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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"

36149 results found.

  1. GRB 060502: Swift detection of a burst with an optical counterpart
  2. GRB 060501: MDM Observations
  3. GRB060501: Super-LOTIS observations
  4. GRB 060501: Refined analysis of the Swift-BAT burst
  5. GRB060501: Swift XRT position
  6. GRB 060501: ROTSE-III Optical Limits
  7. GRB 060501: Swift detection of a burst
  8. IPN triangulation of GRB060429 (short/hard)
  9. Konus-Wind observation of GRB 060427B
  10. GRB060428B - SDSS Pre-Burst Observations
  11. GRB060428B: optical observation
  12. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  13. GRB 060428B: MDM Observations
  14. GRB 060428A: PROMPT Observations
  15. GRB 060427B: MASTER optical observations
  16. GRB 060427B: IPN localization of a short hard burst
  17. GRB 060428B: Refined analysis of the Swift-BAT burst
  18. GRB 060428B: Xinglong I-band limit
  19. GRB 060428B: KAIT observations
  20. GRB060425:MASTER optical limit
  21. GRB 051117A: Bright host galaxy not confirmed
  22. GRB 060428A: Refined analysis of the Swift-BAT burst
  23. GRB 060428b : Kiso R-band limit
  24. GRB060427:MASTER optical limit
  25. GRB 060428b: Optical afterglow candidate
  26. GRB 060428B: Swift detection of a burst
  27. GRB 060427: NIR observations
  28. GRB 060428: Swift detection of a burst
  29. GRB 060427: NOT observations
  30. GRB 060427: Swift/UVOT upper limits.
  31. GRB 060427: Refined analysis of the Swift-BAT burst
  32. GRB060418: Swift XRT Team Further Refined Analysis
  33. GRB060425:MASTER survey observations
  34. GRB 060427, optical observation
  35. GRB 060427: Swift detection of a burst
  36. GRB 060425: IPN localization and KW spectrum of a short, hard burst
  37. An interactive program for GRB pseudo-redshift computations
  38. GRB060424: optical afterglow detection
  39. GRB060418: Further Analysis of MIKE Spectroscopy
  40. GRB 060424: Refined analysis of the Swift-BAT burst
  41. GRB 060424: Swift detection of a burst
  42. GRB 060421: TTT Observations
  43. GRB 060421: Swift-BAT Refined Analysis
  44. GRB 060421: Swift-XRT refined analysis
  45. GRB 060418: prediction of t_break
  46. GRB060418: optical observations
  47. Konus-Wind observation of GRB 060418
  48. GRB(?)060421:MASTER optical limit
  49. GRB(?)060421 : XRT position
  50. GRB(?) 060421: Swift detection of a burst
  51. Erratum of GCN 4983 for GRB 060418 IR follow-up
  52. GRB 060418 : IR afterglow observations
  53. GRB 060418 : Lulin Optical follow-up
  54. GRB 060418: JHKs PAIRITEL Observations of Afterglow
  55. GRB 060418: Radio Observations
  56. GRB060418, BVRcIc field calibration
  57. GRB060418: Optical Observations
  58. GRB 060418: FRAM early afterglow observation
  59. GRB 060418: Refined Analysis of the Swift-BAT burst
  60. GRB060418: Swift XRT Team Refined Analysis
  61. GRB 060418, SMARTS continuing afterglow observations
  62. GRB 060418: PROMPT Detections
  63. GRB 060418, SMARTS optical/IR afterglow observations
  64. GRB060418: Magellan/MIKE Spectroscopic Redshift
  65. GRB060418 : LT optical afterglow observation
  66. GRB 060418: REM candidate afterglow
  67. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  68. GRB 060413: REM NIR Observations
  69. GRB 060413: Refined analysis of the Swift-BAT burst
  70. GRB 060413: Watcher UBVR observations
  71. GRB 060413: XRT refined analysis
  72. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  73. GRB 060413: Swift detection of a burst
  74. GRB060403: optical observations
  75. GRB 060403 Optical observations
  76. GRB 060403: MITSuME optical observation
  77. GRB060403: XRT refined analysis
  78. GRB 060403: Swift/UVOT upper limits
  79. GRB 060403: Refined analysis of the Swift-BAT burst
  80. GRB 060403: Swift detection of a burst
  81. GRB 060322: LNA optical limit
  82. GRB 060218SN 2006aj: optical observations at Rozhen Observatory
  83. GRB 060323 : WIDGET simultaneous optical observations
  84. GRB 060323: Early optical observation at Xinglong
  85. GRB060218, optical observations
  86. GRB 060322: Confirmation of Swift XRT afterglow
  87. GRB 060211A: optical observation
  88. GRB060323: optical limit
  89. GRB060211B: optical observation
  90. GRB060323: NOT optical observations
  91. GRB 060322: IAC80 optical observations
  92. GRB 060322: Swift XRT afterglow candidate
  93. GRB 060323: Swift/UVOT Observations
  94. GRB 060323: optical afterglow confirmed
  95. GRB060323: NOT observations
  96. GRB 060323: Optical Observations
  97. GRB 060323: Tautenburg OT candidate retraction
  98. GRB 060323: Refined analysis of the Swift-BAT burst
  99. GRB 060323: optical observations at TNG
  100. GRB 060323: Swift XRT refined analysis

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