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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"

19549 results found.

  1. GRB071101: Optical and NIR upper limits by KANATA
  2. GRB0711101: Two new source from Xinglong TNT observation
  3. GRB 071101: TAROT Calern observatory optical observations
  4. GRB071101 LOAO B,V,R,I observation
  5. GRB 071101: Swift detection of a burst
  6. GRB 071031: Swift-XRT Team refined analysis
  7. GRB 071020: MITSuME Akeno optical observations
  8. GRB 071031: REM NIR and Optical observation
  9. GRB 071031: Swift detection of a burst with an optical counterpart
  10. GRB 071028B Swift-BAT detection of a burst
  11. GRB071025: Optical+NIR observations
  12. GRB 071028: SARA observations of variable source
  13. Swift UVOT upper limits to GRB071028
  14. GRB071028: Xinglong EST V-band upper limit
  15. GRB 071028: Swift-XRT Team refined analysis
  16. GRB 071028: Swift detection of a burst
  17. GRB 071003: Infrared Photometry with Keck Adaptive Optics
  18. GRB071021: MARGE Optical Limits
  19. GRB071020, optical upper limit
  20. GRB 071025: SARA VRI upper limits
  21. Swift UVOT upper limits
  22. GRB071025: Xinglong TNT I-band upper limit
  23. GRB 071025: Swift-XRT Team refined analysis
  24. GRB071021 : CFHT Ks-band observation
  25. GRB 071025: Swift XRT refined position
  26. GRB 071025a: PAIRITEL observations
  27. GRB 071025: Swift detection of a burst
  28. GRB 071021: R-band detection and analysis
  29. Possible radio detection of GRB 071021 with the VLA
  30. GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
  31. GRB 071020: SARA observations
  32. Radio detection of GRB 071020 with the VLA
  33. GRB071021: MITSuME Okayama Optical Upper Limits
  34. GRB 071021: Z-band detection
  35. GRB071018: 2nd epoch obsevations of Xinglong TNT
  36. GRB 071021: Xinglong TNT optical Upper Limit
  37. GRB 071021 : Lulin R-band limit
  38. GRB 071021: Swift detection of a burst
  39. GRB071020A: Xinglong TNT Optical afterglow observations
  40. GRB 071020, Swift-BAT refined analysis
  41. GRB 071020A: IR Imaging with PAIRITEL
  42. GRB071020 - SDSS Pre-burst Observations
  43. GRB 071020: Swift detection of a bright burst
  44. GRB 071018: Mercator Telescope optical observations
  45. GRB 071018: SARA observations
  46. GRB 071018: Swift-XRT observation
  47. GRB 071017 - Swift XRT observations
  48. GRB 071018: Possible OT from Xinglong TNT observation
  49. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  50. GRB 071018, Swift-BAT refined analysis
  51. GRB 071010B: Suzaku WAM observation of the prompt emission
  52. GRB 071013: 3rd TLS Epoch - constraints on variability
  53. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  54. GRB 071011: MITSuME Optical Observations
  55. GRB 070920A: deep optical observations at the NOT
  56. GRB 071010B: Keck/LRIS Photometry
  57. GRB 071013: TLS Upper Limit
  58. VLA non-detection of GRB 071011
  59. GRB 071013: Optical observations
  60. GRB 071013: optical observations at NOT
  61. GRB071010B, BVRcIc field calibration
  62. GRB 20071013: Xinglong TNT optical Upper Limit
  63. GRB 071010C Swift-BAT detection of a burst
  64. GRB 071011: Optical Limit after 13.95hrs
  65. GRB 071010B correction to GCN 6892 optical observations
  66. GRB 071011: Swift-XRT refined analysis
  67. VLA non-detection of GRB 071010A
  68. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  69. GRB 071011: Confirmation of P60 optical afterglow
  70. GRB 071010B: Optical Detection
  71. GRB 071011: Kanazawa Optical limits
  72. GRB 071011: P60 Optical Afterglow Candidate
  73. GRB 071011: MARGE Optical Limits
  74. GRB 071010B: Super-LOTIS upper limit
  75. GRB 071010B optical photometry
  76. GRB 071011: XRT afterglow detection
  77. GRB 071011: NAYUTA Optical Observation
  78. GRB 071010A: Continued Keck Imaging
  79. GRB 071010B: Bright OT confirmed with TLS
  80. Optical Observation: GRB 071010
  81. Optical observations: GRB 071010A
  82. GRB071010B: Swift/XRT detection
  83. GRB 071010B, Swift-BAT refined analysis
  84. GRB 071010A: Keck/LRIS Photometry
  85. GRB 071010 REM NIR observations
  86. GRB 071010: TAROT La Silla observatory detection of the afterglow
  87. GRB070920A: MAGIC telescope GeV observation
  88. Radio detection of GRB 071003 with the VLA
  89. GRB 071003: Possible rebrightening
  90. GRB 071003 : Lulin R-band observations
  91. GRB 071003: P60 Confirmation of Optical Afterglow
  92. Faulkes Telescope South observations of GRB 071001
  93. GRB 071001: Swift detection of a burst
  94. VLA observation of GRB 070923
  95. GRB 070911, SMARTS optical/IR afterglow observations
  96. GRB 070925: Gemini South Imaging
  97. GRB070925: Swift-XRT Position
  98. GRB 070920B: ROTSE-III Early Optical Limits
  99. GRB 070923, Swift-BAT refined analysis
  100. GRB 070920B: TAROT La Silla observatory optical observations

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