B: Zwicky Transient Facility afterglow detection
  54. GRB 210610B: optical afterglow observations
  55. GRB 210610B: KAIT Optical Detection
  56. GRB 210610A: KAIT Optical Detection
  57. GRB 210610B: Spectroscopy and redshift confirmation with the Himalayan Chandra Telescope
  58. GRB 210610A: Spectroscopy and redshift confirmation with the Himalayan Chandra Telescope
  59. GRB 210610B: Fermi GBM detection
  60. GRB 210610B: University of Siena Observatory optical photometry of the afterglow
  61. Konus-Wind detection of GRB 210610A
  62. Konus-Wind detection of GRB 210610B
  63. GRB 210610B: AGILE detection
  64. GRB 210610B: Redshift confirmation from GTC
  65. GRB 210610B: GOTO confirmation of afterglow detection
  66. GRB 210610A: Swift-XRT refined Analysis
  67. GRB 210610A: RATIR Optical and NIR Detection
  68. GRB 210610B: RATIR Optical and NIR Observations
  69. GRB 210610B: Enhanced Swift-XRT position
  70. GRB 210610B: Photometry and phot-redshift from Legacy Survey, PanSTAR, and SDSS
  71. GRB 210610B: SAO RAS optical observations
  72. GRB 210610A: Swift-BAT refined analysis
  73. GRB 210610A: 1.5m OSN optical observation
  74. GRB 210610B: correction to GCN 30181
  75. GRB 210610B: NOT optical observations and tentative redshift
  76. GRB 210610B: iTelescope optical afterglow observations
  77. GRB210610B: MeerLICHT multi-colour photometry
  78. GRB 210610B: CrAO/ZTSh optical afterglow photometry
  79. GRB 210610B: BOOTES-2/TELMA optical observation
  80. Swift GRB 210610B: Global MASTER-Net observations report
  81. GRB 210610B: CrAO/ZTSh optical observations
  82. GRB 210610B: GIT optical detection
  83. Swift GRB210610.83: Global MASTER-Net OT detection
  84. GRB 210606A: Swift-XRT afterglow detection
  85. GRB 210610B: Swift detection of a burst with bright optical afterglow
  86. GRB 210610A: MITSuME Ishigaki optical observation
  87. GRB210610A: MeerLICHT multi-colour photometry
  88. Swift GRB 210610A: Global MASTER-Net observations report
  89. Swift GRB 210610A: MASTER optical counterpart observation
  90. GRB 210610A: Enhanced Swift-XRT position
  91. GRB 210610A: Xinglong-2.16m redshift
  92. GRB 210610A: GIT optical detection
  93. GRB 210610A: Xinglong-2.16m optical afterglow observations
  94. GRB 210610A: MITSuME Akeno optical observation
  95. GRB 210610A: Swift detection of a burst with an optical counterpart
  96. IPN triangulation of GRB 210606B
  97. GRB 210605B: Swift-XRT observations
  98. IPN triangulation of GRB 210605A (short)
  99. GRB 210606A: 1.5m OSN optical upper limit
  100. GECAM Sub-Threshold Detection of new magnetar Swift SGR J1555.2-5402

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