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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"

26170 results found.

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

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