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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"

21770 results found.

  1. GRB 060510: Swift detection of a burst with optical transient
  2. GRB060507: optical afterglow detection
  3. GRB060502B: improvement in the XRT afterglow position
  4. GRB 060507: Swift-BAT Refined Analysis
  5. GRB 060505: PROMPT Observations
  6. GRB 060507: Swift/UVOT Upper Limits
  7. GRB 060507: Swift XRT Team Refined Analysis
  8. GRB 060429: Suzaku WAM observation
  9. GRB060505: Swift/UVOT Observations
  10. GRB060425: new MASTER survey method
  11. GRB 060505: Swift XRT afterglow canditate position
  12. GRB 060502b: Second epoch Gemini observations
  13. GRB 060428B: spectroscopy
  14. GRB 060502B: optical observations
  15. GRB 060502B: AROMA refined photometric calibration
  16. GRB 060502B MDM Follow-up Observation
  17. GRB 060502b: Gemini imaging and spectroscopy
  18. GRB060502A, optical observation
  19. GRB 060502B: Swift/UVOT upper limits
  20. GRB 060502A: Swift/UVOT source detection
  21. GRB 060429: Refined IPN error box and Konus-Wind spectrum
  22. GRB060502B: Swift XRT Team refined analysis
  23. GRB 060501: P60 Observations and Candidate Retraction
  24. GRB 060502B: Xinglong optical observation
  25. GRB 060502B: MASTER optical observations
  26. GRB 060502: Swift-BAT refined analysis
  27. GRB060501: Swift UVOT followup observations
  28. GRB060502: Super-LOTIS Observations
  29. GRB 060502: P60 Afterglow Confirmation
  30. GRB 060502: Swift detection of a burst with an optical counterpart
  31. GRB060501: P60 imaging and afterglow candidate
  32. GRB 060501: Swift detection of a burst
  33. Konus-Wind observation of GRB 060427B
  34. GRB060428B - SDSS Pre-Burst Observations
  35. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  36. GRB060428B: Swift XRT Team refined analysis
  37. GRB 060427B: IPN localization of a short hard burst
  38. GRB 060428B: Xinglong I-band limit
  39. GRB 051117A: Bright host galaxy not confirmed
  40. GRB060428A: Swift/UVOT observations.
  41. GRB060428B, optical observation
  42. GRB 060428A: Refined analysis of the Swift-BAT burst
  43. GRB 060428b : Kiso R-band limit
  44. GRB 060428b: Optical afterglow candidate
  45. GRB 060428B: Swift detection of a burst
  46. GRB 060427: NIR observations
  47. GRB060427: Xinglong optical Observations
  48. GRB 060428: Swift detection of a burst
  49. GRB 060427: Swift/UVOT upper limits.
  50. GRB 060427: Refined analysis of the Swift-BAT burst
  51. GRB 060427, optical observation
  52. GRB 060427: Swift detection of a burst
  53. GRB 060425: IPN localization and KW spectrum of a short, hard burst
  54. GRB 060424: Refined analysis of the Swift-BAT burst
  55. GRB 060424: Swift detection of a burst
  56. GRB 060421: TTT Observations
  57. OT 060420: CONCAM detection of a candidate new magnitude 5 optical
  58. GRB060421: Swift/UVOT observations
  59. Konus-Wind observation of GRB 060418
  60. GRB(?) 060421: Swift detection of a burst
  61. GRB 060418: Radio Observations
  62. GRB060418, BVRcIc field calibration
  63. GRB060418: Swift/UVOT Observations
  64. GRB060418: Optical Observations
  65. GRB 060418: FRAM early afterglow observation
  66. VLT/UVES observations of GRB060418
  67. GRB 060418: PROMPT Detections
  68. GRB060418 : LT optical afterglow observation
  69. GRB 060418: REM candidate afterglow
  70. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  71. GRB060413: Swift/UVOT upper limits
  72. GRB 060413: REM NIR Observations
  73. GRB 060413: Swift detection of a burst
  74. GRB 060403 Optical observations
  75. GRB 060403: MITSuME optical observation
  76. GRB060403: Optical Limit
  77. GRB 060403: Swift/UVOT upper limits
  78. SGR 1900+14: BAT observations
  79. Konus-Wind observation of the recent SGR 1900+14 activity. Will
  80. GRB 060403: Swift detection of a burst
  81. HETE trigger H4044: RTT150 optical observations
  82. GRB060331: Swift/UVOT upper limits
  83. Swift XRT observations of the HETE transient H4043
  84. HETE Trigger 4043: ROTSE-III Optical Limits
  85. H4043, an unusual high-energy transient observed by HETE
  86. GRB 060322: LNA optical limit
  87. SGR 1900+14: bright burst detected by Konus-Wind on March 28
  88. GRB 060323 : WIDGET simultaneous optical observations
  89. GRB 060323: Early optical observation at Xinglong
  90. GRB 060322: Confirmation of Swift XRT afterglow
  91. SGR 1900+14: Refined Swift-BAT analysis of the renewed activity
  92. GRB060323: NOT optical observations
  93. GRB 060322: IAC80 optical observations
  94. GRB 060322: Swift XRT afterglow candidate
  95. GRB060323: P60 Observations
  96. GRB 060323: Swift/UVOT Observations
  97. GRB 060323: optical afterglow confirmed
  98. GRB060323: NOT observations
  99. GRB 060323: Optical Observations
  100. GRB 060323: Refined analysis of the Swift-BAT burst

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