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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"

25055 results found.

  1. GRB071021: MARGE Optical Limits
  2. GRB071020, optical upper limit
  3. GRB 071025: SARA VRI upper limits
  4. Swift UVOT upper limits
  5. GRB071025: Xinglong TNT I-band upper limit
  6. GRB 071025: Swift-XRT Team refined analysis
  7. GRB 060602A: host redshift
  8. GRB 071025, Swift-BAT refined analysis
  9. GRB071021 : CFHT Ks-band observation
  10. GRB 071025: ROTSE-III Refined Analysis
  11. GRB 071025a: PAIRITEL observations
  12. GRB 071025: ROTSE-III Detection of Optical Counterpart
  13. GRB 071025: Swift detection of a burst
  14. GRB 071021: R-band detection and analysis
  15. Possible radio detection of GRB 071021 with the VLA
  16. GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
  17. GRB 071020: SARA observations
  18. Radio detection of GRB 071020 with the VLA
  19. GRB071021: MITSuME Okayama Optical Upper Limits
  20. GRB 071021: Z-band detection
  21. GRB 071021: optical and NIR observations
  22. GRB 071021: possible high-z burst
  23. GRB 071021, Swift-BAT refined analysis
  24. GRB071018: 2nd epoch obsevations of Xinglong TNT
  25. GRB 071021: Swift-XRT Team refined analysis
  26. GRB 071021: Xinglong TNT optical Upper Limit
  27. GRB 071021 : Lulin R-band limit
  28. GRB 071021: Swift detection of a burst
  29. GRB071020A: Xinglong TNT Optical afterglow observations
  30. GRB 071020: Swift-XRT refined analysis
  31. GRB 071020, Swift-BAT refined analysis
  32. GRB 071020A: IR Imaging with PAIRITEL
  33. GRB 071020: ROTSE-III Analysis of Optical Counterpart
  34. GRB071020 - SDSS Pre-burst Observations
  35. GRB 071020: Swift detection of a bright burst
  36. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  37. GRB 071018: Mercator Telescope optical observations
  38. Swift autonomous slewing re-enabled
  39. GRB 071018: SARA observations
  40. GRB 071018: Swift-XRT observation
  41. GRB 071017 - Swift XRT observations
  42. GRB 071018: Possible OT from Xinglong TNT observation
  43. GRB 071010B: Light Curve Break Confirmed
  44. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  45. GRB 071018, Swift-BAT refined analysis
  46. GRB 071010B: Suzaku WAM observation of the prompt emission
  47. GRB 071013: 3rd TLS Epoch - constraints on variability
  48. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  49. GRB 071010B: Optical observations of EST
  50. GRB 071011: MITSuME Optical Observations
  51. GRB 070920A: deep optical observations at the NOT
  52. GRB 071010B: Keck/LRIS Photometry
  53. GRB 071013: TLS Upper Limit
  54. VLA non-detection of GRB 071011
  55. GRB 071013: Optical observations
  56. GRB 071013: optical observations at NOT
  57. GRB 071013, Swift-BAT refined analysis
  58. GRB071010B, BVRcIc field calibration
  59. GRB 20071013: Xinglong TNT optical Upper Limit
  60. GRB 071010C Swift-BAT detection of a burst
  61. GRB 071011: Optical Limit after 13.95hrs
  62. GRB 071010B correction to GCN 6892 optical observations
  63. GRB 071011: Swift-XRT refined analysis
  64. VLA non-detection of GRB 071010A
  65. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  66. GRB 071011: Confirmation of P60 optical afterglow
  67. GRB 071010B: Optical Detection
  68. GRB 071011: Kanazawa Optical limits
  69. GRB 071011: P60 Optical Afterglow Candidate
  70. GRB 071011: MARGE Optical Limits
  71. GRB 071010B: Super-LOTIS upper limit
  72. GRB 071010B optical photometry
  73. GRB 071011: XRT afterglow detection
  74. GRB 071011, Swift-BAT refined analysis
  75. GRB 071010B: Gemini Spectroscopic Observations
  76. GRB 071011: NAYUTA Optical Observation
  77. GRB 071010A: Continued Keck Imaging
  78. GRB 071010B: Bright OT confirmed with TLS
  79. GRB 071011: Swift detection of a burst
  80. Optical Observation: GRB 071010
  81. Optical observations: GRB 071010A
  82. Konus-Wind observation of GRB 071010B
  83. GRB071010B: Swift/XRT detection
  84. GRB 071010B, Swift-BAT refined analysis
  85. GRB 071010A: bright NIR afterglow
  86. GRB 071006, Swift-BAT refined analysis
  87. GRB 071010A: Keck/LRIS Photometry
  88. GRB 071008, Swift-BAT refined analysis
  89. GRB 071010, Swift-BAT refined analysis
  90. GRB 071010 REM NIR observations
  91. GRB 071010: TAROT La Silla observatory detection of the afterglow
  92. GRB 071008: Swift detection of a burst
  93. GRB 071003: XRT refined analysis
  94. GRB070920A: MAGIC telescope GeV observation
  95. Radio detection of GRB 071003 with the VLA
  96. GRB 070810B: further XRT analysis
  97. GRB 071003: Possible rebrightening
  98. GRB 071003 : Lulin R-band observations
  99. GRB 071003: Keck HIRES spectroscopy
  100. GRB 071003, Swift-BAT refined analysis

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