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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"

20359 results found.

  1. Swift-BAT Time History of GRB041219
  2. GRB 041219: TAROT optical observations
  3. GRB 041218: TAROT optical observations
  4. GRB 041223: J-band observations of the afterglow
  5. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  6. GRB 041219c: PROMPT Observations
  7. GRB041223: Swift-BAT detection of a bright long burst
  8. GRB 041218 Optical Observations
  9. GRB041219: Continued NIR Observations
  10. GRB 041219 ,optical observation
  11. GRB 041219: Radio Afterglow Detection
  12. GRB 041218 : Radio Observations
  13. GRB 041218: R-band optical observations
  14. GRB041218: optical observations
  15. GRB041219: Confirmed NIR Afterglow
  16. GRB041218: Continued P60 Optical Observations
  17. Swift-BAT detection of the bright long burst GRB041219
  18. GRB 041219: Infrared Afterglow Candidate
  19. GRB041219, BVRcIc field calibration
  20. GRB 041219: Infrared Afterglow Candidate
  21. GRB041218, BVRcIc field calibration
  22. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  23. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  24. GRB 041217: PROMPT Observations
  25. GRB 041218: Optical observations
  26. GRB 041217: LCO40 Optical Observations and Possible Candidates
  27. GRB041217: NIR and optical observations with REM
  28. GRB041217: Infrared Observations
  29. GRB041217: The First GRB Located On-Board Swift
  30. GRB041211: Faulkes Telescope continued optical monitoring
  31. Optical transient (GRB?) in Lynx
  32. GRB041211: RAPTOR observations
  33. GRB041211: Ashra Prototype optical observation
  34. GRB041211, BVRcIc field calibration
  35. GRB041211,optical observation
  36. GRB 041211: Infrared Observations
  37. GRB 041211: KAIT observations
  38. Triangulation of short GRB 041116 (large error box)
  39. GRB 040924: Afterglow Color
  40. GRB 041006: GETS Optical Afterglow Observation
  41. GRB 041006: Optical Observations
  42. GRB041006, late-time optical photometry
  43. GRB041006: RTT150 Optical Observations
  44. GRB 041016: BOOTES-2 simultaneous observation
  45. GRB041006: RTT150 Optical Observations
  46. GRB041016,optical observation
  47. GRB 041016: Optical limits
  48. GRB 041016:Optical limit during first minute
  49. GRB 041016: Optical limit
  50. GRB 041015 R band observations
  51. GRB040924, BVRcIc field calibration
  52. GRB041015,optical observation
  53. GRB041006: Fading X-ray Afterglow Observed with Chandra
  54. GRB041006: Optical observations and Potential host galaxy
  55. GRB041006, BVRcIc field calibration
  56. GRB 041006: SARA afterglow observations
  57. GRB041006, optical observation in CrAO
  58. Search for SN light in XRF 040912 with MEGACAM
  59. GRB 041006: BR observations with VATT
  60. GRB 041006: Redshift confirmed
  61. GRB041006, optical I observation
  62. ROTSE-IIIa Observations of GRB 041006
  63. GRB041006: MASTER optical observations
  64. GRB041006,optical observation
  65. GRB041006: Fading of optical afterglow candidate
  66. GRB 041006: Optical afterglow candidate
  67. radio observations, GRB 040924
  68. GRB040929,optical observation
  69. GRB040924,optical observation
  70. GRB040924,optical observation
  71. GRB040924: KAIT observations
  72. GRB 040924: Subaru NIR observation
  73. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  74. XRF040916: continuing decay of OT
  75. TAROT Observations of GRB 040916 (HETE #3558)
  76. GRB040912(=H3557): Candidate Optical Afterglow
  77. XRF040916, optical observations
  78. XRF 040912, identification of CXO sources
  79. XRF040912, BVRcIc field calibration
  80. XRF040916, BVRcIc field calibration
  81. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  82. GRB040916: Optical observations
  83. GRB 040912: Optical Observations
  84. GRB/XRF040912,optical observations
  85. GRB 040912, BVRI observations
  86. GRB040912 : Kiso Optical follow-up observation
  87. Optical observations of field of GRB040912
  88. HETE 3557: Optical observations
  89. GRB040903 - A XRF?
  90. GRB040827: analysis of the XMM-Newton observation
  91. GRB040903, REM near-IR observation
  92. Very bright burst detected from SGR 1806-20
  93. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  94. GRB 040827 - Radio Observations
  95. XMM-Newton Images of GRB 040827
  96. GRB 040827: optical and NIR observations at the VLT
  97. GRB 040827: Possible detection of optical afterglow
  98. GRB040827 XMM-Newton observation
  99. GRB040825A: optical limit before GRB
  100. GRB 040825B: Optical observations

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