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"

16152 results found.

  1. GRB 210626A: Ondrejov D50 optical limit
  2. GRB 210626A: GIT optical upper limit
  3. GRB 210618A: 1.5m OSN optical upper limit
  4. GRB210619B: optical afterglow detection from Konkoly Observatory
  5. GRB 210610B: T-CAT optical observations
  6. GRB 210619B: Even further SAO RAS optical observations
  7. GRB 210619B: Mini-MegaTORTORA early optical observations
  8. GRB 210619B: Abbey Ridge Observatory optical afterglow observation
  9. GRB 210619B: Further SAO RAS optical observations
  10. GRB 210619B: possibility of lensed visible afterglow?
  11. GRB 210619B: AbAO optical observations
  12. GRB 210619B: NOT optical observations
  13. GRB 210619B: 1.5m OSN optical observation
  14. GRB 210619B: iTelescope optical afterglow observation
  15. GRB 210619B: SAO RAS optical observations
  16. GRB 210619B: SEDM Optical Observations
  17. GRB 210619B: REM optical/NIR afterglow detection
  18. GRB 210619B: GIT optical follow-up and confirmation of jet-break
  19. GRB 210619B: steepening of the decay observed at the D50
  20. GRB 210619B: Liverpool Telescope First Hour Observations
  21. GRB 210619B: Xinglong TNT optical observations
  22. GRB 210619B: KAIT Optical Detection
  23. GRB 210619B: Liverpool telescope imaging of a red afterglow
  24. GRB 210619B: SARA-KP 0.9m Optical Afterglow Detection
  25. GRB 210619B: iTelescope T18 detection
  26. GRB 210619B: Ondrejov D50 detection
  27. Swift GRB210619.99: Global MASTER-Net OT detection
  28. GRB 210619B: Swift detection of a bright burst and optical counterpart
  29. Swift GRB210619.99: Global MASTER-Net OT detection
  30. GRB 210618A: Swift/UVOT Upper Limits
  31. GRB 210618A: BOOTES-2/TELMA optical upper limit
  32. GRB 210618A: DDOTI upper limit for the optical afterglow
  33. GRB 210610B: Swift/UVOT Detection
  34. GRB 210610A: Swift/UVOT Detection
  35. GRB 210610B: CrAO/ZTSH continued optical observations and light curve
  36. GRB 210610B: AbAO optical observations
  37. GRB 210610B: REM optical/NIR observations of the afterglow
  38. Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
  39. GRB 210610B: iTelescope optical afterglow observations
  40. GRB 210610B: Further SAO RAS optical observations
  41. GRB 210610A: SAO RAS optical observations
  42. GRB 210610B: optical observations from Burke-Gaffney Observatory and Abbey Ridge Observatory
  43. GRB 210610B: Continued KAIT Optical Detection
  44. GRB 210610B: optical photometry of afterglow at INASAN/Simeiz
  45. GRB210610B: SARA-KP 0.9m Optical Afterglow Detection
  46. GRB 210610B: MITSuME Akeno optical observation
  47. GRB 210610B: VLA detection
  48. GRB 210610B: ALMA detection
  49. GRB 210610B: Liverpool Telescope optical photometry
  50. GRB 210610B: CrAO/ZTSH optical observations and light curve
  51. GRB 210610A: CrAO/ZTSH optical observations
  52. GRB 210610B: CrAO/ZTSH optical observations (correction to the GCN circ. 30212)
  53. GRB 210610A: CrAO/ZTSH optical observations
  54. GRB 210610B: Zwicky Transient Facility afterglow detection
  55. GRB 210610B: optical afterglow observations
  56. GRB 210610B: KAIT Optical Detection
  57. GRB 210610A: KAIT Optical Detection
  58. GRB 210610B: University of Siena Observatory optical photometry of the afterglow
  59. GRB 210610B: GOTO confirmation of afterglow detection
  60. GRB 210610A: RATIR Optical and NIR Detection
  61. GRB 210610B: RATIR Optical and NIR Observations
  62. GRB 210610B: Photometry and phot-redshift from Legacy Survey, PanSTAR, and SDSS
  63. GRB 210610B: SAO RAS optical observations
  64. GRB 210610A: 1.5m OSN optical observation
  65. GRB 210610B: correction to GCN 30181
  66. GRB 210610B: NOT optical observations and tentative redshift
  67. GRB 210610B: iTelescope optical afterglow observations
  68. GRB210610B: MeerLICHT multi-colour photometry
  69. GRB 210610B: CrAO/ZTSh optical afterglow photometry
  70. GRB 210610B: BOOTES-2/TELMA optical observation
  71. GRB 210610B: CrAO/ZTSh optical observations
  72. GRB 210610B: GIT optical detection
  73. Swift GRB210610.83: Global MASTER-Net OT detection
  74. GRB 210610B: Swift detection of a burst with bright optical afterglow
  75. GRB 210610A: MITSuME Ishigaki optical observation
  76. GRB210610A: MeerLICHT multi-colour photometry
  77. Swift GRB 210610A: MASTER optical counterpart observation
  78. GRB 210610A: Xinglong-2.16m redshift
  79. GRB 210610A: GIT optical detection
  80. GRB 210610A: Xinglong-2.16m optical afterglow observations
  81. GRB 210610A: MITSuME Akeno optical observation
  82. GRB 210610A: Swift detection of a burst with an optical counterpart
  83. GRB 210606A: 1.5m OSN optical upper limit
  84. GRB 210528B: MITSuME Akeno optical upper limits
  85. GRB 210527A: Swift/UVOT Observations
  86. GRB 210527A: GIT optical upper limit
  87. GRB 210527A: MITSuME Akeno optical upper limits
  88. GRB 210527A: RATIR Optical and NIR Observations
  89. GRB 210306A: LBT observations of the likely host galaxy
  90. ZTF21aayokph (AT2021lfa): LBT optical observations
  91. ZTF21aayokph (AT2021lfa): continued Assy optical observations
  92. GRB 210517A: KCT optical upper limit
  93. GRB 210517A: Swift/UVOT Upper Limits
  94. GRB 210515C: Swift/UVOT Upper Limits
  95. GRB 210517A: VLT/X-shooter optical afterglow and redshift
  96. GRB 210515C: LCO Optical Upper Limit
  97. GRB 210504A: LCO Optical Afterglow Detection
  98. GRB 210514A: Swift/UVOT Upper Limits
  99. GRB210510A: Optical afterglow candidate from the Zwicky Transient Facility
  100. Short GRB 210323A: likely host galaxy detection

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