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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"

25014 results found.

  1. GRB 060510B: Swift-BAT Refined Analysis
  2. GRB060510A: XRT refined analysis
  3. GRB060510 - SDSS Pre-Burst Observations
  4. GRB 060510B: Swift detection of a burst
  5. GRB 060510: Swift detection of a burst with optical transient
  6. GRB060507: optical afterglow detection
  7. GRB060502B: improvement in the XRT afterglow position
  8. GRB 060507: Final Refined analysis of the Swift-BAT burst
  9. GRB 060507: Swift-BAT Refined Analysis
  10. GRB 060505: PROMPT Observations
  11. GRB 060507: Swift XRT Team Refined Analysis
  12. GRB 060507: Swift detection of a burst
  13. GRB 060429: Suzaku WAM observation
  14. GRB060505: Swift/UVOT Observations
  15. GRB060425: new MASTER survey method
  16. GRB 060306: Further Analysis of SOAR and APO NIR Observations
  17. GRB 060505: Swift XRT afterglow canditate position
  18. GRB 060502b: Second epoch Gemini observations
  19. GRB 060505: Swift-BAT detection of a weak burst
  20. GRB 060428B: spectroscopy
  21. GRB 060502B: optical observations
  22. GRB 060502B: AROMA refined photometric calibration
  23. GRB 060502B MDM Follow-up Observation
  24. GRB 060502b: Gemini imaging and spectroscopy
  25. GRB060502A, optical observation
  26. GRB 060502B: Swift/UVOT upper limits
  27. GRB 060502A: Swift/UVOT source detection
  28. GRB 060502B: MDM Optical Observation
  29. GRB 060502B: Refined analysis of the Swift-BAT short burst
  30. GRB060502B: Swift XRT Team refined analysis
  31. GRB 060501: P60 Observations and Candidate Retraction
  32. GRB 060502B: Xinglong optical observation
  33. GRB060502: Swift-XRT refined analysis
  34. GRB 060502: Swift-BAT refined analysis
  35. GRB060501: Swift UVOT followup observations
  36. GRB 060502: P60 Afterglow Confirmation
  37. GRB 060502: Swift detection of a burst with an optical counterpart
  38. GRB060501: P60 imaging and afterglow candidate
  39. GRB 060501: Refined analysis of the Swift-BAT burst
  40. GRB060428B - SDSS Pre-Burst Observations
  41. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  42. GRB 060428B: MDM Observations
  43. GRB060428B: Swift XRT Team refined analysis
  44. GRB 060427B: IPN localization of a short hard burst
  45. GRB 060428B: Refined analysis of the Swift-BAT burst
  46. GRB 060428B: Xinglong I-band limit
  47. GRB 051117A: Bright host galaxy not confirmed
  48. GRB060428A: Swift/UVOT observations.
  49. GRB060428B, optical observation
  50. GRB 060428A: Refined analysis of the Swift-BAT burst
  51. GRB 060428b : Kiso R-band limit
  52. GRB 060428b: Optical afterglow candidate
  53. GRB060428A: Swift XRT Team refined analysis
  54. GRB 060428B: Swift detection of a burst
  55. GRB 060427: NIR observations
  56. GRB060427: Xinglong optical Observations
  57. GRB 060428: Swift detection of a burst
  58. GRB 060427: Swift/UVOT upper limits.
  59. GRB 060427: Refined analysis of the Swift-BAT burst
  60. GRB060427: Swift XRT Team refined analysis
  61. GRB060418: Swift XRT Team Further Refined Analysis
  62. GRB060425:MASTER survey observations
  63. GRB 060427, optical observation
  64. GRB 060427: Swift detection of a burst
  65. GRB060418: Further Analysis of MIKE Spectroscopy
  66. GRB 060424: Refined analysis of the Swift-BAT burst
  67. GRB 060421: TTT Observations
  68. GRB060421: Swift/UVOT observations
  69. GRB 060421: Swift-BAT Refined Analysis
  70. GRB 060421: Swift-XRT refined analysis
  71. GRB 060418: prediction of t_break
  72. GRB(?) 060421: Swift detection of a burst
  73. Erratum of GCN 4983 for GRB 060418 IR follow-up
  74. GRB 060418 : IR afterglow observations
  75. GRB 060418: Radio Observations
  76. GRB060418, BVRcIc field calibration
  77. GRB060418: Swift/UVOT Observations
  78. GRB060418: Optical Observations
  79. GRB 060418: Refined Analysis of the Swift-BAT burst
  80. GRB 060418, SMARTS continuing afterglow observations
  81. GRB 060418, SMARTS optical/IR afterglow observations
  82. GRB060418 : LT optical afterglow observation
  83. GRB 060418: REM candidate afterglow
  84. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  85. GRB060413: Swift/UVOT upper limits
  86. GRB 060413: REM NIR Observations
  87. GRB 060413: Refined analysis of the Swift-BAT burst
  88. GRB 060403: MITSuME optical observation
  89. GRB060403: Optical Limit
  90. GRB060403: XRT refined analysis
  91. GRB 060403: Swift/UVOT upper limits
  92. SGR 1900+14: BAT observations
  93. GRB 060403: Refined analysis of the Swift-BAT burst
  94. Konus-Wind observation of the recent SGR 1900+14 activity. Will
  95. GRB 060403: Swift detection of a burst
  96. HETE trigger H4044: RTT150 optical observations
  97. GRB060331: Swift/UVOT upper limits
  98. Swift XRT observations of the HETE transient H4043
  99. H4043, an unusual high-energy transient observed by HETE
  100. GRB 060322: LNA optical limit

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