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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"

35954 results found.

  1. Short GRB 060502B: Tautenburg Observation
  2. GRB 060427B Milagro GeV/TeV Observations
  3. GRB 060502A: TTT Observations
  4. GRB 060501: P60 Observations and Candidate Retraction
  5. GRB 060502B: Xinglong optical observation
  6. GRB 060502B: MASTER optical observations
  7. GRB 060502B: Swift detection of a short burst
  8. GRB 060502: Swift-BAT refined analysis
  9. GRB060502: Gemini spectroscopy
  10. GRB 060502: APO Spectroscopic Observations
  11. GRB 060502: P60 Afterglow Confirmation
  12. GRB 060502: Swift detection of a burst with an optical counterpart
  13. GRB 060501: MDM Observations
  14. GRB060501: Super-LOTIS observations
  15. GRB 060501: Refined analysis of the Swift-BAT burst
  16. GRB060501: Swift XRT position
  17. GRB 060501: ROTSE-III Optical Limits
  18. GRB 060501: Swift detection of a burst
  19. IPN triangulation of GRB060429 (short/hard)
  20. Konus-Wind observation of GRB 060427B
  21. GRB060428B - SDSS Pre-Burst Observations
  22. GRB060428B: optical observation
  23. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  24. GRB 060428B: MDM Observations
  25. GRB 060428A: PROMPT Observations
  26. GRB 060427B: MASTER optical observations
  27. GRB 060427B: IPN localization of a short hard burst
  28. GRB 060428B: Refined analysis of the Swift-BAT burst
  29. GRB 060428B: Xinglong I-band limit
  30. GRB 060428B: KAIT observations
  31. GRB060425:MASTER optical limit
  32. GRB 051117A: Bright host galaxy not confirmed
  33. GRB 060428A: Refined analysis of the Swift-BAT burst
  34. GRB 060428b : Kiso R-band limit
  35. GRB060427:MASTER optical limit
  36. GRB 060428b: Optical afterglow candidate
  37. GRB 060428B: Swift detection of a burst
  38. GRB 060427: NIR observations
  39. GRB 060428: Swift detection of a burst
  40. GRB 060427: NOT observations
  41. GRB 060427: Swift/UVOT upper limits.
  42. GRB 060427: Refined analysis of the Swift-BAT burst
  43. GRB060418: Swift XRT Team Further Refined Analysis
  44. GRB060425:MASTER survey observations
  45. GRB 060427, optical observation
  46. GRB 060427: Swift detection of a burst
  47. GRB 060425: IPN localization and KW spectrum of a short, hard burst
  48. An interactive program for GRB pseudo-redshift computations
  49. GRB060424: optical afterglow detection
  50. GRB060418: Further Analysis of MIKE Spectroscopy
  51. GRB 060424: Refined analysis of the Swift-BAT burst
  52. GRB 060424: Swift detection of a burst
  53. GRB 060421: TTT Observations
  54. GRB 060421: Swift-BAT Refined Analysis
  55. GRB 060421: Swift-XRT refined analysis
  56. GRB 060418: prediction of t_break
  57. GRB060418: optical observations
  58. Konus-Wind observation of GRB 060418
  59. GRB(?)060421:MASTER optical limit
  60. GRB(?)060421 : XRT position
  61. GRB(?) 060421: Swift detection of a burst
  62. Erratum of GCN 4983 for GRB 060418 IR follow-up
  63. GRB 060418 : IR afterglow observations
  64. GRB 060418 : Lulin Optical follow-up
  65. GRB 060418: JHKs PAIRITEL Observations of Afterglow
  66. GRB 060418: Radio Observations
  67. GRB060418, BVRcIc field calibration
  68. GRB060418: Optical Observations
  69. GRB 060418: FRAM early afterglow observation
  70. GRB 060418: Refined Analysis of the Swift-BAT burst
  71. GRB060418: Swift XRT Team Refined Analysis
  72. GRB 060418, SMARTS continuing afterglow observations
  73. GRB 060418: PROMPT Detections
  74. GRB 060418, SMARTS optical/IR afterglow observations
  75. GRB060418: Magellan/MIKE Spectroscopic Redshift
  76. GRB060418 : LT optical afterglow observation
  77. GRB 060418: REM candidate afterglow
  78. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  79. GRB 060413: REM NIR Observations
  80. GRB 060413: Refined analysis of the Swift-BAT burst
  81. GRB 060413: Watcher UBVR observations
  82. GRB 060413: XRT refined analysis
  83. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  84. GRB 060413: Swift detection of a burst
  85. GRB060403: optical observations
  86. GRB 060403 Optical observations
  87. GRB 060403: MITSuME optical observation
  88. GRB060403: XRT refined analysis
  89. GRB 060403: Swift/UVOT upper limits
  90. GRB 060403: Refined analysis of the Swift-BAT burst
  91. GRB 060403: Swift detection of a burst
  92. GRB 060322: LNA optical limit
  93. GRB 060218SN 2006aj: optical observations at Rozhen Observatory
  94. GRB 060323 : WIDGET simultaneous optical observations
  95. GRB 060323: Early optical observation at Xinglong
  96. GRB060218, optical observations
  97. GRB 060322: Confirmation of Swift XRT afterglow
  98. GRB 060211A: optical observation
  99. GRB060323: optical limit
  100. GRB060211B: optical observation

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