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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"

36146 results found.

  1. GRB 060501: Refined analysis of the Swift-BAT burst
  2. GRB060501: Swift XRT position
  3. GRB 060501: ROTSE-III Optical Limits
  4. GRB 060501: Swift detection of a burst
  5. IPN triangulation of GRB060429 (short/hard)
  6. Konus-Wind observation of GRB 060427B
  7. GRB060428B - SDSS Pre-Burst Observations
  8. GRB060428B: optical observation
  9. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  10. GRB 060428B: MDM Observations
  11. GRB 060428A: PROMPT Observations
  12. GRB 060427B: MASTER optical observations
  13. GRB 060427B: IPN localization of a short hard burst
  14. GRB 060428B: Refined analysis of the Swift-BAT burst
  15. GRB 060428B: Xinglong I-band limit
  16. GRB 060428B: KAIT observations
  17. GRB060425:MASTER optical limit
  18. GRB 051117A: Bright host galaxy not confirmed
  19. GRB 060428A: Refined analysis of the Swift-BAT burst
  20. GRB 060428b : Kiso R-band limit
  21. GRB060427:MASTER optical limit
  22. GRB 060428b: Optical afterglow candidate
  23. GRB 060428B: Swift detection of a burst
  24. GRB 060427: NIR observations
  25. GRB 060428: Swift detection of a burst
  26. GRB 060427: NOT observations
  27. GRB 060427: Swift/UVOT upper limits.
  28. GRB 060427: Refined analysis of the Swift-BAT burst
  29. GRB060418: Swift XRT Team Further Refined Analysis
  30. GRB060425:MASTER survey observations
  31. GRB 060427, optical observation
  32. GRB 060427: Swift detection of a burst
  33. GRB 060425: IPN localization and KW spectrum of a short, hard burst
  34. An interactive program for GRB pseudo-redshift computations
  35. GRB060424: optical afterglow detection
  36. GRB060418: Further Analysis of MIKE Spectroscopy
  37. GRB 060424: Refined analysis of the Swift-BAT burst
  38. GRB 060424: Swift detection of a burst
  39. GRB 060421: TTT Observations
  40. GRB 060421: Swift-BAT Refined Analysis
  41. GRB 060421: Swift-XRT refined analysis
  42. GRB 060418: prediction of t_break
  43. GRB060418: optical observations
  44. Konus-Wind observation of GRB 060418
  45. GRB(?)060421:MASTER optical limit
  46. GRB(?)060421 : XRT position
  47. GRB(?) 060421: Swift detection of a burst
  48. Erratum of GCN 4983 for GRB 060418 IR follow-up
  49. GRB 060418 : IR afterglow observations
  50. GRB 060418 : Lulin Optical follow-up
  51. GRB 060418: JHKs PAIRITEL Observations of Afterglow
  52. GRB 060418: Radio Observations
  53. GRB060418, BVRcIc field calibration
  54. GRB060418: Optical Observations
  55. GRB 060418: FRAM early afterglow observation
  56. GRB 060418: Refined Analysis of the Swift-BAT burst
  57. GRB060418: Swift XRT Team Refined Analysis
  58. GRB 060418, SMARTS continuing afterglow observations
  59. GRB 060418: PROMPT Detections
  60. GRB 060418, SMARTS optical/IR afterglow observations
  61. GRB060418: Magellan/MIKE Spectroscopic Redshift
  62. GRB060418 : LT optical afterglow observation
  63. GRB 060418: REM candidate afterglow
  64. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  65. GRB 060413: REM NIR Observations
  66. GRB 060413: Refined analysis of the Swift-BAT burst
  67. GRB 060413: Watcher UBVR observations
  68. GRB 060413: XRT refined analysis
  69. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  70. GRB 060413: Swift detection of a burst
  71. GRB060403: optical observations
  72. GRB 060403 Optical observations
  73. GRB 060403: MITSuME optical observation
  74. GRB060403: XRT refined analysis
  75. GRB 060403: Swift/UVOT upper limits
  76. GRB 060403: Refined analysis of the Swift-BAT burst
  77. GRB 060403: Swift detection of a burst
  78. GRB 060322: LNA optical limit
  79. GRB 060218SN 2006aj: optical observations at Rozhen Observatory
  80. GRB 060323 : WIDGET simultaneous optical observations
  81. GRB 060323: Early optical observation at Xinglong
  82. GRB060218, optical observations
  83. GRB 060322: Confirmation of Swift XRT afterglow
  84. GRB 060211A: optical observation
  85. GRB060323: optical limit
  86. GRB060211B: optical observation
  87. GRB060323: NOT optical observations
  88. GRB 060322: IAC80 optical observations
  89. GRB 060322: Swift XRT afterglow candidate
  90. GRB 060323: Swift/UVOT Observations
  91. GRB 060323: optical afterglow confirmed
  92. GRB060323: NOT observations
  93. GRB 060323: Optical Observations
  94. GRB 060323: Tautenburg OT candidate retraction
  95. GRB 060323: Refined analysis of the Swift-BAT burst
  96. GRB 060323: optical observations at TNG
  97. GRB 060323: Swift XRT refined analysis
  98. GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
  99. GRB 060323: Swift/XRT position
  100. GRB 060322: Refined analysis of the Swift-BAT burst

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