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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"

16251 results found.

  1. GRB 210704A: Lowell Discovery Telescope Optical Observations
  2. GRB 210704A: Continued Gemini-North NIR K-band Detections
  3. GRB 210704A: NOT optical observations and color change
  4. GRB210704A: Gemini near-infrared upper limits
  5. GRB 210704A: Assy optical afterglow upper limit
  6. GRB 210704A: OSIRIS/GTC Observations and Archival Detection of the Possible Host Galaxy
  7. GRB 210704A: Gemini-North Infrared Source Detection
  8. GRB 210704A: further TNG optical observations
  9. GRB 210708A: Swift/UVOT Upper Limits
  10. GRB 210702A: ATCA detection
  11. GRB 210702A: ALMA detection
  12. GRB 210704A: CAHA 2.2m telescope optical limit
  13. GRB 210706A: optical upper limit of Sintesz-Newton/CrAO and AS-32/AbAO
  14. GRB 210706A: GIT optical upper limits
  15. GRB 210704A: OSIRIS/GTC spectroscopy
  16. GRB 210704A: CAHA 2.2m Afterglow Detection
  17. GRB 210704A: RATIR optical upper limits
  18. GRB 210704A: Swift/UVOT Upper Limits
  19. GRB 210619B: ALMA detection
  20. GRB 210704A: TNG detection of the optical afterglow candidate
  21. GRB 210704A: Assy optical afterglow candidate
  22. GRB 210704A: possible local hosts
  23. GRB 210702A: BOOTES-3/YA optical counterpart observations
  24. GRB 210702A: Chilescope optical observations
  25. GRB 210702A: iTelescope optical afterglow observations
  26. GRB 210702A: VLT/X-shooter redshift
  27. GRB210702A: MeerLICHT multi-colour photometry
  28. Swift GRB210702.80: Global MASTER-Net OT detection
  29. GRB 210702A: Swift detection of a burst with a bright optical counterpart
  30. IceCube-210629A: One Candidate Counterpart from the Zwicky Transient Facility
  31. GRB 210626A: CAHA 2.2m telescope optical limit
  32. GRB 210619B: Deep CAHA 2.2m detection and late-time light curve behavior
  33. GRB 210626A: Ondrejov D50 optical limit
  34. GRB 210626A: GIT optical upper limit
  35. GRB 210618A: 1.5m OSN optical upper limit
  36. GRB210619B: optical afterglow detection from Konkoly Observatory
  37. GRB 210610B: T-CAT optical observations
  38. GRB 210619B: Even further SAO RAS optical observations
  39. GRB 210619B: Mini-MegaTORTORA early optical observations
  40. GRB 210619B: Abbey Ridge Observatory optical afterglow observation
  41. GRB 210619B: Further SAO RAS optical observations
  42. GRB 210619B: possibility of lensed visible afterglow?
  43. GRB 210619B: AbAO optical observations
  44. GRB 210619B: NOT optical observations
  45. GRB 210619B: 1.5m OSN optical observation
  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: steepening of the decay observed at the D50
  52. GRB 210619B: Liverpool Telescope First Hour Observations
  53. GRB 210619B: Xinglong TNT optical observations
  54. GRB 210619B: KAIT Optical Detection
  55. GRB 210619B: Liverpool telescope imaging of a red afterglow
  56. GRB 210619B: SARA-KP 0.9m Optical Afterglow Detection
  57. GRB 210619B: iTelescope T18 detection
  58. GRB 210619B: Ondrejov D50 detection
  59. Swift GRB210619.99: Global MASTER-Net OT detection
  60. GRB 210619B: Swift detection of a bright burst and optical counterpart
  61. Swift GRB210619.99: Global MASTER-Net OT detection
  62. GRB 210618A: Swift/UVOT Upper Limits
  63. GRB 210618A: BOOTES-2/TELMA optical upper limit
  64. GRB 210618A: DDOTI upper limit for the optical afterglow
  65. GRB 210610B: Swift/UVOT Detection
  66. GRB 210610A: Swift/UVOT Detection
  67. GRB 210610B: CrAO/ZTSH continued optical observations and light curve
  68. GRB 210610B: AbAO optical observations
  69. GRB 210610B: REM optical/NIR observations of the afterglow
  70. Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
  71. GRB 210610B: iTelescope optical afterglow observations
  72. GRB 210610B: Further SAO RAS optical observations
  73. GRB 210610A: SAO RAS optical observations
  74. GRB 210610B: optical observations from Burke-Gaffney Observatory and Abbey Ridge Observatory
  75. GRB 210610B: Continued KAIT Optical Detection
  76. GRB 210610B: optical photometry of afterglow at INASAN/Simeiz
  77. GRB210610B: SARA-KP 0.9m Optical Afterglow Detection
  78. GRB 210610B: MITSuME Akeno optical observation
  79. GRB 210610B: VLA detection
  80. GRB 210610B: ALMA detection
  81. GRB 210610B: Liverpool Telescope optical photometry
  82. GRB 210610B: CrAO/ZTSH optical observations and light curve
  83. GRB 210610A: CrAO/ZTSH optical observations
  84. GRB 210610B: CrAO/ZTSH optical observations (correction to the GCN circ. 30212)
  85. GRB 210610A: CrAO/ZTSH optical observations
  86. GRB 210610B: Zwicky Transient Facility afterglow detection
  87. GRB 210610B: optical afterglow observations
  88. GRB 210610B: KAIT Optical Detection
  89. GRB 210610A: KAIT Optical Detection
  90. GRB 210610B: University of Siena Observatory optical photometry of the afterglow
  91. GRB 210610B: GOTO confirmation of afterglow detection
  92. GRB 210610A: RATIR Optical and NIR Detection
  93. GRB 210610B: RATIR Optical and NIR Observations
  94. GRB 210610B: Photometry and phot-redshift from Legacy Survey, PanSTAR, and SDSS
  95. GRB 210610B: SAO RAS optical observations
  96. GRB 210610A: 1.5m OSN optical observation
  97. GRB 210610B: correction to GCN 30181
  98. GRB 210610B: NOT optical observations and tentative redshift
  99. GRB 210610B: iTelescope optical afterglow observations
  100. GRB210610B: MeerLICHT multi-colour photometry

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