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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 100414A: Gemini-N observation (correction)
  2. GRB 100414A: GROND Detection of the Optical Afterglow
  3. GRB 100414A: Gemini-N candidate and redshift
  4. GRB 100414A: Enhanced Swift-XRT position of candidate afterglow
  5. GRB 100413A: Suzaku WAM observation of the prompt emission
  6. GRB 100414A: Palomar Transient Factory Observations
  7. GRB 100413B: Swift Confirmation of Burst
  8. GRB 100414A: Swift-XRT detection of a possible X-ray afterglow
  9. GRB 100413A: Swift-BAT final refined analysis
  10. GRB 100414A: IPN Localization
  11. Konus-Wind observation of GRB 100414A (correction to GCN 10597)
  12. Konus-Wind observation of GRB 100414B
  13. GRB 100415A: MAXI/GSC detection of a probable GRB
  14. GRB 100414A: Fermi GBM detection
  15. GRB100414A: Fermi LAT detection
  16. GRB 100413B : Swift detection of a burst
  17. GRB 100413A: GROND Upper limits
  18. GRB 100413A: Swift/UVOT Upper Limits
  19. Konus-Wind observation of GRB 100413A
  20. GRB 100413A: Faulkes Telescope South observations
  21. Tentative redshift of GRB100413A from X-ray data
  22. GRB 100413A: SARA upper limit
  23. GRB 100413A: Swift-XRT Refined Analysis
  24. GRB 100413A: Swift-BAT initial refined analysis
  25. GRB 100413A: Enhanced Swift-XRT position
  26. GRB 100413: xinglong TNT optical upper limit
  27. GRB 100413A: MASTER-Net optical observations
  28. GRB 100413A: Swift detection of a burst
  29. Spin down rate and inferred dipole magnetic field of the new soft gamma-ray repeater SGR 1833-0832
  30. Swift-BAT trigger 419015 is not astrophysical
  31. Trigger 419015 is probably not a GRB
  32. GRB100401A: GROND Upper Limits
  33. INTEGRAL Alert n. 5995: MASTER-Net optical observations
  34. MASTER observations on the Swift second trigger on LS V +44 17
  35. IBAS Alert n. 5996: not a GRB
  36. IBAS Alert n. 5995: not a GRB
  37. GRB 100331B: GROND Upper limits
  38. Master-Net observations on the Swift trigger on LS V +44 17
  39. GRB 100401A: Swift/UVOT Upper Limit
  40. Swift/BAT trigger 417974 (GRB100401A): Swift/XRT observations
  41. GRB 100401A: Fermi GBM detection
  42. GRB 100401A Burst, possibly short, detected in ground analysis of BAT data
  43. GRB 100331B: BOOTES-3 observations
  44. GRB 100316A: R-band limit
  45. GRB 100324B: Suzaku WAM observation of the prompt emission
  46. GRB 100331B: Swift/UVOT Upper Limits
  47. GRB 100331B: Swift/XRT possible afterglow candidate
  48. Swift detection of LS V +44 17
  49. GRB 100331B: SuperAGILE Localization of a Long GRB
  50. INTEGRAL trigger 5994 (GRB100331A): Swift/XRT observations
  51. INTEGRAL trigger 5994 / GRB 100331A: GROND detection of a variable source
  52. GRB 100331A: BOOTES-3 observations
  53. Konus-Wind observation of GRB 100324B
  54. GRB 100331A: A long GRB detected by INTEGRAL
  55. IPN triangulation of GRB100324B
  56. Konus-Wind observation of GRB 100322A
  57. Short X-ray Transient detected by MAXI/GSC
  58. Fermi GBM detection of four Solar Flares
  59. GRB 100322A: Suzaku WAM observation of the prompt emission
  60. Fermi/GBM and Swift/BAT detection of a burst from SGR 1806-20
  61. GRB 100325A: Fermi LAT detection
  62. GROND observations of GRB100316D/SN2010bh
  63. GRB 100325A: Fermi GBM detection
  64. GRB 100324A: GROND observations
  65. GRB 100324A found in ground analysis of BAT data
  66. Emerging Supernova in the Afterglow of GRB 100316D
  67. GRB 100322B or possible Galactic transient detected in ground analysis of BAT data
  68. GRB 100316D: Spectroscopic Discovery of a Supernova from Magellan
  69. SGR 1833-0832: Swift/UVOT Upper Limits
  70. GRB 100322A: Fermi GBM detection
  71. SGR 1833-0832: Archival Chandra Observations
  72. SGR 1833-0832 is pulsed at 7.56 seconds
  73. SGR 1833-0832 is pulsed at 7.56 seconds
  74. Possible pulsation period in SGR 1833-0832
  75. Discovery of the Spin Period of SGR 1833-0832
  76. GRB 100316D: ATCA radio observations
  77. GRB 100319A: correction to GCN 10527
  78. Probable SGR 1833-0832: Swift-XRT refined analysis
  79. Probable SGR 1833-0832: Enhanced Swift-XRT position
  80. Swift-XRT refined position of the probable new SGR 1833-0832
  81. Swift-BAT refined analysis of the probable new SGR 1833-0832
  82. GRB 100219A: MASTER-Net optical alert observations
  83. GRB 100319A: Swift detection of a burst; possible SGR
  84. GRB 100316D: Possible Supernova
  85. GRB 100316D: Pre-burst emission measured by BAT
  86. GRB 100316D: Further Gemini observations
  87. GRB 100219A: optical upper limit
  88. GRB 100316A: optical observations in CrAO
  89. GRB 100316D: Swift/UVOT Observations
  90. GRB 100316D: Swift XRT enhanced position and further refined analysis
  91. GRB 100316B: Swift-XRT refined analysis
  92. Tentative redshift of GRB100316D from X-ray data
  93. GRB 100316C: GROND Detection of a Optical/NIR Afterglow Candidate
  94. Trigger 416226 is probably not a GRB
  95. GRB 100316D: GROND Detection of the Optical/NIR Afterglow Candidate
  96. GRB 100316D: Gemini/GMOS and VLT/X-shooter observations
  97. GRB 100316D: VLT/X-shooter observations
  98. GRB 100316D: Swift-BAT refined analysis
  99. GRB100316C: Swift/UVOT Upper Limits
  100. GRB 100316C: Swift-BAT refined analysis

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