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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"

19701 results found.

  1. GRB 210708B: Swift-BAT refined analysis
  2. GRB 210708A: Swift/UVOT Upper Limits
  3. GRB 210702A: ALMA detection
  4. GRB 210708A: Swift detection of a burst
  5. GRB 210706A: GIT optical upper limits
  6. GRB 210704A: OAJ T80 multi-color detections
  7. GRB 210706A: Swift-XRT afterglow detection
  8. GRB 210706A: Swift ToO observations
  9. GRB 210704A: OSIRIS/GTC spectroscopy
  10. GRB 210704A: RATIR optical upper limits
  11. GRB 210704A: Swift/UVOT Upper Limits
  12. GRB 210704B: AstroSat CZTI detection
  13. GRB 210704A: TNG detection of the optical afterglow candidate
  14. GRB 210704A: Assy optical afterglow candidate
  15. GRB 210704A: DDOTI upper limit
  16. GRB 210704A: possible local hosts
  17. GRB 210704A: Swift-XRT afterglow detection
  18. GRB 210704A: AstroSat CZTI detection
  19. IceCube-210516A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  20. IceCube-210510A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  21. GRB 210704A: Swift ToO observations
  22. GRB 210702A, Swift-BAT refined analysis
  23. GRB 210702A: Chilescope optical observations
  24. GRB 210702A: iTelescope optical afterglow observations
  25. GRB 210702A: Swift-XRT refined Analysis
  26. GRB 210702A: VLT/X-shooter redshift
  27. GRB 210702A: preliminary Swift/UVOT photometry
  28. GRB210702A: MeerLICHT multi-colour photometry
  29. GRB 210702A: Swift detection of a burst with a bright optical counterpart
  30. IceCube-210629A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  31. Fermi-LAT Gamma-ray Observations of IceCube-210629A
  32. GRB 210619B: Sayan observatory 1.6-m telescope observations
  33. GRB 210626A: GIT optical upper limit
  34. GRB 210626A: Swift-XRT afterglow detection
  35. GRB 210626A: Swift ToO observations
  36. GRB210619B: optical afterglow detection from Konkoly Observatory
  37. GRB 210622A: Swift-XRT observations
  38. GRB 210610B: T-CAT optical observations
  39. GRB 210618A: Swift-XRT afterglow detection
  40. GRB 210622A: Swift ToO observations
  41. GRB 210619B: Even further SAO RAS optical observations
  42. GRB 210619B: Mini-MegaTORTORA early optical observations
  43. GRB 210619B: Further SAO RAS optical observations
  44. GRB 210619B: AbAO optical observations
  45. Swift Trigger 1057131: detection of a burst from SGR Swift J1555.2-5402
  46. GRB 210619B: iTelescope optical afterglow observation
  47. GRB 210619B: SAO RAS optical observations
  48. GRB 210619B: SEDM Optical Observations
  49. GRB 210619B: REM optical/NIR afterglow detection
  50. GRB 210619B: GIT optical follow-up and confirmation of jet-break
  51. GRB 210619B: Liverpool Telescope First Hour Observations
  52. GRB 210619B: Swift/UVOT Detection
  53. GRB 210619B: Liverpool telescope imaging of a red afterglow
  54. GRB 210619B: SARA-KP 0.9m Optical Afterglow Detection
  55. GRB 210619B: Enhanced Swift-XRT position
  56. GRB 210619B: iTelescope T18 detection
  57. GRB 210619B: Swift detection of a bright burst and optical counterpart
  58. GRB 210618A: Swift/UVOT Upper Limits
  59. GRB 210618A: DDOTI upper limit for the optical afterglow
  60. GRB 210618A: Swift detection of a burst
  61. GRB 210610B: Swift/UVOT Detection
  62. GRB 210610A: Swift/UVOT Detection
  63. GRB 201008A: Fermi GBM observation
  64. GRB 210610B: REM optical/NIR observations of the afterglow
  65. Swift ToO Observations of HAWC transient J0020+3108
  66. GRB 210605B: Swift-XRT afterglow detection
  67. GRB 210610A: Fermi GBM observations
  68. GRB 210610B: Further SAO RAS optical observations
  69. GRB 210610A: SAO RAS optical observations
  70. GRB 210610B: optical photometry of afterglow at INASAN/Simeiz
  71. Swift-BAT Trigger 1055000: Swift detection of an outburst from 4U 1543-47
  72. GRB210610B: SARA-KP 0.9m Optical Afterglow Detection
  73. GRB 210610B: MITSuME Akeno optical observation
  74. GRB 210610B: Liverpool Telescope optical photometry
  75. GRB 210610B: Swift-BAT refined analysis
  76. GRB 210610B: Zwicky Transient Facility afterglow detection
  77. GRB 210610B: optical afterglow observations
  78. GRB 210610B: University of Siena Observatory optical photometry of the afterglow
  79. Konus-Wind detection of GRB 210610A
  80. GRB 210610B: GOTO confirmation of afterglow detection
  81. GRB 210610A: RATIR Optical and NIR Detection
  82. GRB 210610B: RATIR Optical and NIR Observations
  83. GRB 210610B: Enhanced Swift-XRT position
  84. GRB 210610B: SAO RAS optical observations
  85. GRB 210610B: correction to GCN 30181
  86. GRB 210610B: iTelescope optical afterglow observations
  87. GRB210610B: MeerLICHT multi-colour photometry
  88. GRB 210610B: GIT optical detection
  89. GRB 210606A: Swift-XRT afterglow detection
  90. GRB 210610B: Swift detection of a burst with bright optical afterglow
  91. GRB 210610A: MITSuME Ishigaki optical observation
  92. GRB210610A: MeerLICHT multi-colour photometry
  93. GRB 210610A: Enhanced Swift-XRT position
  94. GRB 210610A: GIT optical detection
  95. GRB 210610A: Xinglong-2.16m optical afterglow observations
  96. GRB 210610A: MITSuME Akeno optical observation
  97. GRB 210610A: Swift detection of a burst with an optical counterpart
  98. Fermi-LAT Gamma-ray Observations of IceCube-210608A
  99. IPN triangulation of GRB 210606B
  100. IceCube-210608A: IceCube observation of a high-energy neutrino candidate track-like event

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