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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"

36154 results found.

  1. XRF 050509c optical afterglow
  2. GRB 050509B and short GRB-SN association? (corrected)
  3. GRB 050509B and short GRB-SN association?
  4. GRB 050509B: Subaru Optical Observations
  5. GRB050502b: Early Observation
  6. GRB050509b, Bok telescope B-band imaging
  7. Refined Chandra analysis of GRB 050509b
  8. GRB050509b, SDSS pre-burst observations
  9. GRB 050509b: Keck/Chandra Cross-Correlation
  10. GRB 050509b: Keck/Chandra Cross-Correlation
  11. Chandra observation of GRB 050509b
  12. GRB 050509b: RAPTOR deep, early limits.
  13. GRB050509B: Optical/Infared observations
  14. GRB 050509b: Swift/UVOT follow-up measurements
  15. GRB 050509b Milagro GeV/TeV Observations
  16. GRB050509B: Optical observations at the Very Large Telescope
  17. GRB 050509b: No Optical Variability in XRT Error Circle
  18. GRB 050509a: Swift-BAT refined analysis
  19. GRB 050509c: ROTSE-III Optical Limits
  20. GRB 050509B: WSRT Radio Observations
  21. GRB050509c: REM NIR and Optical observations (errata corrige to GCN 3400)
  22. GRB 050505, early TAROT observation
  23. GRB050509c (=H3751): An X-Ray Flash Localized By HETE
  24. GRB 050509b: Further Analysis of Keck LRIS Images
  25. GRB050509c: REM NIR and Optical observations
  26. GRB 050509b: Physical Properties of the Candidate Host galaxy
  27. GRB 050505: SARA Observations
  28. Swift UVOT Follow-up Observations of GRB 050509B
  29. GRB 050509B, Optical Observations
  30. GRB 050509B: Swift/XRT refined analysis
  31. GRB 050509b: Optical observations
  32. GRB 050509b: Precision Astrometry
  33. GRB 050509b: Possible Optical Counterpart
  34. Keck/DEIMOS Spectrum of Possible Host Galaxy for GRB050509b
  35. GRB 050509A: Optical observations
  36. GRB 050509b: Optical Counterpart Candidate
  37. GRB 050509b: PAIRITEL and WIYN Observations
  38. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  39. GRB 050509b: optical observations
  40. GRB 050509b: Swift XRT Position
  41. GRB 050509B: ROTSE-III Optical Limits
  42. GRB 050509a: Swift XRT Position
  43. Swift-BAT detection of GRB 050507
  44. GRB 050505: Keck I-band Magnitude
  45. GRB 050505: early time observations
  46. GRB 050505 - Faulkes Telescope North observations
  47. GRB 050502a: Swift XRT Upper Limit
  48. GRB 050505, simultaneous optical observation
  49. GRB 050505: Further Swift UVOT observations.
  50. GRB050505: AAVSO observations
  51. GRB050416A : 1 GHz limit from GMRT
  52. GRB 050505: Keck absorption spectrum and redshift (z=4.27)
  53. GRB 050505 UVOT
  54. GRB050505: Optical Afterglow Candidate
  55. GRB 050505: Swift XRT Position
  56. GRB 050502a: Optical Observations
  57. GRB 050416b:Swift XRT afterglow upper limits
  58. GRB 050416b:Swift XRT afterglow upper limits
  59. GRB 050504: Swift XRT position
  60. GRB050502: P200 Observations (Correction)
  61. GRB050502: P200 Observations
  62. GRB 050504 : R band observation at Lulin observatory
  63. Swift UVOT observation of GRB 050504
  64. GRB 050504, R band Observations
  65. GRB 050502b, V band Observations
  66. GRB050504: P60 Observations
  67. GRB 050504: A long GRB detected with INTEGRAL
  68. GRB (?) 050504: IR Observations, Intriguing Source
  69. GRB 050502b, Optical observations
  70. GRB050502a: P60 Observations (Correction)
  71. GRB050502a: P60 Observations
  72. Renewal of SGR 1806-20 activity
  73. GRB 050502a: RBO Observations
  74. GRB 050502A: WSRT Radio Observations
  75. GRB050502A: Optical Observations
  76. Swift UVOT refined analysis
  77. Retraction of Swift-BAT trigger 116145
  78. GRB 050502a : R band observation at Lulin observatory
  79. GRB 050502b : optical observation at Lulin observatory
  80. GRB 050502b: Swift XRT Position
  81. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  82. GRB 050502: INTEGRAL results
  83. GRB050502: ANU 1m optical Observations
  84. GRB 050502: Confirmed variability of the afterglow candidate +
  85. GRB 050502: PAIRITEL IR Observations
  86. GRB050502 - Correction on the Optical Candidate from the Liverpool
  87. GRB 050502 - A long GRB detected with INTEGRAL
  88. GRB 050502: ROTSE-III Detection of Possible Counterpart
  89. Swift-BAT Trigger 115881 is not a real GRB
  90. Swift/BAT possible detection of a weak burst GRB050430
  91. GRB 050401: Rc observation
  92. GRB050416a: Radio Detection
  93. GRB 050422: Swift-UVOT observation
  94. GRB 050422: Swift-BAT refined analysis
  95. GRB 050422: Swift XRT Position
  96. Swift Detection of GRB 050422
  97. GRB 050421: NIR observations
  98. GRB 050416: Optical/NIR observations
  99. GRB 050421: SLOTIS observations
  100. GRB 050421: Further Analysis of IR imaging

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