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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"

8296 results found.

  1. GRB 131108A Tiled Swift observations
  2. GRB 131105A: TAROT La Silla observatory optical observations
  3. GRB 131105A: VLT/X-shooter optical afterglow candidate
  4. GRB 131105A: Swift detection of a burst
  5. GRB 131103A: Swift detection of a burst
  6. GRB 131031A: Swift/UVOT Upper Limits
  7. GRB 131031A: 1.23m CAHA afterglow candidate
  8. GRB 131030A: Swift detection of a burst with an optical counterpart
  9. GRB 131029A Tiled Swift observations
  10. Swift 575905/GRB 131026A: optical observations
  11. Swift Trigger 575905: a possible GRB
  12. GRB 131024B: Swift detection of a burst
  13. GRB 131024A: Swift detection of a burst
  14. GRB 131014A: RATIR Optical/NIR Afterglow Retraction
  15. GRB 131018B: Swift/UVOT Upper Limits
  16. GRB 131018B: Fermi-LAT detection of a burst
  17. GRB 131018A: Swift detection of a burst
  18. GRB 131014A: GROND observations
  19. GRB 131014A: Swift/UVOT Upper Limits
  20. GRB 131014A: RATIR Optical and NIR Observations
  21. GRB 131014A: NOT afterglow candidate
  22. GRB 131014A Tiled Swift observations
  23. GRB 131011A: Fermi GBM detection
  24. iPTF 13dsw/Fermi403206457: X-Shooter redshift
  25. Swift-XRT detection of iPTF 13dsw/Fermi403206457
  26. GRB 131011A: GROND afterglow observations
  27. Fermi403206457: continued P60 observations and fading behavior
  28. Fermi403206457: Weihai optical upper limit
  29. Fermi403206457: NOT optical observations
  30. Fermi403206457: iPTF detection of a possible optical afterglow
  31. Trigger 574266 is not a Swift detection of a known source
  32. GRB 130925A: Possible signatures of binary nature in the afterglow - Request for observations
  33. GRB 131004A: TNG optical afterglow confirmation
  34. GRB 131004A: Swift detection of a burst (may be short)
  35. GRB 130925A/Sw J0244-2609: mm observations at PdBI
  36. NuSTAR observations of GRB 130925A
  37. GRB 131002B: Swift detection of a burst
  38. GRB 131002A: Swift detection of a burst
  39. GRB 130929A: Swift detection of a burst
  40. Observation of possible GRB/TDE 130925A by INTEGRAL/SPI-ACS: three activity episodes
  41. GRB 130925A: Initial Similarities to Swift J1644+57
  42. GRB 130925A: GROND afterglow candidate
  43. GRB 130925A: Swift detection of a burst
  44. IPN Triangulation of SGR-like burst 130913 - probable association with SGR/AXP 1E1841-045
  45. INTEGRAL detection of a SGR-like burst likely from SGR J1745-29
  46. Fermi/GBM Detection of two SGR-like bursts possibly associated with SGR J1833-0832
  47. GRB 130912A: Swift detection of a short burst
  48. GRB 130907A: WSRT radio detection
  49. GRB 130907A: Swift detection of a burst with an optical counterpart
  50. Swift follow-up of an INTEGRAL possible weak GRB
  51. GRB 130903A: ISON-Kislovodsk optical Upper Limits
  52. Swift Trigger 569022: a possible GRB
  53. GRB 130831B: Swift detection of a burst
  54. GRB 130831A: Swift detection of a burst with an optical counterpart
  55. GRB 130828A Tiled Swift observations
  56. GRB 130822A: Swift detection of a short burst
  57. GRB 130816B: GROND afterglow candidate
  58. GRB 130816B: Swift detection of a burst
  59. GRB 130816A: REM NIR candidate afterglow
  60. GRB 130816A: Swift detection of a burst
  61. GRB 130812A: Swift detection of a burst
  62. GRB 130807A: Swift-XRT refined analysis
  63. GRB 130807A, Swift-BAT refined analysis
  64. GRB 130807A: Swift detection of a GRB or Galactic transient
  65. GRB 130806A: Swift detection of a burst
  66. Trigger 565443: Swift detection of a burst from SGR J1745-29
  67. GRB 130803A: Faulkes Telescope South Observations
  68. GRB 130803A: Swift detection of a burst
  69. GRB 130722A: RATIR Optical Observations
  70. GRB 130727A: Swift-XRT and Swift-UVOT prompt observations
  71. GRB 130725A: MITSuME Ishigakijima Optical Observation
  72. GRB 130719A: Skynet/PROMPT observations
  73. Swift Trigger 563980 is GRB 130725A
  74. GRB 130702A in the Ep,i - Eiso plane
  75. GRB 130722C Tiled Swift observations
  76. GRB 130722A: Faulkes Telescope South optical candidate
  77. GRB 130722A: Swift detection of a burst
  78. GRB 130702A: WSRT radio detection
  79. Konus-Wind observation of GRB 130702A
  80. GRB130702A: Redshift of Afterglow Candidate iPTF13bxl
  81. GRB 130702A / Fermi394416326: Fermi GBM detection
  82. GRB 130701A: Swift detection of a burst
  83. GRB 130626A: KAIT Optical Observations
  84. GRB 130626A: RATIR Optical Observations
  85. GRB130627B: Swift/UVOT Observations
  86. GRB 130626A: Swift-XRT possible detection and UVOT upper limits
  87. GRB 130627A: Swift/UVOT Observation
  88. GRB 130626A: Swift detection of a short burst
  89. GRB 130625A: Swift detection of a burst
  90. GRB 130614A: Suzaku WAM observation of the prompt emission
  91. Swift Trigger 558631 is not a real source
  92. GRB 130612A: Swift-BAT refined analysis
  93. GRB 130610A: CrAO optical observations
  94. GRB 130615A: Zadko observatory - Gingin optical observations
  95. GRB 130615A: TAROT La Silla observatory optical observations
  96. GRB 130615A: GROND afterglow candidate
  97. GRB 130615A: Swift detection of a burst
  98. GRB 130612A: Liverpool Telescope Afterglow detection
  99. GRB 130612A: Swift detection of a burst with an optical counterpart
  100. GRB 130606B: Swift/UVOT Upper Limit

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