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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"

31635 results found.

  1. Swift XRT and UVOT observations of GRB071028B
  2. GRB 071101, Swift-BAT refined analysis
  3. GRB 071101: Swift-XRT Team refined analysis
  4. GRB071101: Optical and NIR upper limits by KANATA
  5. GRB0711101: Two new source from Xinglong TNT observation
  6. GRB 071101: TAROT Calern observatory optical observations
  7. GRB 071101: Swift XRT position
  8. GRB 071101: BOOTES-2 prompt optical observations
  9. GRB 071101: a nearby galaxy
  10. GRB 071031, Swift-BAT refined analysis
  11. GRB 071031: Swift/UVOT detection of afterglow
  12. GRB 071031: Swift-XRT Team refined analysis
  13. GRB 071020: MITSuME Akeno optical observations
  14. GRB 071031: REM NIR and Optical observation
  15. GRB 071031, SMARTS afterglow observations
  16. GRB 071031: VLT high-resolution spectroscopy
  17. GRB071031: Rapid PROMPT Detections
  18. GRB 071028B Swift-BAT detection of a burst
  19. GRB071025: Optical+NIR observations
  20. GRB 071028: SARA observations of variable source
  21. Swift UVOT upper limits to GRB071028
  22. GRB 071028: Swift-XRT Team refined analysis
  23. GRB 071028, Swift-BAT refined analysis
  24. GRB 071025: Kuiper Telescope Optical Observations
  25. GRB 071003: Infrared Photometry with Keck Adaptive Optics
  26. GRB 071018: Revised BAT position
  27. GRB 071025A: RAPTOR Observations of Complex Early Optical Behavior
  28. GRB071021: MARGE Optical Limits
  29. GRB071020, optical upper limit
  30. GRB 071025: SARA VRI upper limits
  31. GRB 071025 Milagro GeV/TeV Observations
  32. GRB071025: Optical Pre-imaging from Palomar
  33. Swift UVOT upper limits
  34. GRB071025: Xinglong TNT I-band upper limit
  35. GRB 071025: Swift-XRT Team refined analysis
  36. GRB 071025, Swift-BAT refined analysis
  37. GRB 071025: Early Super-LOTIS Observations
  38. GRB 071025: R/I-band update
  39. GRB071021 : CFHT Ks-band observation
  40. GRB 071025: ROTSE-III Refined Analysis
  41. GRB 071025: Swift XRT refined position
  42. GRB 071025a: PAIRITEL observations
  43. GRB071025: REM NIR afterglow
  44. GRB 071025: ROTSE-III Detection of Optical Counterpart
  45. GRB 071021: R-band detection and analysis
  46. GRB 071020: BTA spectroscopy
  47. GRB071021: Optical+NIR observations
  48. Possible radio detection of GRB 071021 with the VLA
  49. Optical observations of GRB 071020
  50. GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
  51. GRB 071020: SARA observations
  52. Radio detection of GRB 071020 with the VLA
  53. GRB071010b: optical observation
  54. GRB 071021: Subaru NIR observation
  55. GRB 071021: Magellan i-band observation
  56. GRB 071021: Z-band detection
  57. GRB 071020: Fading slowly?
  58. GRB 071010B: Fading quickly
  59. GRB 071021: optical and NIR observations
  60. GRB 071021: possible high-z burst
  61. GRB 071021, Swift-BAT refined analysis
  62. GRB071018: 2nd epoch obsevations of Xinglong TNT
  63. GRB 071021: retraction of Faulkes Telescope South candidate
  64. GRB 071021: Swift-XRT Team refined analysis
  65. GRB 071021: Xinglong TNT optical Upper Limit
  66. GRB 071021 : Lulin R-band limit
  67. Konus-Wind observation of GRB 071020
  68. GRB 071021: Faulkes Telescope South optical candidate
  69. GRB 071010B: Independent Confirmation of Break
  70. GRB071020A: Xinglong TNT Optical afterglow observations
  71. GRB 071020: Swift-XRT refined analysis
  72. GRB 071020, Swift-BAT refined analysis
  73. GRB 071020A: IR Imaging with PAIRITEL
  74. GRB 071020: VLT spectroscopy
  75. GRB 071020: ROTSE-III Analysis of Optical Counterpart
  76. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  77. Swift autonomous slewing re-enabled
  78. GRB071010b: optical observations
  79. GRB 071018: SARA observations
  80. GRB 071018: Swift-XRT observation
  81. GRB 071017 - Swift XRT observations
  82. VLA radio observation of GRB 071018
  83. GRB071018: Correction to the GCN 6936
  84. GRB071018: Correction to the GCN 6936
  85. GRB071018: Correction to the GCN 6936
  86. GRB071018: Correction to the title of the GCN 6936
  87. GRB 071018: Possible OT from Xinglong TNT observation
  88. GRB 071010B: Light Curve Break Confirmed
  89. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  90. GRB 071018, Swift-BAT refined analysis
  91. GRB 071010B: Suzaku WAM observation of the prompt emission
  92. GRB 071013: 3rd TLS Epoch - constraints on variability
  93. GRB 071013: TNT optical data refined analysis
  94. GRB 071010B: Keck/DEIMOS emission-line redshift
  95. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  96. GRB071013: optical observations
  97. GRB 071010B: Optical observations of EST
  98. GRB 071010B: TLS 3rd Epoch - finally a break??
  99. GRB 071011: MITSuME Optical Observations
  100. GRB 070920A: deep optical observations at the NOT

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