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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"

24895 results found.

  1. INTEGRAL detection of GRB 050525
  2. GRB 050525, infrared observations
  3. GRB 050525: observatons of the optical afterglow
  4. GRB050525: ROTSE-III Refined Analysis
  5. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  6. XRF050522: Radio Observations
  7. Swift/UVOT observation of XRF 050522
  8. GRB 050509A: Further I-band imaging
  9. GRB050522,optical observation
  10. GRB050520,optical observation
  11. XRF 050522: Continued NIR P200 Monitoring
  12. RBO Observations of GRB050522
  13. Recent GRB BVRcIc field photometry
  14. GRB050520: Radio Observations
  15. XRF 050522: Swift XRT observation
  16. XRF050522, BVRcIc field photometry
  17. XRF050522: Optical Observations
  18. XRF050522: Near-infrared Observations
  19. GRB 050520: VLT/ULTRACAM observations
  20. GRB 050520: Swift XRT refined analysis
  21. XRF050509C: Chandra Afterglow Detection
  22. XRF 050509c: Swift XRT Upper Limit
  23. XRF050509c: Radio Observations
  24. GRB 050520: P200 Observations
  25. GRB050520: Liverpool Telescope follow-up
  26. GRB 050520: TAROT optical limit
  27. GRB 050520: VLT/ULTRACAM observations
  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 Milagro GeV/TeV Observations
  38. GRB050509B: Optical observations at the Very Large Telescope
  39. GRB 050509b: No Optical Variability in XRT Error Circle
  40. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  41. GRB 050509c: ROTSE-III Optical Limits
  42. GRB 050505, early TAROT observation
  43. GRB050509c (=H3751): An X-Ray Flash Localized By HETE
  44. GRB050509c: REM NIR and Optical observations
  45. GRB 050505: SARA Observations
  46. GRB 050509B: Swift/XRT refined analysis
  47. GRB 050509A: Optical observations
  48. GRB050509b: Radio Observations
  49. Swift Detection of GRB050509b: A short duration burst
  50. Swift Detection of the Burst GRB050509
  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. Swift UVOT observation of GRB 050504
  63. GRB050504: P60 Observations
  64. GRB (?) 050504: IR Observations, Intriguing Source
  65. GRB 050502b, Optical observations
  66. GRB050502a: P60 Observations (Correction)
  67. GRB050502a: P60 Observations
  68. Renewal of SGR 1806-20 activity
  69. GRB 050502A: WSRT Radio Observations
  70. GRB050502B Swift-BAT refined analysis
  71. GRB050502B: I band source in XRT error circle
  72. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  73. GRB 050502: INTEGRAL results
  74. GRB 050502 - A long GRB detected with INTEGRAL
  75. GRB 050502: ROTSE-III Detection of Possible Counterpart
  76. Swift/BAT possible detection of a weak burst GRB050430
  77. GRB 050401: Rc observation
  78. GRB050416a: Radio Detection
  79. Swift Detection of GRB 050422
  80. GRB 050421: SLOTIS observations
  81. GRB 050421: Further Analysis of IR imaging
  82. GRB050421: Radio Observations
  83. GRB050421: Radio Observations
  84. GRB 050421: IR Observations
  85. GRB 050421: Swift-BAT refined analysis
  86. GRB050421
  87. GRB 050421: early Swift XRT analysis results
  88. GRB 050421: NIR observations
  89. GRB050421: P60 Observations
  90. GRB 050421: BOOTES-2 simultaneous optical observations
  91. GRB 050416b: Tentative Swift XRT Position
  92. GRB 050315: potential host galaxy
  93. GRB050326: analysis of the XMM-Newton observation
  94. GRB050418: Null Optical Observations
  95. GRB 050412: Chandra observations
  96. GRB050416A, optical observations
  97. GRB 050416: Mitsume optical observation
  98. GRB050416B: IR observations
  99. GRB050412: Radio Observations
  100. GRB 050416: Swift/UVOT detection of afterglow emission

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