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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"

32484 results found.

  1. GRB 060505: Swift XRT afterglow canditate position
  2. GRB 060502b: Second epoch Gemini observations
  3. GRB 060428B: spectroscopy
  4. GRB 060502B: optical observations
  5. GRB 060502B: AROMA refined photometric calibration
  6. GRB 060502B MDM Follow-up Observation
  7. GRB 060502b: Gemini imaging and spectroscopy
  8. GRB060502A, optical observation
  9. GRB 060502B: Swift/UVOT upper limits
  10. GRB 060502A: Swift/UVOT source detection
  11. GRB 060429: Refined IPN error box and Konus-Wind spectrum
  12. GRB 060502B: MDM Optical Observation
  13. GRB 060502B: AROMA optical observations
  14. GRB 060502B: Refined analysis of the Swift-BAT short burst
  15. GRB060502B: Swift XRT Team refined analysis
  16. Short GRB 060502B: Tautenburg Observation
  17. GRB 060427B Milagro GeV/TeV Observations
  18. GRB 060502A: TTT Observations
  19. GRB060502B: correction to XRT position
  20. GRB 060501: P60 Observations and Candidate Retraction
  21. GRB 060502B: Xinglong optical observation
  22. GRB060502: Swift-XRT refined analysis
  23. GRB 060502: Swift-BAT refined analysis
  24. GRB060502: Gemini spectroscopy
  25. GRB 060502: APO Spectroscopic Observations
  26. GRB060501: Swift UVOT followup observations
  27. GRB060502: Super-LOTIS Observations
  28. GRB 060502: P60 Afterglow Confirmation
  29. GRB 060501: MDM Observations
  30. GRB060501: Super-LOTIS observations
  31. GRB060501: P60 imaging and afterglow candidate
  32. GRB 060501: Refined analysis of the Swift-BAT burst
  33. GRB 060501: ROTSE-III Optical Limits
  34. Konus-Wind observation of GRB 060427B
  35. GRB060428B - SDSS Pre-Burst Observations
  36. GRB060428B: optical observation
  37. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  38. GRB 060428B: MDM Observations
  39. GRB 060428A: PROMPT Observations
  40. GRB060428B: Swift XRT Team refined analysis
  41. GRB 060428B: Refined analysis of the Swift-BAT burst
  42. GRB 060428B: Xinglong I-band limit
  43. GRB 060428B: KAIT observations
  44. GRB 051117A: Bright host galaxy not confirmed
  45. GRB060428A: Swift/UVOT observations.
  46. GRB060428B, optical observation
  47. GRB 060428A: Refined analysis of the Swift-BAT burst
  48. GRB 060428b : Kiso R-band limit
  49. GRB 060428b: Optical afterglow candidate
  50. GRB060428A: Swift XRT Team refined analysis
  51. GRB 060427: NIR observations
  52. GRB060427: Xinglong optical Observations
  53. GRB 060427: Swift/UVOT upper limits.
  54. GRB 060427: Refined analysis of the Swift-BAT burst
  55. GRB060427: Swift XRT Team refined analysis
  56. GRB060418: Swift XRT Team Further Refined Analysis
  57. GRB 060427, optical observation
  58. GRB060424: optical afterglow detection
  59. GRB060418: Further Analysis of MIKE Spectroscopy
  60. GRB 060424: Refined analysis of the Swift-BAT burst
  61. GRB 060421: TTT Observations
  62. OT 060420: Likely Not a New Cosmic Transient
  63. No OT 060420 in MASCOT images
  64. GRB060421: Swift/UVOT observations
  65. GRB 060421: Swift-BAT Refined Analysis
  66. GRB 060421: Swift-XRT refined analysis
  67. GRB 060418: prediction of t_break
  68. GRB060418: optical observations
  69. Konus-Wind observation of GRB 060418
  70. Possible GRB060421: BART limits
  71. Erratum of GCN 4983 for GRB 060418 IR follow-up
  72. GRB 060418 : IR afterglow observations
  73. GRB 060418 : Lulin Optical follow-up
  74. GRB 060418: JHKs PAIRITEL Observations of Afterglow
  75. GRB 060418: Radio Observations
  76. GRB060418, BVRcIc field calibration
  77. GRB060418: Swift/UVOT Observations
  78. GRB060418: Optical Observations
  79. GRB 060418: FRAM early afterglow observation
  80. GRB 060418: Refined Analysis of the Swift-BAT burst
  81. VLT/UVES observations of GRB060418
  82. GRB 060418, SMARTS continuing afterglow observations
  83. GRB 060418: PROMPT Detections
  84. GRB 060418, SMARTS optical/IR afterglow observations
  85. GRB060418: Magellan/MIKE Spectroscopic Redshift
  86. GRB060418 : LT optical afterglow observation
  87. GRB 060418: REM candidate afterglow
  88. SGR 1900+14: Refined analysis of the Swift-BAT outburst
  89. GRB060413: Swift/UVOT upper limits
  90. GRB 060413: REM NIR Observations
  91. GRB 060413: Refined analysis of the Swift-BAT burst
  92. GRB 060413: Watcher UBVR observations
  93. GRB 060413: XRT refined analysis
  94. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  95. GRB 060413: Swift detection of a burst
  96. GRB060403: optical observations
  97. GRB 060403 Optical observations
  98. GRB 060403: MITSuME optical observation
  99. GRB060403: Optical Limit
  100. GRB060403: XRT refined analysis

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