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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"

18332 results found.

  1. GRB071025: Optical+NIR observations
  2. GRB 071028: SARA observations of variable source
  3. Swift UVOT upper limits to GRB071028
  4. GRB071028: Xinglong EST V-band upper limit
  5. GRB 071028: Swift-XRT Team refined analysis
  6. GRB 071028: Swift detection of a burst
  7. GRB 071003: Infrared Photometry with Keck Adaptive Optics
  8. GRB071021: MARGE Optical Limits
  9. GRB071020, optical upper limit
  10. GRB 071025: SARA VRI upper limits
  11. Swift UVOT upper limits
  12. GRB071025: Xinglong TNT I-band upper limit
  13. GRB 071025: Swift-XRT Team refined analysis
  14. GRB071021 : CFHT Ks-band observation
  15. GRB 071025: Swift XRT refined position
  16. GRB 071025a: PAIRITEL observations
  17. GRB 071025: Swift detection of a burst
  18. GRB 071021: R-band detection and analysis
  19. Possible radio detection of GRB 071021 with the VLA
  20. GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
  21. GRB 071020: SARA observations
  22. Radio detection of GRB 071020 with the VLA
  23. GRB071021: MITSuME Okayama Optical Upper Limits
  24. GRB 071021: Z-band detection
  25. GRB071018: 2nd epoch obsevations of Xinglong TNT
  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-BAT refined analysis
  31. GRB 071020A: IR Imaging with PAIRITEL
  32. GRB071020 - SDSS Pre-burst Observations
  33. GRB 071020: Swift detection of a bright burst
  34. GRB 071018: Mercator Telescope optical observations
  35. GRB 071018: SARA observations
  36. GRB 071018: Swift-XRT observation
  37. GRB 071017 - Swift XRT observations
  38. GRB 071018: Possible OT from Xinglong TNT observation
  39. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  40. GRB 071018, Swift-BAT refined analysis
  41. GRB 071013: 3rd TLS Epoch - constraints on variability
  42. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  43. GRB 071011: MITSuME Optical Observations
  44. GRB 070920A: deep optical observations at the NOT
  45. GRB 071010B: Keck/LRIS Photometry
  46. GRB 071013: TLS Upper Limit
  47. VLA non-detection of GRB 071011
  48. GRB 071013: Optical observations
  49. GRB 071013: optical observations at NOT
  50. GRB071010B, BVRcIc field calibration
  51. GRB 20071013: Xinglong TNT optical Upper Limit
  52. GRB 071010C Swift-BAT detection of a burst
  53. GRB 071011: Optical Limit after 13.95hrs
  54. GRB 071010B correction to GCN 6892 optical observations
  55. GRB 071011: Swift-XRT refined analysis
  56. VLA non-detection of GRB 071010A
  57. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  58. GRB 071011: Confirmation of P60 optical afterglow
  59. GRB 071010B: Optical Detection
  60. GRB 071011: Kanazawa Optical limits
  61. GRB 071011: P60 Optical Afterglow Candidate
  62. GRB 071011: MARGE Optical Limits
  63. GRB 071010B: Super-LOTIS upper limit
  64. GRB 071010B optical photometry
  65. GRB 071011: XRT afterglow detection
  66. GRB 071011: NAYUTA Optical Observation
  67. GRB 071010A: Continued Keck Imaging
  68. GRB 071010B: Bright OT confirmed with TLS
  69. Optical Observation: GRB 071010
  70. Optical observations: GRB 071010A
  71. GRB071010B: Swift/XRT detection
  72. GRB071008: optical observations
  73. GRB 071010A: Keck/LRIS Photometry
  74. GRB 071010 REM NIR observations
  75. GRB 071010: TAROT La Silla observatory detection of the afterglow
  76. Radio detection of GRB 071003 with the VLA
  77. GRB 071003: Possible rebrightening
  78. GRB 071003 : Lulin R-band observations
  79. GRB 071003: MARGE Observations
  80. GRB 071003: P60 Confirmation of Optical Afterglow
  81. GRB 071001: Swift-XRT Team refined analysis
  82. Faulkes Telescope South observations of GRB 071001
  83. GRB 071001: Swift detection of a burst
  84. VLA observation of GRB 070923
  85. GRB 070911, SMARTS optical/IR afterglow observations
  86. GRB 070925: Gemini South Imaging
  87. GRB 070920B: ROTSE-III Early Optical Limits
  88. GRB 070920B: TAROT La Silla observatory optical observations
  89. GRB 070920B: NOT optical observations
  90. GRB 070920: TAROT Calern observatory optical observations
  91. GRB 070917: P60 Observations
  92. GRB 070917: MITSuME Akeno Ic upper limit
  93. GRB 070917: R band observations
  94. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  95. GRB 070809: The Swift evidence for the SHB nature of this burst
  96. GRB 070913: SMARTS optical/IR observations
  97. GRB 070913: TAROT La Silla observatory optical observations
  98. GRB 070911: PAIRITEL IR Observations
  99. GRB 070911: Swift XRT refined analysis
  100. GRB 070809: Confirmation of optical transient

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