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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

43683 results found.

  1. GRB 041218: optical observations
  2. Very high activity of SGR 1806-20
  3. GRB 041219: Second Epoch WSRT Radio Observations
  4. GRB 041219: WSRT Radio Afterglow Detection
  5. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  6. GRB 041218: Optical observations
  7. GRB041220: Swift-BAT burst
  8. Deep RAPTOR observations during GRB 041219
  9. GRB 041218 Optical Observations
  10. GRB 041219 Optical Observations
  11. GRB041219c: Third Burst in One Day from Swift-BAT
  12. GRB041219: Optical Afterglow Detection
  13. GRB041219: Continued NIR Observations
  14. GRB041219b: A Swift-BAT burst
  15. GRB 041219 ,optical observation
  16. GRB 041219: Radio Afterglow Detection
  17. GRB 041218 : Radio Observations
  18. GRB 041218: R-band optical observations
  19. GRB041218: Liverpool Telescope optical observations
  20. GRB041219: Confirmed NIR Afterglow
  21. Swift-BAT detection of the bright long burst GRB041219
  22. GRB 041218: Optical Observation
  23. GRB 041219: Infrared Afterglow Candidate
  24. GRB041219, BVRcIc field calibration
  25. GRB 041219: Infrared Afterglow Candidate
  26. GRB041218, BVRcIc field calibration
  27. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  28. GRB041219: P60 Optical Observations
  29. GRB 041219 - A long GRB detected by INTEGRAL
  30. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  31. GRB 041217: PROMPT Observations
  32. GRB041218: optical observations
  33. GRB 041218; optical candidate
  34. GRB 041218: Optical observations
  35. GRB 041217: LCO40 Optical Observations and Possible Candidates
  36. GRB 041218 - A long GRB detected by integral
  37. GRB041217: Optical Observations
  38. GRB041217: NIR and optical observations with REM
  39. GRB041217: P60 Optical Observations
  40. GRB041217: Infrared Observations
  41. GRB041217: The First GRB Located On-Board Swift
  42. GRB041211: Faulkes Telescope continued optical monitoring
  43. Optical Transient in Lynx not a GRB
  44. Optical transient (GRB?) in Lynx
  45. Optical transient (GRB?) in Lynx, UT Dec 11.4436
  46. GRB041211: RAPTOR observations
  47. GRB041211: Ashra Prototype optical observation
  48. GRB041211, Faulkes Telescope optical observation
  49. GRB041211, BVRcIc field calibration
  50. GRB 041211: Infrared Observations
  51. GRB 041211: KAIT observations
  52. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  53. GRB041211: P60 optical imaging
  54. GRB970815: Discovery of Optical Afterglow
  55. Distribution of IBAS Alerts for NON-GRB sources
  56. Triangulation of short GRB 041116 (large error box)
  57. GRB 040924: Afterglow Color
  58. GRB 041006: GETS Optical Afterglow Observation
  59. Summary of the recent bursts from SGR 1806-20
  60. GRB 041006: Optical Observations
  61. GRB041006, late-time optical photometry
  62. GRB041015, optical observation in CrAO
  63. IBAS GRB Alert # 2034
  64. GRB041006: RTT150 Optical Observations
  65. GRB041015 : Multi epoch optical observations
  66. HST Observations: XRF 040701 and 040812
  67. Bright bursts from SGR1806-20
  68. GRB 041016: BOOTES-2 simultaneous observation
  69. GRB041006: RTT150 Optical Observations
  70. GRB041016,optical observation
  71. GRB 041016: Optical limits
  72. GRB 041016: Optical limits in V, R, I
  73. GRB 041016:Optical limit during first minute
  74. GRB 041015: Optical Observations at Rikubetsu
  75. GRB 041016: Optical limit
  76. GRB040924, BVRcIc field calibration
  77. GRB041006: Fading X-ray Afterglow Observed with Chandra
  78. GRB041015 : Optical follow-up at Kiso
  79. GRB 041015 - A long GRB detected by INTEGRAL
  80. GRB 041006 R observations in Loiano
  81. GRB041006: VLT observations of the afterglow and host galaxy
  82. GRB041006: Optical observations and Potential host galaxy
  83. GRB041006, BVRcIc field calibration
  84. GRB 040924: VLT spectroscopy
  85. GRB 041006: SARA afterglow observations
  86. GRB041006, optical observation in CrAO
  87. Search for SN light in XRF 040912 with MEGACAM
  88. GRB 040916: Afterglow Color at Early Times
  89. GRB 041006 Optical afterglow observations
  90. IBAS GRB Alert # 2010
  91. GRB 041006: BR observations with VATT
  92. GRB 041006: Redshift confirmed
  93. GRB041006: Liverpool Telescope optical observations
  94. GRB 041006: Colour measurement
  95. GRB041006: break in the light curve
  96. GRB 041006: Radio Observations
  97. GRB 041006 : optical follow-up observation at Lulin Observatory
  98. GRB 041006 : Optical follow-up observation at TAROT
  99. GRB041006: Optical photometry and spectroscopy at TNG
  100. GRB 041006: presice astrometry

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