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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"
  1. GRB 071018: SARA observations
  2. GRB 071018: Swift-XRT observation
  3. GRB 071017 - Swift XRT observations
  4. VLA radio observation of GRB 071018
  5. GRB071018: Correction to the GCN 6936
  6. GRB071018: Correction to the GCN 6936
  7. GRB071018: Correction to the GCN 6936
  8. GRB071018: Correction to the title of the GCN 6936
  9. GRB 071018: Possible OT from Xinglong TNT observation
  10. GRB 071010B: Light Curve Break Confirmed
  11. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  12. GRB 071018, Swift-BAT refined analysis
  13. GRB 071018?: Swift detection of a possible burst
  14. GRB 071010B: Suzaku WAM observation of the prompt emission
  15. GRB 071013: 3rd TLS Epoch - constraints on variability
  16. GRB 071013: TNT optical data refined analysis
  17. GRB 071010B: Keck/DEIMOS emission-line redshift
  18. GRB 071017: a SHORT GRB detected by INTEGRAL
  19. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  20. GRB071013: optical observations
  21. GRB 071010B: Optical observations of EST
  22. GRB 071010B: TLS 3rd Epoch - finally a break??
  23. GRB 071011: MITSuME Optical Observations
  24. GRB 070920A: deep optical observations at the NOT
  25. GRB 071010B: Photometry after 1.6 days
  26. GRB 071010B: Keck/LRIS Photometry
  27. GRB 071010B: TLS 2nd Epoch, refined analysis
  28. GRB 071013: TLS Upper Limit
  29. Correction to GCN circular no. # 6915 for GRB 071010B
  30. VLA detection of radio afterglow of GRB 071010B
  31. VLA non-detection of GRB 071011
  32. GRB 071013: Optical observations
  33. GRB 071013: optical observations at NOT
  34. GRB 071013, Swift-BAT refined analysis
  35. GRB071013: optical limit
  36. GRB071010B, BVRcIc field calibration
  37. GRB 20071013: Xinglong TNT optical Upper Limit
  38. GRB 071013: Swift detection of a burst
  39. GRB 071010C Swift-BAT detection of a burst
  40. GRB 071011: Optical Limit after 13.95hrs
  41. GRB 071011: Xinglong TNT Optical afterglow observations
  42. GRB 071010B correction to GCN 6892 optical observations
  43. GRB 071011: Swift-XRT refined analysis
  44. VLA non-detection of GRB 071010A
  45. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  46. GRB 071011, Optical afterglow
  47. GRB 071011: Confirmation of P60 optical afterglow
  48. GRB 071010B: Optical Detection
  49. GRB 071011: Kanazawa Optical limits
  50. GRB 071011: P60 Optical Afterglow Candidate
  51. GRB 071011: MARGE Optical Limits
  52. GRB 071010B: Super-LOTIS upper limit
  53. GRB 071010B optical photometry
  54. GRB 071011: XRT afterglow detection
  55. GRB 071010B: Keck/LRIS Spectroscopy
  56. GRB 071011, Swift-BAT refined analysis
  57. GRB 071010B: Gemini Spectroscopic Observations
  58. GRB 071011: Early Super-LOTIS Observations
  59. GRB 071011: NAYUTA Optical Observation
  60. GRB 071010A: Continued Keck Imaging
  61. GRB 071010B: Bright OT confirmed with TLS
  62. GRB 071011: Optical afterglow candidate
  63. GRB 071011: Swift detection of a burst
  64. Optical Observation: GRB 071010
  65. Optical observations: GRB 071010A
  66. Konus-Wind observation of GRB 071010B
  67. GRB071010B: Swift/XRT detection
  68. GRB 071010B, Swift-BAT refined analysis
  69. GRB 071010A: bright NIR afterglow
  70. GRB 071006, Swift-BAT refined analysis
  71. GRB071008: optical observations
  72. GRB 071010B possible optical transient
  73. GRB 071010A: Keck/LRIS Photometry
  74. GRB 071010B: Swift detection of a burst
  75. GRB 071010: Swift-XRT observation
  76. GRB 071008, Swift-BAT refined analysis
  77. GRB 071010, Swift-BAT refined analysis
  78. Konus-Wind observation of GRB 071006
  79. GRB071008: Swift-XRT observation
  80. GRB 071010 REM NIR observations
  81. GRB 071010: Keck/LRIS Spectroscopy
  82. GRB 071010: TAROT La Silla observatory photometry of the afterglow
  83. GRB 071010: Rapid PROMPT Detections
  84. GRB 071010: Keck Observations of the Afterglow
  85. GRB 071010: TAROT La Silla observatory detection of the afterglow
  86. GRB 071010: Swift detection of a burst
  87. GRB 071006 Swift-BAT detection of a burst
  88. GRB071008: IAC80 observation
  89. GRB 071008: Swift detection of a burst
  90. GRB 071003: XRT refined analysis
  91. GRB070920A: MAGIC telescope GeV observation
  92. Radio detection of GRB 071003 with the VLA
  93. GRB 070810B: further XRT analysis
  94. GRB 071003: VLT spectroscopy
  95. GRB 071003: Keck spectroscopy
  96. Konus-Wind observation of GRB 071003
  97. GRB071003: Faulkes Telescope North observations
  98. GRB 071003: Possible rebrightening
  99. GRB 071003 : Lulin R-band observations
  100. GRB 071003: Swift XRT position

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