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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"

4572 results found.

  1. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  2. GRB051109A: XRT refined analysis
  3. GRB 051105b: ART optical limits
  4. GRB051028: Swift/UVOT upper limits
  5. GRB051021a: optical observations
  6. GRB051021b: Magellan IR Imaging
  7. GRB 051021: P200 Ks Observations
  8. GRB051021B: Swift XRT Position
  9. GRB 051016B: Swift detection of a soft burst
  10. GRB050805A: Rc optical observations
  11. GRB 051001: Swift XRT refined analysis
  12. GRB 050922C: further VLT observations
  13. GRB 050925: WSRT Radio Observations
  14. GRB050922B: refined XRT analysis
  15. GRB050922C: Optical Observations
  16. GRB050918: Possible Swift/XRT detected afterglow
  17. GRB 050916: Swift-BAT refined analysis
  18. GRB 050915b, SMARTS optical/IR observations of the XRT position
  19. GRB 050915B: Swift-BAT refined analysis
  20. GRB 050915B: XRT position
  21. GRB050915B: Swift-BAT detection of a long bright burst
  22. GRB 050915: Swift XRT refined analysis
  23. GRB 050915: ROTSE-III optical limits
  24. GRB 050915: Swift detection of a GRB
  25. GRB050908 : Swift-XRT refined analysis
  26. GRB 050908: KAIT observations
  27. GRB 050906: Swift/BAT Detection of a possible burst
  28. GRB 050824: MDM Observations
  29. GRB 050826: Swift XRT preliminary analysis results
  30. GRB050824: First 2 hours of power low optical decay?
  31. GRB 050824: ROTSE-III Optical Limits
  32. GRB050820A: RTT150 optical observations
  33. GRB 050822: Swift-BAT refined analysis
  34. GRB050820: refined XRT analysis
  35. GRB050819: refined XRT analysis
  36. GRB050819: Swift XRT position
  37. GRB 050803: early Swift XRT analysis results
  38. GRB 050802: early Swift XRT analysis results
  39. GRB 050730: XRT refined analysis
  40. GRB 050724: Chandra Observations of the X-ray Afterglow
  41. GRB050724: Refined Radio Position
  42. GRB050724: VLT observations of the variable source
  43. GRB 050726: early Swift XRT analysis results
  44. GRB 050724: J-band observations
  45. GRB050724: Radio Observation
  46. GRB 050724: spectroscopy of object in the XRT error circle
  47. GRB 050724: Optical limit
  48. GRB 050724: optical and near-IR observations
  49. GRB 050724: Optical imaging/astrometry
  50. GRB 050724: RTT150 optical observations
  51. GRB 050724: early Swift XRT analysis results
  52. GRB 050724: possible host galaxy in DSS
  53. GRB 050714, optical observations
  54. GRB 050713b : Lulin R-band observations
  55. GRB 050701: Refined XRT analysis
  56. GRB 050701: Swift XRT afterglow position
  57. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  58. XRF 050509c: Optical monitoring
  59. GRB 050525a, Mid-Infrared Observations
  60. GRB 050607: Optical decay and spectral slope
  61. GRB050607,optical observation
  62. GRB050525: Optical observations
  63. XRF050522: NIR observations of XRT candidate
  64. XRF 050522: Swift XRT refined analysis
  65. GRB050522,optical observation
  66. RBO Observations of GRB050522
  67. XRF 050522: Swift XRT observation
  68. RBO Observations of GRB050520
  69. GRB 050509a: Swift-BAT refined analysis
  70. Swift Detection of GRB050509b: A short duration burst
  71. GRB 050504: Swift XRT position
  72. GRB (?) 050504: IR Observations, Intriguing Source
  73. GRB 050502a: RBO Observations
  74. GRB050502B Swift-BAT refined analysis
  75. GRB 050416: Swift XRT Position
  76. GRB 050412: Swift-BAT refined analysis
  77. GRB 050401: Optical limit
  78. GRB 050408: Optical limit
  79. GRB 050408: Swift XRT measurement of possible jet break
  80. GRB050319: radio observation
  81. Konus-Wind observation of GRB 050326
  82. GRB 050319: Optical observation
  83. GRB050223: analysis of the XMM-Newton observation
  84. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  85. GRB050309: CONCAM pre-trigger and trigger coincident optical
  86. GRB 050219b: CORRECTION: Swift XRT Position
  87. GRB 050219b: Swift XRT Position
  88. GRB050209: REM optical observations
  89. GRB050124: No Swift UVOT Detection of Afterglow Emission
  90. GRB050124,optical observation
  91. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  92. GRB050123: P60 Observations
  93. Fourth Epoch VLA observations of SGR 1806-20
  94. GRB041219; RXTE ASM Observations
  95. GRB041223: decay of the afterglow
  96. GRB041223: optical and NIR observations with REM
  97. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  98. GRB 041219: Radio Afterglow Detection
  99. GRB 041218 : Radio Observations
  100. GRB 041217: LCO40 Optical Observations and Possible Candidates

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