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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"

5157 results found.

  1. GRB050918: Possible Swift/XRT detected afterglow
  2. GRB 050916: Swift-BAT refined analysis
  3. GRB 050915b, SMARTS optical/IR observations of the XRT position
  4. GRB 050915B: Swift-BAT refined analysis
  5. GRB 050915B: XRT position
  6. GRB050915B: Swift-BAT detection of a long bright burst
  7. GRB 050915: Swift XRT refined analysis
  8. GRB 050915: ROTSE-III optical limits
  9. GRB 050915: Swift detection of a GRB
  10. GRB050908 : Swift-XRT refined analysis
  11. GRB 050908: KAIT observations
  12. GRB 050906: Swift/BAT Detection of a possible burst
  13. GRB 050824: MDM Observations
  14. GRB 050826: Swift XRT preliminary analysis results
  15. GRB050824: First 2 hours of power low optical decay?
  16. GRB 050824: ROTSE-III Optical Limits
  17. GRB050820A: RTT150 optical observations
  18. GRB 050822: Swift-BAT refined analysis
  19. GRB050820: refined XRT analysis
  20. GRB050819: refined XRT analysis
  21. GRB050819: Swift XRT position
  22. GRB 050803: early Swift XRT analysis results
  23. GRB 050802: early Swift XRT analysis results
  24. GRB 050730: XRT refined analysis
  25. GRB 050724: Chandra Observations of the X-ray Afterglow
  26. GRB050724: Refined Radio Position
  27. GRB050724: VLT observations of the variable source
  28. GRB 050726: early Swift XRT analysis results
  29. GRB 050724: J-band observations
  30. GRB050724: Radio Observation
  31. GRB 050724: spectroscopy of object in the XRT error circle
  32. GRB 050724: Optical limit
  33. GRB 050724: optical and near-IR observations
  34. GRB 050724: Optical imaging/astrometry
  35. GRB 050724: RTT150 optical observations
  36. GRB 050724: early Swift XRT analysis results
  37. GRB 050724: possible host galaxy in DSS
  38. GRB 050714, optical observations
  39. GRB 050713b : Lulin R-band observations
  40. GRB 050701: Refined XRT analysis
  41. GRB 050701: Swift XRT afterglow position
  42. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  43. XRF 050509c: Optical monitoring
  44. GRB 050525a, Mid-Infrared Observations
  45. GRB 050607: Optical decay and spectral slope
  46. GRB050607,optical observation
  47. GRB050525: Optical observations
  48. XRF050522: NIR observations of XRT candidate
  49. XRF 050522: Swift XRT refined analysis
  50. GRB050522,optical observation
  51. RBO Observations of GRB050522
  52. XRF 050522: Swift XRT observation
  53. RBO Observations of GRB050520
  54. GRB 050509a: Swift-BAT refined analysis
  55. Swift Detection of GRB050509b: A short duration burst
  56. GRB 050504: Swift XRT position
  57. GRB (?) 050504: IR Observations, Intriguing Source
  58. GRB 050502a: RBO Observations
  59. GRB050502B Swift-BAT refined analysis
  60. GRB 050416: Swift XRT Position
  61. GRB 050412: Swift-BAT refined analysis
  62. GRB 050401: Optical limit
  63. GRB 050408: Optical limit
  64. GRB 050408: Swift XRT measurement of possible jet break
  65. GRB050319: radio observation
  66. Konus-Wind observation of GRB 050326
  67. GRB 050319: Optical observation
  68. GRB050223: analysis of the XMM-Newton observation
  69. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  70. GRB050309: CONCAM pre-trigger and trigger coincident optical
  71. GRB 050219b: CORRECTION: Swift XRT Position
  72. GRB 050219b: Swift XRT Position
  73. GRB050209: REM optical observations
  74. GRB050124: No Swift UVOT Detection of Afterglow Emission
  75. GRB050124,optical observation
  76. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  77. GRB050123: P60 Observations
  78. Fourth Epoch VLA observations of SGR 1806-20
  79. GRB041219; RXTE ASM Observations
  80. GRB041223: decay of the afterglow
  81. GRB041223: optical and NIR observations with REM
  82. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  83. GRB 041219: Radio Afterglow Detection
  84. GRB 041218 : Radio Observations
  85. GRB 041217: LCO40 Optical Observations and Possible Candidates
  86. GRB 041211: KAIT observations
  87. GRB970815: Discovery of Optical Afterglow
  88. GRB 040924: Afterglow Color
  89. GRB 041016: Optical limits
  90. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  91. GRB040924,optical observation
  92. GRB040924,optical observation
  93. GRB040924, RTT150 optical observation
  94. GRB 040924: Subaru NIR observation
  95. GRB 040924, optical follow-up
  96. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  97. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  98. IBAS GRB Alerts 1978-1980
  99. GRB040903 - A XRF?
  100. GRB040825A: optical limit before GRB

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