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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"

14851 results found.

  1. GRB 071025: Swift detection of a burst
  2. GRB 071021: R-band detection and analysis
  3. GRB 071020: BTA spectroscopy
  4. GRB071021: Optical+NIR observations
  5. Possible radio detection of GRB 071021 with the VLA
  6. Optical observations of GRB 071020
  7. GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
  8. Radio detection of GRB 071020 with the VLA
  9. GRB 071021: Magellan i-band observation
  10. GRB 071021: Z-band detection
  11. GRB 071010B: Fading quickly
  12. GRB 071021: optical and NIR observations
  13. GRB 071021: possible high-z burst
  14. GRB 071021: Swift detection of a burst
  15. GRB 071020, Swift-BAT refined analysis
  16. GRB 071020: Swift detection of a bright burst
  17. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  18. GRB 071018: Mercator Telescope optical observations
  19. GRB 071018?: Swift detection of a possible burst
  20. GRB 071013: 3rd TLS Epoch - constraints on variability
  21. GRB 071010B: Keck/DEIMOS emission-line redshift
  22. VLA detection of radio afterglow of GRB 071010B
  23. VLA non-detection of GRB 071011
  24. GRB 071013: Swift detection of a burst
  25. GRB 071010C Swift-BAT detection of a burst
  26. VLA non-detection of GRB 071010A
  27. GRB 071010B: Optical Detection
  28. GRB 071011: XRT afterglow detection
  29. GRB 071010B: Bright OT confirmed with TLS
  30. GRB 071011: Swift detection of a burst
  31. GRB071010B: Swift/XRT detection
  32. GRB 071010B possible optical transient
  33. GRB 071010B: Swift detection of a burst
  34. GRB 071010: Keck Observations of the Afterglow
  35. GRB 071010: TAROT La Silla observatory detection of the afterglow
  36. GRB 071010: Swift detection of a burst
  37. GRB 071006 Swift-BAT detection of a burst
  38. GRB071008: IAC80 observation
  39. GRB 071008: Swift detection of a burst
  40. Radio detection of GRB 071003 with the VLA
  41. GRB 071003: VLT spectroscopy
  42. GRB 071003: Possible rebrightening
  43. GRB 071003: OA power-law decay indices from KAIT
  44. GRB 071003: Keck HIRES spectroscopy
  45. GRB 071003: Swift detection of a bright burst
  46. GRB 071001: Swift detection of a burst
  47. VLA observation of GRB 070923
  48. GRB 070923: Swift detection of a short hard burst
  49. GRB 070920B: Swift detection of a burst
  50. GRB 070920: Swift detection of a burst
  51. SGR1806-20: Swift-BAT detection of enhanced activity
  52. GRB 070917: P60 Observations
  53. GRB 070917: Swift detection of a bright burst
  54. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  55. GRB 070913: Swift detection of a burst
  56. GRB 070911: Swift detection of a burst
  57. GRB 070824 - Combined SuperAGILE/IPN Localization
  58. GRB 070810A: ROTSE-III Refined Analysis
  59. GRB 070810B: Swift detection of a short burst
  60. No radio detection in superAGILE burst 070724B
  61. GRB 070810: ROTSE-III Detection of Optical Counterpart
  62. GRB 070810: Swift detection of a burst
  63. GRB 070809: Swift detection of a short burst
  64. GRB 070808: Swift detection of a burst
  65. GRB 070805: Swift detection of a burst
  66. Swift detection of a outburst from SAX J1810.8-2609
  67. VLA non-detection of GRB 070721B
  68. GRB 070802: VLT redshift
  69. GRB 070802: V-band detection of the candidate afterglow
  70. GRB 070802: LCO I-band candidate
  71. GRB 070802: Swift detection of a burst
  72. Swift/UVOT detection of GRB070714B
  73. AGILE-ACS position for the SGR 1806-20 July 27 burst
  74. GRB 070729: Swift detection of a short hard burst
  75. GRB070721A: Swift/UVOT Detection of a Weak Afterglow
  76. GRB 070724: optical observations
  77. GRB 070724: P60 and Gemini Observations
  78. GRB 060814 - Keck host detection and redshift
  79. GRB 070724: Swift detection of a burst
  80. GRB 070326: Detection of first burst from BAT Slew Survey (BATSS)
  81. GRB 070721B: optical observations and proposed redshift
  82. GRB 070721B: Swift detection of a burst
  83. GRB 070721: Swift detection of a possible burst
  84. GRB 070707: Swift-XRT follow-up observations
  85. GRB 070714: Swift detection of a bright burst, possibly short
  86. Swift detection of a possible burst (Trigger 284850)
  87. GRB 070707: object inside XRT error circle
  88. GRB070704: FAVOR optical observations
  89. VLA detection of GRB 070612A in C Band
  90. GRB 070704: Swift detection of a burst
  91. GRB 070628 Swift-UVOT Refined Analysis
  92. GRB 070628: NIR detection of afterglow
  93. GRB 070628: Swift detection of a possible burst
  94. GRB 070612A: Allen Telescope Array Observations
  95. INTEGRAL burst GRB070615: X-ray continued observations
  96. GRB 070612A: Second Epoch WSRT Radio Observations
  97. Keck Laser Guide Star Adaptive Optics Imaging of GRB 070621
  98. GRB 070621: Swift detection of a burst
  99. Swift/UVOT detection of GRB070616 optical afterglow.
  100. GRB 070612A: Possible WSRT Radio Detection

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