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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"

26331 results found.

  1. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  2. XRF050522: Radio Observations
  3. Swift/UVOT observation of XRF 050522
  4. GRB 050509A: Further I-band imaging
  5. GRB050522,optical observation
  6. GRB050520,optical observation
  7. XRF 050522: Continued NIR P200 Monitoring
  8. RBO Observations of GRB050522
  9. Recent GRB BVRcIc field photometry
  10. GRB050520: Radio Observations
  11. XRF 050522: Swift XRT observation
  12. XRF050522, BVRcIc field photometry
  13. XRF050522: Optical Observations
  14. XRF050522: Near-infrared Observations
  15. GRB 050520: VLT/ULTRACAM observations
  16. GRB 050520: Swift XRT refined analysis
  17. XRF050509C: Chandra Afterglow Detection
  18. XRF050509c: Radio Observations
  19. GRB 050520: P200 Observations
  20. GRB 050520: TAROT optical limit
  21. GRB 050520: VLT/ULTRACAM observations
  22. XRF 050509c optical afterglow
  23. GRB 050509B and short GRB-SN association? (corrected)
  24. GRB 050509B and short GRB-SN association?
  25. GRB050502b: Early Observation
  26. GRB050509b, Bok telescope B-band imaging
  27. Refined Chandra analysis of GRB 050509b
  28. GRB050509b, SDSS pre-burst observations
  29. GRB 050509b: Keck/Chandra Cross-Correlation
  30. GRB 050509b: Keck/Chandra Cross-Correlation
  31. Chandra observation of GRB 050509b
  32. GRB 050509b: RAPTOR deep, early limits.
  33. GRB050509B: Optical observations at the Very Large Telescope
  34. GRB 050509b: No Optical Variability in XRT Error Circle
  35. GRB 050509a: Swift-BAT refined analysis
  36. GRB 050509c: ROTSE-III Optical Limits
  37. GRB 050505, early TAROT observation
  38. GRB050509c: REM NIR and Optical observations
  39. GRB 050509b: Physical Properties of the Candidate Host galaxy
  40. GRB 050505: SARA Observations
  41. GRB 050509B, Optical Observations
  42. GRB 050509B: Swift/XRT refined analysis
  43. GRB 050509b: Optical observations
  44. GRB 050509A: Optical observations
  45. GRB050509b: Radio Observations
  46. GRB 050509b: PAIRITEL and WIYN Observations
  47. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  48. Swift Detection of GRB050509b: A short duration burst
  49. Swift Detection of the Burst GRB050509
  50. GRB 050505: early time observations
  51. GRB 050505, simultaneous optical observation
  52. GRB050505: AAVSO observations
  53. GRB050416A : 1 GHz limit from GMRT
  54. GRB050505: Optical Afterglow Candidate
  55. GRB050505 Swift-BAT refined analysis
  56. GRB 050416b:Swift XRT afterglow upper limits
  57. GRB 050416b:Swift XRT afterglow upper limits
  58. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  59. GRB050502b: Afterglow Confirmation
  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. GRB050502B Swift-BAT refined analysis
  74. Swift UVOT refined analysis
  75. GRB 050502a : R band observation at Lulin observatory
  76. GRB 050502b : optical observation at Lulin observatory
  77. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  78. Swift Detection of the Bright Burst GRB050502b
  79. GRB 050502: INTEGRAL results
  80. GRB 050502: ROTSE-III Detection of Possible Counterpart
  81. Swift/BAT possible detection of a weak burst GRB050430
  82. GRB050416a: Radio Detection
  83. GRB 050422: Swift-UVOT observation
  84. GRB 050422: Swift-BAT refined analysis
  85. Swift Detection of GRB 050422
  86. GRB 050421: SLOTIS observations
  87. GRB 050421: Further Analysis of IR imaging
  88. GRB050421: Radio Observations
  89. GRB050421: Radio Observations
  90. GRB 050421: IR Observations
  91. GRB 050421: Swift-BAT refined analysis
  92. GRB050421
  93. GRB 050421: early Swift XRT analysis results
  94. GRB 050421: NIR observations
  95. GRB050421: P60 Observations
  96. GRB 050421: BOOTES-2 simultaneous optical observations
  97. GRB 050416b: Tentative Swift XRT Position
  98. GRB 050315: potential host galaxy
  99. GRB050326: analysis of the XMM-Newton observation
  100. GRB050418: Null Optical Observations

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