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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"

26324 results found.

  1. RBO Observations of GRB050522
  2. Recent GRB BVRcIc field photometry
  3. GRB050520: Radio Observations
  4. XRF 050522: Swift XRT observation
  5. XRF050522, BVRcIc field photometry
  6. XRF050522: Optical Observations
  7. XRF050522: Near-infrared Observations
  8. GRB 050520: VLT/ULTRACAM observations
  9. GRB 050520: Swift XRT refined analysis
  10. XRF050509C: Chandra Afterglow Detection
  11. XRF050509c: Radio Observations
  12. GRB 050520: P200 Observations
  13. GRB 050520: TAROT optical limit
  14. GRB 050520: VLT/ULTRACAM observations
  15. XRF 050509c optical afterglow
  16. GRB 050509B and short GRB-SN association? (corrected)
  17. GRB 050509B and short GRB-SN association?
  18. GRB050502b: Early Observation
  19. GRB050509b, Bok telescope B-band imaging
  20. Refined Chandra analysis of GRB 050509b
  21. GRB050509b, SDSS pre-burst observations
  22. GRB 050509b: Keck/Chandra Cross-Correlation
  23. GRB 050509b: Keck/Chandra Cross-Correlation
  24. Chandra observation of GRB 050509b
  25. GRB 050509b: RAPTOR deep, early limits.
  26. GRB050509B: Optical observations at the Very Large Telescope
  27. GRB 050509b: No Optical Variability in XRT Error Circle
  28. GRB 050509a: Swift-BAT refined analysis
  29. GRB 050509c: ROTSE-III Optical Limits
  30. GRB 050505, early TAROT observation
  31. GRB050509c: REM NIR and Optical observations
  32. GRB 050509b: Physical Properties of the Candidate Host galaxy
  33. GRB 050505: SARA Observations
  34. GRB 050509B, Optical Observations
  35. GRB 050509B: Swift/XRT refined analysis
  36. GRB 050509b: Optical observations
  37. GRB 050509A: Optical observations
  38. GRB050509b: Radio Observations
  39. GRB 050509b: PAIRITEL and WIYN Observations
  40. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  41. Swift Detection of GRB050509b: A short duration burst
  42. Swift Detection of the Burst GRB050509
  43. GRB 050505: early time observations
  44. GRB 050505, simultaneous optical observation
  45. GRB050505: AAVSO observations
  46. GRB050416A : 1 GHz limit from GMRT
  47. GRB050505: Optical Afterglow Candidate
  48. GRB050505 Swift-BAT refined analysis
  49. GRB 050416b:Swift XRT afterglow upper limits
  50. GRB 050416b:Swift XRT afterglow upper limits
  51. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  52. GRB050502b: Afterglow Confirmation
  53. GRB050502: P200 Observations (Correction)
  54. GRB050502: P200 Observations
  55. GRB 050504 : R band observation at Lulin observatory
  56. Swift UVOT observation of GRB 050504
  57. GRB 050504, R band Observations
  58. GRB 050502b, V band Observations
  59. GRB050504: P60 Observations
  60. GRB 050504: A long GRB detected with INTEGRAL
  61. GRB (?) 050504: IR Observations, Intriguing Source
  62. GRB 050502b, Optical observations
  63. GRB050502a: P60 Observations (Correction)
  64. GRB050502a: P60 Observations
  65. Renewal of SGR 1806-20 activity
  66. GRB050502B Swift-BAT refined analysis
  67. Swift UVOT refined analysis
  68. GRB 050502a : R band observation at Lulin observatory
  69. GRB 050502b : optical observation at Lulin observatory
  70. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  71. Swift Detection of the Bright Burst GRB050502b
  72. GRB 050502: INTEGRAL results
  73. GRB 050502: ROTSE-III Detection of Possible Counterpart
  74. Swift/BAT possible detection of a weak burst GRB050430
  75. GRB050416a: Radio Detection
  76. GRB 050422: Swift-UVOT observation
  77. GRB 050422: Swift-BAT refined analysis
  78. Swift Detection of GRB 050422
  79. GRB 050421: SLOTIS observations
  80. GRB 050421: Further Analysis of IR imaging
  81. GRB050421: Radio Observations
  82. GRB050421: Radio Observations
  83. GRB 050421: IR Observations
  84. GRB 050421: Swift-BAT refined analysis
  85. GRB050421
  86. GRB 050421: early Swift XRT analysis results
  87. GRB 050421: NIR observations
  88. GRB050421: P60 Observations
  89. GRB 050421: BOOTES-2 simultaneous optical observations
  90. GRB 050416b: Tentative Swift XRT Position
  91. GRB 050315: potential host galaxy
  92. GRB050326: analysis of the XMM-Newton observation
  93. GRB050418: Null Optical Observations
  94. GRB050416A, optical observations
  95. GRB 050418: Swift-BAT refined analysis
  96. GRB 050416: Mitsume optical observation
  97. GRB050416B: IR observations
  98. GRB050412: Radio Observations
  99. GRB 050416: Swift/UVOT detection of afterglow emission
  100. GRB050416: Refined Swift-XRT analysis

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