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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"

20360 results found.

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

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