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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').
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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"

15247 results found.

  1. GRB 050713, R-band observations at NOT
  2. GRB050709, optical observations
  3. GRB050709: A Possible Short-Hard GRB Localized by HETE
  4. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  5. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  6. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  7. GRB 050416(a): Host Galaxy Redshift Determination
  8. GRB050607: refined analysis of prompt REM observations
  9. GRB 050607: RAPTOR-S Early Optical Limits
  10. GRB050607: KAIT optical limits
  11. GRB 050525a, Mid-Infrared Observations
  12. GRB 050607: Optical decay and spectral slope
  13. GRB050607,optical observation
  14. GRB 050607 - XRT refined data analysis
  15. GRB 050603: prediction of t_break
  16. GRB 050603: Redshift
  17. Konus-Wind observation of GRB 050603
  18. GRB 050603: Analysis of UVOT data
  19. GRB050603: Fading Afterglow observed by Swift UVOT
  20. GRB050603, submillimetre observations
  21. GRB 050603: Swift XRT Position
  22. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  23. GRB 050603: INTEGRAL shows it is not a short GRB
  24. GRB 050408: jet break in the XRT light curve
  25. GRB 050525a, SMARTS optical/IR afterglow observations
  26. GRB050528: BOOTES optical candidate (retraction)
  27. Possible GRB050528: no candidate from Liverpool Telescope
  28. GRB 050509b: refined XRT/Chandra afterglow position analysis
  29. GRB 050525B: Swift-BAT observations
  30. GRB050525A,optical observation
  31. GRB 050525 : Lulin optical afterglow observations
  32. GRB050525: Super-LOTIS observations
  33. GRB 050525, spectral lag pseudo-redshift
  34. GRB 050525: BART optical observation
  35. GRB 050525A: Swift-BAT refined analysis
  36. GRB050525: Optical observations
  37. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  38. Konus-Wind observation of GRB 050525
  39. GRB 050525: TAROT observations of the early afterglow
  40. GRB 050525, infrared observations
  41. GRB 050525: observatons of the optical afterglow
  42. GRB050525: ROTSE-III Refined Analysis
  43. XRF050522: NIR observations of XRT candidate
  44. XRF 050522: Swift XRT refined analysis
  45. XRF 050522: Swift XRT observation
  46. XRF050522, BVRcIc field photometry
  47. XRF050522: Optical Observations
  48. XRF 050522 detected with INTEGRAL
  49. GRB 050520: VLT/ULTRACAM observations
  50. GRB 050520: Swift XRT refined analysis
  51. GRB 050520: Swift XRT position
  52. GRB 050520: VLT/ULTRACAM observations
  53. GRB 050520 - A long GRB detected with INTEGRAL
  54. GRB 050504: Swift XRT afterglow candidate has faded
  55. GRB 050509B and short GRB-SN association? (corrected)
  56. GRB 050509B and short GRB-SN association?
  57. Refined Chandra analysis of GRB 050509b
  58. GRB050509b, SDSS pre-burst observations
  59. GRB 050509b: Keck/Chandra Cross-Correlation
  60. GRB 050509b: Keck/Chandra Cross-Correlation
  61. Chandra observation of GRB 050509b
  62. GRB 050509b Milagro GeV/TeV Observations
  63. GRB050509B: Optical observations at the Very Large Telescope
  64. GRB 050509c: ROTSE-III Optical Limits
  65. GRB 050505, early TAROT observation
  66. GRB 050509b: Further Analysis of Keck LRIS Images
  67. GRB 050509b: Precision Astrometry
  68. GRB 050509b: optical observations
  69. GRB 050509b: Swift XRT Position
  70. GRB 050509a: Swift XRT Position
  71. GRB 050505: Keck I-band Magnitude
  72. GRB050505: AAVSO observations
  73. GRB050416A : 1 GHz limit from GMRT
  74. GRB 050505: Keck absorption spectrum and redshift (z=4.27)
  75. GRB050505: Optical Afterglow Candidate
  76. GRB 050505: Swift XRT Position
  77. GRB 050504: Swift XRT position
  78. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  79. GRB050502b: Afterglow Confirmation
  80. GRB050502: P200 Observations (Correction)
  81. GRB050502: P200 Observations
  82. GRB 050504: A long GRB detected with INTEGRAL
  83. GRB050502a: P60 Observations (Correction)
  84. GRB050502a: P60 Observations
  85. GRB 050502a: RBO Observations
  86. GRB050502A: Optical Observations
  87. Swift UVOT refined analysis
  88. GRB 050502b: Swift XRT Position
  89. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  90. GRB050502B: Optical Limits from ANU 1m
  91. GRB 050502: INTEGRAL results
  92. GRB 050502: PAIRITEL IR Observations
  93. GRB050416a: Radio Detection
  94. GRB 050422: Swift XRT Position
  95. GRB 050421: SLOTIS observations
  96. GRB 050421: Further Analysis of IR imaging
  97. GRB 050421: early Swift XRT analysis results
  98. GRB050421: P60 Observations
  99. GRB 050421: Optical observations at the INT
  100. Swift Detection of GRB050421

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