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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').
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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"

28057 results found.

  1. SGR1806-20: Swift-BAT observations of two additional bursts
  2. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  3. Further VLA observations of SGR 1806-20
  4. SGR 1806-20 and extragalactic short-duration GRBs
  5. Further ATCA observations of SGR 1806-20
  6. Fourth Epoch VLA observations of SGR 1806-20
  7. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  8. ATCA observations of SGR 1806-20
  9. SGR 1806-20, RHESSI observations of the 041227 giant flare
  10. Third epoch observations of SGR 1806-20 with VLA
  11. Second Epoch VLA observations of SGR 1806-20
  12. Second-epoch VLA observations of SGR 1806-20
  13. SGR1806 VLA Observations
  14. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  15. GRB 041217: Optical observations
  16. GRB041228: Swift-BAT detection of a burst
  17. GRB041219; RXTE ASM Observations
  18. NIR Observations of GRB 041219
  19. GRB041226: Swift-BAT detection of a burst
  20. GRB041223: decay of the afterglow
  21. GRB 041224: near-infrared observations with REM
  22. GRB 041223 Fluence measured by Swift-BAT
  23. GRB041223: optical and NIR observations with REM
  24. Swift-BAT Time History of GRB041219
  25. GRB 041219: TAROT optical observations
  26. GRB 041218: TAROT optical observations
  27. GRB 041223: J-band observations of the afterglow
  28. GRB 041219c: PROMPT Observations
  29. GRB041223: Swift-BAT detection of a bright long burst
  30. GRB 041218: optical observations
  31. GRB 041219 : optical follow-up observations
  32. Deep RAPTOR observations during GRB 041219
  33. GRB 041218 Optical Observations
  34. GRB041219: Continued NIR Observations
  35. GRB 041219 ,optical observation
  36. GRB 041219: Radio Afterglow Detection
  37. GRB 041218 : Radio Observations
  38. GRB 041218: R-band optical observations
  39. GRB041218: optical observations
  40. GRB041219: Confirmed NIR Afterglow
  41. Swift-BAT detection of the bright long burst GRB041219
  42. GRB 041219: Infrared Afterglow Candidate
  43. GRB041219, BVRcIc field calibration
  44. GRB 041219: Infrared Afterglow Candidate
  45. GRB041218, BVRcIc field calibration
  46. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  47. GRB 041219 - A long GRB detected by INTEGRAL
  48. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  49. GRB 041217: PROMPT Observations
  50. GRB 041217: LCO40 Optical Observations and Possible Candidates
  51. GRB 041218 - A long GRB detected by integral
  52. GRB041217: NIR and optical observations with REM
  53. GRB041217: Infrared Observations
  54. GRB041217: The First GRB Located On-Board Swift
  55. GRB041211: Faulkes Telescope continued optical monitoring
  56. Optical Transient in Lynx not a GRB
  57. Optical transient (GRB?) in Lynx
  58. GRB041211: RAPTOR observations
  59. GRB041211: Ashra Prototype optical observation
  60. GRB041211, BVRcIc field calibration
  61. GRB041211,optical observation
  62. GRB 041211: Infrared Observations
  63. GRB 041211: KAIT observations
  64. GRB 041211: Optical follow-up in East Asian region
  65. Triangulation of short GRB 041116 (large error box)
  66. GRB 040924: Afterglow Color
  67. GRB 041006: GETS Optical Afterglow Observation
  68. Summary of the recent bursts from SGR 1806-20
  69. GRB 041006: Optical Observations
  70. GRB041006, late-time optical photometry
  71. GRB041006: RTT150 Optical Observations
  72. HST Observations: XRF 040701 and 040812
  73. Bright bursts from SGR1806-20
  74. GRB 041016: BOOTES-2 simultaneous observation
  75. GRB041006: RTT150 Optical Observations
  76. GRB041016,optical observation
  77. GRB 041016: Optical limits
  78. GRB 041016:Optical limit during first minute
  79. GRB 041015: Optical Observations at Rikubetsu
  80. GRB 041016: Optical limit
  81. GRB 041015 R band observations
  82. GRB040924, BVRcIc field calibration
  83. GRB041015,optical observation
  84. GRB041006: Fading X-ray Afterglow Observed with Chandra
  85. GRB 041015 - A long GRB detected by INTEGRAL
  86. GRB041006: VLT observations of the afterglow and host galaxy
  87. GRB041006: Optical observations and Potential host galaxy
  88. GRB041006, BVRcIc field calibration
  89. GRB 040924: VLT spectroscopy
  90. GRB 041006: SARA afterglow observations
  91. GRB041006, optical observation in CrAO
  92. Search for SN light in XRF 040912 with MEGACAM
  93. GRB 041006: BR observations with VATT
  94. GRB 041006: Redshift confirmed
  95. GRB 041006: Radio Observations
  96. GRB 041006 : optical follow-up observation at Lulin Observatory
  97. GRB041006: Optical photometry and spectroscopy at TNG
  98. GRB 041006: presice astrometry
  99. GRB041006, optical I observation
  100. GRB041006 (=HETE3570): optical observations

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