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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

7406 results found.

  1. GRB 060607: Swift detection of a burst with bright optical counterpart
  2. GRB060605: Spectral Observations and Redshift
  3. GRB 060605: Swift detection of a burst with optical counterpart
  4. GRB060604: Swift/UVOT detections
  5. GRB 060604: redshift
  6. GRB 060604: Swift detection of a burst with possible optical counterpart
  7. GRB 060602B: Swift detection of a burst
  8. GRB060602B: Watcher observations - no OT candidate
  9. GRB060602B: BOOTES-IR candidate afterglow
  10. GRB 060526: Continued emission for the Swift burst
  11. GRB 060526: Swift detection of a burst with x-ray and optical afterglow
  12. GRB 060522: REM NIR observations
  13. GRB 060522: TNG optical observations
  14. GRB 060515: Swift/XRT Team refined analysis
  15. GRB 060515: Super-LOTIS Observations
  16. GRB060515: Swift/UVOT initial observation
  17. GRB 060515: TAROT optical observation
  18. GRB 060512: 1.54m Kuiper Observations
  19. GRB 060505 - OT candidate + galaxy spectrum
  20. GRB 060512: Swift detection of a burst with an optical afterglow
  21. GRB060510B : Faulkes North Telescope detection
  22. GRB 060510b: Gemini NIR observations
  23. GRB 060510b: NIR observations
  24. GRB 060510B: MDM Observations and candidate OT
  25. GRB 060510B: Swift detection of a burst
  26. GRB060502B: improvement in the XRT afterglow position
  27. GRB 060507: Swift/UVOT Upper Limits
  28. GRB 060507: MDM Optical Upper Limit
  29. GRB 060505: Swift XRT Team Refined Analysis
  30. GRB060425: new MASTER survey method
  31. GRB 060502B MDM Follow-up Observation
  32. GRB060502B: correction to XRT position
  33. GRB 060501: P60 Observations and Candidate Retraction
  34. GRB 060502B: MASTER optical observations
  35. GRB 060502: P60 Afterglow Confirmation
  36. GRB 060501: MDM Observations
  37. GRB060501: Super-LOTIS observations
  38. GRB060501: P60 imaging and afterglow candidate
  39. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  40. GRB060428B: Swift XRT Team refined analysis
  41. GRB 060428B: Xinglong I-band limit
  42. GRB 060428B: KAIT observations
  43. GRB060428A: Swift/UVOT observations.
  44. GRB 060428b : Kiso R-band limit
  45. GRB060427:MASTER optical limit
  46. GRB 060428b: Optical afterglow candidate
  47. GRB 060428B: Swift detection of a burst
  48. GRB 060427: NIR observations
  49. GRB 060428: Swift detection of a burst
  50. GRB 060427: Swift/UVOT upper limits.
  51. GRB060425:MASTER survey observations
  52. GRB 060427: Swift detection of a burst
  53. OT 060420: Likely Not a New Cosmic Transient
  54. OT 060420: CONCAM detection of a candidate new magnitude 5 optical
  55. GRB060421: Swift/UVOT observations
  56. GRB(?)060421:MASTER optical limit
  57. GRB(?) 060421: Swift detection of a burst
  58. GRB 060418, SMARTS optical/IR afterglow observations
  59. GRB060418 : LT optical afterglow observation
  60. GRB 060418: REM candidate afterglow
  61. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  62. GRB060413: Swift/UVOT upper limits
  63. SGR 1900+14: Swift detection of an outburst
  64. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  65. GRB 060403: Swift detection of a burst
  66. H4043, an unusual high-energy transient observed by HETE
  67. GRB 060322: Confirmation of Swift XRT afterglow
  68. GRB060323: NOT optical observations
  69. GRB 060322: Swift XRT afterglow candidate
  70. GRB 060323: optical afterglow confirmed
  71. GRB 060323: Optical Observations
  72. GRB 060323: Tautenburg OT candidate retraction
  73. GRB 060323: optical observations at TNG
  74. GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
  75. GRB 060323: Swift/XRT position
  76. GRB 060319: WHT K-band candidate afterglow
  77. GRB060319 : Liverpool Telescope optical limit
  78. GRB060319: MASTER optical observation
  79. GRB 060319: Swift detection of a burst
  80. GRB 060313: early afterglow NIR upper limits with REM
  81. GRB060313: SSO 40inch Observations
  82. GRB 060313: PROMPT Observations
  83. GRB060313:Gemini South Observations
  84. GRB060313: optical observations of the afterglow candidate
  85. GRB 060313: Swift-BAT detection of a bright short hard burst
  86. GRB060312: Swift UVOT observation
  87. GRB 060306: Swift detection of a bright burst
  88. GRB 060223B: Swift XRT possible afterglow
  89. GRB 060223: Swift detection of a burst
  90. GRB060218: Radio Afterglow Discovery
  91. GRB 060219: Swift-BAT detection of a weak burst
  92. Brightening of the Optical Counterpart of the Possible GRB 060218
  93. GRB 060218: MDM Observations
  94. GRB 060218: Pre-burst detection of a possible host galaxy
  95. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  96. GRB 060218: Swift-BAT detection of a possible burst
  97. GRB 060213: optical afterglow not confirmed
  98. Swift UVOT observations of GRB060213
  99. GRB 060213: optical afterglow candidate
  100. GRB060213: Swift XRT observations and possible afterglow candidate

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