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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"

28037 results found.

  1. Konus-Wind observation of GRB 050525
  2. GRB 050525: TAROT observations of the early afterglow
  3. INTEGRAL detection of GRB 050525
  4. GRB 050525, infrared observations
  5. GRB 050525: observatons of the optical afterglow
  6. GRB050525: ROTSE-III Refined Analysis
  7. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  8. XRF050522: Radio Observations
  9. Swift/UVOT observation of XRF 050522
  10. GRB 050509A: Further I-band imaging
  11. GRB050522,optical observation
  12. GRB050520,optical observation
  13. XRF 050522: Continued NIR P200 Monitoring
  14. RBO Observations of GRB050522
  15. Recent GRB BVRcIc field photometry
  16. GRB050520: Radio Observations
  17. XRF 050522: Swift XRT observation
  18. XRF050522, BVRcIc field photometry
  19. XRF050522: Optical Observations
  20. XRF050522: Near-infrared Observations
  21. GRB 050520: VLT/ULTRACAM observations
  22. GRB 050520: Swift XRT refined analysis
  23. XRF050509C: Chandra Afterglow Detection
  24. XRF050509c: Radio Observations
  25. GRB 050520: P200 Observations
  26. GRB 050520: TAROT optical limit
  27. GRB 050520: VLT/ULTRACAM observations
  28. XRF 050509c optical afterglow
  29. GRB 050509B and short GRB-SN association? (corrected)
  30. GRB 050509B and short GRB-SN association?
  31. GRB050502b: Early Observation
  32. GRB050509b, Bok telescope B-band imaging
  33. Refined Chandra analysis of GRB 050509b
  34. GRB050509b, SDSS pre-burst observations
  35. GRB 050509b: Keck/Chandra Cross-Correlation
  36. GRB 050509b: Keck/Chandra Cross-Correlation
  37. Chandra observation of GRB 050509b
  38. GRB 050509b: RAPTOR deep, early limits.
  39. GRB050509B: Optical observations at the Very Large Telescope
  40. GRB 050509b: No Optical Variability in XRT Error Circle
  41. GRB 050509a: Swift-BAT refined analysis
  42. GRB 050509c: ROTSE-III Optical Limits
  43. GRB 050505, early TAROT observation
  44. GRB050509c: REM NIR and Optical observations
  45. GRB 050509b: Physical Properties of the Candidate Host galaxy
  46. GRB 050505: SARA Observations
  47. GRB 050509B, Optical Observations
  48. GRB 050509B: Swift/XRT refined analysis
  49. GRB 050509b: Optical observations
  50. GRB 050509A: Optical observations
  51. GRB050509b: Radio Observations
  52. GRB 050509b: PAIRITEL and WIYN Observations
  53. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  54. Swift Detection of GRB050509b: A short duration burst
  55. Swift Detection of the Burst GRB050509
  56. GRB 050505: early time observations
  57. GRB 050505, simultaneous optical observation
  58. GRB050505: AAVSO observations
  59. GRB050416A : 1 GHz limit from GMRT
  60. GRB050505: Optical Afterglow Candidate
  61. GRB050505 Swift-BAT refined analysis
  62. GRB 050416b:Swift XRT afterglow upper limits
  63. GRB 050416b:Swift XRT afterglow upper limits
  64. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  65. GRB050502b: Afterglow Confirmation
  66. GRB050502: P200 Observations (Correction)
  67. GRB050502: P200 Observations
  68. GRB 050504 : R band observation at Lulin observatory
  69. Swift UVOT observation of GRB 050504
  70. GRB 050504, R band Observations
  71. GRB 050502b, V band Observations
  72. GRB050504: P60 Observations
  73. GRB 050504: A long GRB detected with INTEGRAL
  74. GRB (?) 050504: IR Observations, Intriguing Source
  75. GRB 050502b, Optical observations
  76. GRB050502a: P60 Observations (Correction)
  77. GRB050502a: P60 Observations
  78. Renewal of SGR 1806-20 activity
  79. GRB050502B Swift-BAT refined analysis
  80. Swift UVOT refined analysis
  81. GRB 050502a : R band observation at Lulin observatory
  82. GRB 050502b : optical observation at Lulin observatory
  83. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  84. Swift Detection of the Bright Burst GRB050502b
  85. GRB 050502: INTEGRAL results
  86. GRB 050502: ROTSE-III Detection of Possible Counterpart
  87. Swift/BAT possible detection of a weak burst GRB050430
  88. GRB050416a: Radio Detection
  89. GRB 050422: Swift-UVOT observation
  90. GRB 050422: Swift-BAT refined analysis
  91. Swift Detection of GRB 050422
  92. GRB 050421: SLOTIS observations
  93. GRB 050421: Further Analysis of IR imaging
  94. GRB050421: Radio Observations
  95. GRB050421: Radio Observations
  96. GRB 050421: IR Observations
  97. GRB 050421: Swift-BAT refined analysis
  98. GRB050421
  99. GRB 050421: early Swift XRT analysis results
  100. GRB 050421: NIR observations

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