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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"

20361 results found.

  1. GRB 041224: near-infrared observations with REM
  2. GRB041223: optical and NIR observations with REM
  3. Swift-BAT Time History of GRB041219
  4. GRB 041219: TAROT optical observations
  5. GRB 041218: TAROT optical observations
  6. GRB 041223: J-band observations of the afterglow
  7. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  8. GRB 041219c: PROMPT Observations
  9. GRB041223: Swift-BAT detection of a bright long burst
  10. GRB 041218 Optical Observations
  11. GRB041219: Continued NIR Observations
  12. GRB 041219 ,optical observation
  13. GRB 041219: Radio Afterglow Detection
  14. GRB 041218 : Radio Observations
  15. GRB 041218: R-band optical observations
  16. GRB041218: optical observations
  17. GRB041219: Confirmed NIR Afterglow
  18. GRB041218: Continued P60 Optical Observations
  19. Swift-BAT detection of the bright long burst GRB041219
  20. GRB 041219: Infrared Afterglow Candidate
  21. GRB041219, BVRcIc field calibration
  22. GRB 041219: Infrared Afterglow Candidate
  23. GRB041218, BVRcIc field calibration
  24. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  25. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  26. GRB 041217: PROMPT Observations
  27. GRB 041218: Optical observations
  28. GRB 041217: LCO40 Optical Observations and Possible Candidates
  29. GRB041217: NIR and optical observations with REM
  30. GRB041217: Infrared Observations
  31. GRB041217: The First GRB Located On-Board Swift
  32. GRB041211: Faulkes Telescope continued optical monitoring
  33. Optical transient (GRB?) in Lynx
  34. GRB041211: RAPTOR observations
  35. GRB041211: Ashra Prototype optical observation
  36. GRB041211, BVRcIc field calibration
  37. GRB041211,optical observation
  38. GRB 041211: Infrared Observations
  39. GRB 041211: KAIT observations
  40. Triangulation of short GRB 041116 (large error box)
  41. GRB 040924: Afterglow Color
  42. GRB 041006: GETS Optical Afterglow Observation
  43. GRB 041006: Optical Observations
  44. GRB041006, late-time optical photometry
  45. GRB041006: RTT150 Optical Observations
  46. GRB 041016: BOOTES-2 simultaneous observation
  47. GRB041006: RTT150 Optical Observations
  48. GRB041016,optical observation
  49. GRB 041016: Optical limits
  50. GRB 041016:Optical limit during first minute
  51. GRB 041016: Optical limit
  52. GRB 041015 R band observations
  53. GRB040924, BVRcIc field calibration
  54. GRB041015,optical observation
  55. GRB041006: Fading X-ray Afterglow Observed with Chandra
  56. GRB041006: Optical observations and Potential host galaxy
  57. GRB041006, BVRcIc field calibration
  58. GRB 041006: SARA afterglow observations
  59. GRB041006, optical observation in CrAO
  60. Search for SN light in XRF 040912 with MEGACAM
  61. GRB 041006: BR observations with VATT
  62. GRB 041006: Redshift confirmed
  63. GRB041006, optical I observation
  64. ROTSE-IIIa Observations of GRB 041006
  65. GRB041006: MASTER optical observations
  66. GRB041006,optical observation
  67. GRB041006: Fading of optical afterglow candidate
  68. GRB 041006: Optical afterglow candidate
  69. radio observations, GRB 040924
  70. GRB040929,optical observation
  71. GRB040924,optical observation
  72. GRB040924,optical observation
  73. GRB040924: KAIT observations
  74. GRB 040924: Subaru NIR observation
  75. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  76. XRF040916: continuing decay of OT
  77. TAROT Observations of GRB 040916 (HETE #3558)
  78. GRB040912(=H3557): Candidate Optical Afterglow
  79. XRF040916, optical observations
  80. XRF 040912, identification of CXO sources
  81. XRF040912, BVRcIc field calibration
  82. XRF040916, BVRcIc field calibration
  83. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  84. GRB040916: Optical observations
  85. GRB 040912: Optical Observations
  86. GRB/XRF040912,optical observations
  87. GRB 040912, BVRI observations
  88. GRB040912 : Kiso Optical follow-up observation
  89. Optical observations of field of GRB040912
  90. HETE 3557: Optical observations
  91. GRB040903 - A XRF?
  92. GRB040827: analysis of the XMM-Newton observation
  93. GRB040903, REM near-IR observation
  94. Very bright burst detected from SGR 1806-20
  95. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  96. GRB 040827 - Radio Observations
  97. XMM-Newton Images of GRB 040827
  98. GRB 040827: optical and NIR observations at the VLT
  99. GRB 040827: Possible detection of optical afterglow
  100. GRB040827 XMM-Newton observation

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