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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

45652 results found.

  1. GRB 060427B Milagro GeV/TeV Observations
  2. GRB 060502A: TTT Observations
  3. GRB060502B: correction to XRT position
  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. GRB060502: Swift-XRT refined analysis
  9. GRB 060502: Swift-BAT refined analysis
  10. GRB060502: Gemini spectroscopy
  11. GRB 060502: APO Spectroscopic Observations
  12. GRB060501: Swift UVOT followup observations
  13. GRB060502: Super-LOTIS Observations
  14. GRB 060502: P60 Afterglow Confirmation
  15. GRB 060502: Swift detection of a burst with an optical counterpart
  16. GRB 060501: MDM Observations
  17. GRB060501: Super-LOTIS observations
  18. GRB060501: P60 imaging and afterglow candidate
  19. GRB 060501: Refined analysis of the Swift-BAT burst
  20. GRB060501: Swift XRT position
  21. GRB 060501: ROTSE-III Optical Limits
  22. GRB 060501: Swift detection of a burst
  23. IPN triangulation of GRB060429 (short/hard)
  24. Konus-Wind observation of GRB 060427B
  25. GRB060428B - SDSS Pre-Burst Observations
  26. GRB060428B: optical observation
  27. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  28. GRB 060428B: MDM Observations
  29. GRB 060428A: PROMPT Observations
  30. GRB 060427B: MASTER optical observations
  31. GRB060428B: Swift XRT Team refined analysis
  32. GRB 060427B: IPN localization of a short hard burst
  33. GRB 060428B: Refined analysis of the Swift-BAT burst
  34. GRB 060428B: Xinglong I-band limit
  35. GRB 060428B: KAIT observations
  36. GRB060425:MASTER optical limit
  37. GRB 051117A: Bright host galaxy not confirmed
  38. GRB060428A: Swift/UVOT observations.
  39. GRB060428B, optical observation
  40. GRB 060428A: Refined analysis of the Swift-BAT burst
  41. GRB 060428b : Kiso R-band limit
  42. GRB060427:MASTER optical limit
  43. GRB 060428b: Optical afterglow candidate
  44. GRB060428A: Swift XRT Team refined analysis
  45. GRB 060428B: Swift detection of a burst
  46. GRB 060427: NIR observations
  47. GRB060427: Xinglong optical Observations
  48. GRB 060428: Swift detection of a burst
  49. GRB 060427: NOT observations
  50. GRB 060427: Swift/UVOT upper limits.
  51. GRB 060427: Refined analysis of the Swift-BAT burst
  52. GRB060427: Swift XRT Team refined analysis
  53. GRB060418: Swift XRT Team Further Refined Analysis
  54. GRB060425:MASTER survey observations
  55. GRB 060427, optical observation
  56. GRB 060427: Swift detection of a burst
  57. GRB 060425: IPN localization and KW spectrum of a short, hard burst
  58. An interactive program for GRB pseudo-redshift computations
  59. GRB060424: optical afterglow detection
  60. GRB060418: Further Analysis of MIKE Spectroscopy
  61. GRB 060424: Refined analysis of the Swift-BAT burst
  62. GRB 060424: Swift detection of a burst
  63. GRB 060421: TTT Observations
  64. OT 060420: Likely Not a New Cosmic Transient
  65. No OT 060420 in MASCOT images
  66. Swift-BAT detection of Mrk 421
  67. OT 060420: CONCAM detection of a candidate new magnitude 5 optical
  68. GRB060421: Swift/UVOT observations
  69. GRB 060421: Swift-BAT Refined Analysis
  70. GRB 060421: Swift-XRT refined analysis
  71. GRB 060418: prediction of t_break
  72. GRB060418: optical observations
  73. Konus-Wind observation of GRB 060418
  74. GRB(?)060421:MASTER optical limit
  75. GRB(?)060421 : XRT position
  76. Possible GRB060421: BART limits
  77. GRB(?) 060421: Swift detection of a burst
  78. Erratum of GCN 4983 for GRB 060418 IR follow-up
  79. GRB 060418 : IR afterglow observations
  80. GRB 060418 : Lulin Optical follow-up
  81. GRB 060418: JHKs PAIRITEL Observations of Afterglow
  82. GRB 060418: Radio Observations
  83. GRB060418, BVRcIc field calibration
  84. GRB060418: Swift/UVOT Observations
  85. GRB060418: Optical Observations
  86. GRB 060418: FRAM early afterglow observation
  87. GRB 060418: Refined Analysis of the Swift-BAT burst
  88. VLT/UVES observations of GRB060418
  89. GRB060418: Swift XRT Team Refined Analysis
  90. GRB 060418, SMARTS continuing afterglow observations
  91. GRB 060418: PROMPT Detections
  92. GRB 060418, SMARTS optical/IR afterglow observations
  93. GRB060418: Magellan/MIKE Spectroscopic Redshift
  94. GRB060418 : LT optical afterglow observation
  95. GRB 060418: REM candidate afterglow
  96. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  97. SGR 1900+14: Refined analysis of the Swift-BAT outburst
  98. GRB060413: Swift/UVOT upper limits
  99. GRB 060413: REM NIR Observations
  100. SGR 1900+14: Swift detection of an outburst

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