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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"

28081 results found.

  1. GRB 071109: IBIS refined analysis
  2. GRB 071104: Swift-XRT Team Refined Analysis
  3. GRB 071104: Possible Swift UVOT Afterglow Candidate
  4. GRB 071104: Swift-XRT position
  5. GRB 071104: Gamma Ray Burst Localization by SuperAGILE
  6. Swift XRT and UVOT observations of GRB071028B
  7. GRB 071101, Swift-BAT refined analysis
  8. GRB 071101: Swift-XRT Team refined analysis
  9. GRB071101: Optical and NIR upper limits by KANATA
  10. GRB0711101: Two new source from Xinglong TNT observation
  11. GRB 071101: TAROT Calern observatory optical observations
  12. GRB071101 LOAO B,V,R,I observation
  13. GRB 071101: Swift detection of a burst
  14. GRB 071031, Swift-BAT refined analysis
  15. GRB 071031: Swift-XRT Team refined analysis
  16. GRB 071020: MITSuME Akeno optical observations
  17. GRB 071031: REM NIR and Optical observation
  18. GRB 071031: Swift detection of a burst with an optical counterpart
  19. GRB 071028B Swift-BAT detection of a burst
  20. GRB 071028: SARA observations of variable source
  21. Swift UVOT upper limits to GRB071028
  22. GRB071028: Xinglong EST V-band upper limit
  23. GRB 071028: Swift-XRT Team refined analysis
  24. GRB 071028, Swift-BAT refined analysis
  25. GRB 071028: Swift detection of a burst
  26. GRB 071003: Infrared Photometry with Keck Adaptive Optics
  27. GRB071021: MARGE Optical Limits
  28. GRB071020, optical upper limit
  29. GRB 071025: SARA VRI upper limits
  30. Swift UVOT upper limits
  31. GRB071025: Xinglong TNT I-band upper limit
  32. GRB 071025: Swift-XRT Team refined analysis
  33. GRB 060602A: host redshift
  34. GRB 071025, Swift-BAT refined analysis
  35. GRB071021 : CFHT Ks-band observation
  36. GRB 071025: ROTSE-III Refined Analysis
  37. GRB 071025a: PAIRITEL observations
  38. GRB 071025: ROTSE-III Detection of Optical Counterpart
  39. GRB 071025: Swift detection of a burst
  40. GRB 071021: R-band detection and analysis
  41. Possible radio detection of GRB 071021 with the VLA
  42. GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
  43. GRB 071020: SARA observations
  44. Radio detection of GRB 071020 with the VLA
  45. GRB071021: MITSuME Okayama Optical Upper Limits
  46. GRB 071021: Z-band detection
  47. GRB 071021: optical and NIR observations
  48. GRB 071021: possible high-z burst
  49. GRB 071021, Swift-BAT refined analysis
  50. GRB071018: 2nd epoch obsevations of Xinglong TNT
  51. GRB 071021: Swift-XRT Team refined analysis
  52. GRB 071021: Xinglong TNT optical Upper Limit
  53. GRB 071021 : Lulin R-band limit
  54. GRB 071021: Swift detection of a burst
  55. GRB071020A: Xinglong TNT Optical afterglow observations
  56. GRB 071020: Swift-XRT refined analysis
  57. GRB 071020, Swift-BAT refined analysis
  58. GRB 071020A: IR Imaging with PAIRITEL
  59. GRB 071020: ROTSE-III Analysis of Optical Counterpart
  60. GRB071020 - SDSS Pre-burst Observations
  61. GRB 071020: Swift detection of a bright burst
  62. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  63. GRB 071018: Mercator Telescope optical observations
  64. Swift autonomous slewing re-enabled
  65. GRB 071018: SARA observations
  66. GRB 071018: Swift-XRT observation
  67. GRB 071017 - Swift XRT observations
  68. GRB 071018: Possible OT from Xinglong TNT observation
  69. GRB 071010B: Light Curve Break Confirmed
  70. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  71. GRB 071018, Swift-BAT refined analysis
  72. GRB 071010B: Suzaku WAM observation of the prompt emission
  73. GRB 071013: 3rd TLS Epoch - constraints on variability
  74. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  75. GRB 071010B: Optical observations of EST
  76. GRB 071011: MITSuME Optical Observations
  77. GRB 070920A: deep optical observations at the NOT
  78. GRB 071010B: Keck/LRIS Photometry
  79. GRB 071013: TLS Upper Limit
  80. VLA non-detection of GRB 071011
  81. GRB 071013: Optical observations
  82. GRB 071013: optical observations at NOT
  83. GRB 071013, Swift-BAT refined analysis
  84. GRB071010B, BVRcIc field calibration
  85. GRB 20071013: Xinglong TNT optical Upper Limit
  86. GRB 071010C Swift-BAT detection of a burst
  87. GRB 071011: Optical Limit after 13.95hrs
  88. GRB 071010B correction to GCN 6892 optical observations
  89. GRB 071011: Swift-XRT refined analysis
  90. VLA non-detection of GRB 071010A
  91. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  92. GRB 071011: Confirmation of P60 optical afterglow
  93. GRB 071010B: Optical Detection
  94. GRB 071011: Kanazawa Optical limits
  95. GRB 071011: P60 Optical Afterglow Candidate
  96. GRB 071011: MARGE Optical Limits
  97. GRB 071010B: Super-LOTIS upper limit
  98. GRB 071010B optical photometry
  99. GRB 071011: XRT afterglow detection
  100. GRB 071011, Swift-BAT refined analysis

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