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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"

26336 results found.

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

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