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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"

26367 results found.

  1. GRB060428A: Swift/UVOT observations.
  2. GRB060428B, optical observation
  3. GRB 060428A: Refined analysis of the Swift-BAT burst
  4. GRB 060428b : Kiso R-band limit
  5. GRB 060428b: Optical afterglow candidate
  6. GRB060428A: Swift XRT Team refined analysis
  7. GRB 060428B: Swift detection of a burst
  8. GRB 060427: NIR observations
  9. GRB060427: Xinglong optical Observations
  10. GRB 060428: Swift detection of a burst
  11. GRB 060427: Swift/UVOT upper limits.
  12. GRB 060427: Refined analysis of the Swift-BAT burst
  13. GRB060427: Swift XRT Team refined analysis
  14. GRB060418: Swift XRT Team Further Refined Analysis
  15. GRB060425:MASTER survey observations
  16. GRB 060427, optical observation
  17. GRB 060427: Swift detection of a burst
  18. GRB060418: Further Analysis of MIKE Spectroscopy
  19. GRB 060424: Refined analysis of the Swift-BAT burst
  20. GRB 060421: TTT Observations
  21. GRB060421: Swift/UVOT observations
  22. GRB 060421: Swift-BAT Refined Analysis
  23. GRB 060421: Swift-XRT refined analysis
  24. GRB 060418: prediction of t_break
  25. GRB(?) 060421: Swift detection of a burst
  26. Erratum of GCN 4983 for GRB 060418 IR follow-up
  27. GRB 060418 : IR afterglow observations
  28. GRB 060418: Radio Observations
  29. GRB060418, BVRcIc field calibration
  30. GRB060418: Swift/UVOT Observations
  31. GRB060418: Optical Observations
  32. GRB 060418: Refined Analysis of the Swift-BAT burst
  33. GRB 060418, SMARTS continuing afterglow observations
  34. GRB 060418, SMARTS optical/IR afterglow observations
  35. GRB060418 : LT optical afterglow observation
  36. GRB 060418: REM candidate afterglow
  37. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  38. GRB060413: Swift/UVOT upper limits
  39. GRB 060413: REM NIR Observations
  40. GRB 060413: Refined analysis of the Swift-BAT burst
  41. GRB 060403: MITSuME optical observation
  42. GRB060403: Optical Limit
  43. GRB060403: XRT refined analysis
  44. GRB 060403: Swift/UVOT upper limits
  45. SGR 1900+14: BAT observations
  46. GRB 060403: Refined analysis of the Swift-BAT burst
  47. Konus-Wind observation of the recent SGR 1900+14 activity. Will
  48. GRB 060403: Swift detection of a burst
  49. HETE trigger H4044: RTT150 optical observations
  50. GRB060331: Swift/UVOT upper limits
  51. Swift XRT observations of the HETE transient H4043
  52. H4043, an unusual high-energy transient observed by HETE
  53. GRB 060322: LNA optical limit
  54. SGR 1900+14: bright burst detected by Konus-Wind on March 28
  55. INTEGRAL and XMM ToO observations of SGR1900+14
  56. SGR 1900+14: Swift-BAT detection of a bright outburst
  57. GRB 060323 : WIDGET simultaneous optical observations
  58. GRB 060323: Early optical observation at Xinglong
  59. GRB 060322: Confirmation of Swift XRT afterglow
  60. GRB060323: NOT optical observations
  61. GRB 060322: IAC80 optical observations
  62. GRB 060322: Swift XRT afterglow candidate
  63. GRB060323: P60 Observations
  64. GRB 060323: Swift/UVOT Observations
  65. GRB 060323: optical afterglow confirmed
  66. GRB060323: NOT observations
  67. GRB 060323: Optical Observations
  68. GRB 060323: Refined analysis of the Swift-BAT burst
  69. GRB 060323: optical observations at TNG
  70. GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
  71. GRB 060322: Refined analysis of the Swift-BAT burst
  72. GRB060323, optical observation
  73. GRB060323 - SDSS Pre-Burst Observations
  74. GRB 060323: Swift detection of a burst with a possible optical afterglow
  75. GRB 060322: Swift-BAT detection of a 200-sec burst
  76. GRB 060218/SN 2006aj, LNA optical observation
  77. GRB060218: Refined photometric calibration of comparison stars
  78. GRB 060319: WHT K-band candidate afterglow
  79. GRB060319: Swift/UVOT upper limits
  80. GRB 060319: Swift-BAT refined analysis
  81. GRB 060319 optical observations at TNG
  82. GRB060319 : Liverpool Telescope optical limit
  83. GRB060319 - SDSS Pre-burst Observations
  84. GRB060313: Radio Observations
  85. GRB 060313: early afterglow NIR upper limits with REM
  86. GRB 060313: Further analysis of the Swift-BAT bright short hard burst
  87. GRB 060313: Swift/UVOT Observations
  88. GRB 060313: Refined analysis of the Swift-BAT bright short hard burst
  89. GRB 060313, SMARTS optical counterpart?
  90. GRB 060313, SMARTS optical/IR observations
  91. GRB060313: optical and near infrared observations with REM
  92. GRB060218: SARA Observations of SN2006aj
  93. GRB 060312: Refined analysis of the Swift-BAT burst
  94. GRB 060218/SN 2006aj, high resolution spectra
  95. GRB 060312: Swift XRT team refined analysis
  96. GRB060306: APO Ks-band Imaging Observations
  97. GRB 060312: ROTSE-III Optical Limits
  98. Bright short hard GRB 060303: IPN localization and Konus spectrum
  99. GRB060219: Liverpool Telescope observations
  100. GRB 060306: MAGNUM observations

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