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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 171223A; AstroSat CZTI detection
  2. Fermi GBM Trigger 537135776/180108849 is not a GRB
  3. GRB 180103A: AstroSat CZTI detection
  4. GRB 180103A: Swift/UVOT Upper Limits
  5. GRB 180103A: Swift-XRT observations
  6. GRB 171230A CALET Gamma-Ray Burst Monitor detection
  7. GRB 180103A: Swift ToO observations
  8. GRB 180103A: Swift detection of a burst
  9. GRB 171229A CALET Gamma-Ray Burst Monitor detection
  10. GRB 180102A AROMA-N optical observation
  11. VLBA detection of GRB 171205A
  12. GRB 180102A: TSHAO optical upper limit
  13. GRB 180102A: Swift-BAT refined analysis
  14. GRB 180102A: Swift/UVOT Upper Limits
  15. GRB 180102A: NOT optical observations
  16. GRB 180102A: MASTER-Net robotic report
  17. GRB 180102A: Swift-XRT refined Analysis
  18. GRB 180102A: Fermi GBM detection
  19. GRB 180102A: Enhanced Swift-XRT position
  20. GRB 180102A: Prompt enhanced Swift-XRT position
  21. GRB 180102A: Swift detection of a burst
  22. Konus-Wind observation of GRB 171227A
  23. IPN Triangulation of GRB 171227A
  24. GRB 171227A: Fermi GBM detection
  25. GRB 171227A: AGILE/MCAL detection
  26. GRB 171215A: Insight-HXMT/HE detection
  27. GRB 171223A: Insight-HXMT/HE detection
  28. GRB 171212C CALET Gamma-Ray Burst Monitor detection
  29. Konus-Wind observation of GRB 171216B
  30. IceCube-171106A: Konus-Wind upper limits
  31. IceCube-171015A: Konus-Wind upper limits
  32. IceCube-170922A: Konus-Wind upper limits
  33. GRB 171222A: Swift-BAT refined analysis
  34. GRB 171222A: AROMA-N optical observation
  35. GRB 171223A: Fermi GBM detection
  36. GRB 171222A: Fermi GBM detection
  37. GRB 171222A: Nanshan-0.36m optical upper limit
  38. GRB 171222A: Swift/UVOT Upper Limits
  39. GRB 171222A: Nanshan-1m optical afterglow detection
  40. GRB 171222A: MASTER-Net OT observations
  41. GRB 171222A: Redshift from 10.4m GTC/OSIRIS
  42. GRB 171222A: Swift-XRT refined Analysis
  43. GRB 171205A: SMARTS optical/IR supernova monitoring
  44. GRB 171222A: NOT Optical Afterglow
  45. GRB 171216B CALET Gamma-Ray Burst Monitor detection
  46. GRB 171210A CALET Gamma-Ray Burst Monitor detection
  47. GRB 171222A: Enhanced Swift-XRT position
  48. GRB 171222A: Swift detection of a burst
  49. GMRT Radio detection of GRB 171205A
  50. IPN Triangulation of GRB 171216B
  51. GRB 171216A: Swift/UVOT Upper Limits
  52. GRB 171210A: Further Swift-XRT observations
  53. GRB 171216A: Swift-XRT refined Analysis
  54. GRB 171216A: Swift-BAT refined analysis
  55. GRB 171205A: RATAN observations
  56. GRB 171216A: Enhanced Swift-XRT position
  57. GRB 171216A: Swift detection of a burst
  58. Swift Trigger 797070: KAIT Optical Observations
  59. Swift Trigger 797070 is probably not a GRB
  60. GRB 171212A/Swift J1935.7+2036: Swift-BAT refined analysis
  61. GRB 171205A: ALMA observations
  62. GRB 171212A: Swift-XRT refined Analysis
  63. GRB 171211A iTelescope observation
  64. GRB 171212B: Fermi GBM observation
  65. GRB 171212A/Swift J1935.7+2036: Swift/UVOT Upper Limits
  66. GRB 171212B: Fermi-LAT detection
  67. GRB 171212A/Swift J1935.7+2036: TSHAO optical observations
  68. GRB 171212A: Enhanced Swift-XRT position
  69. Konus-Wind observation of GRB 171210A
  70. GRB 171212A: Swift detection of a burst or a Galactic transient
  71. GRB 171205A: JCMT SCUBA-2 sub-mm observations
  72. GRB 171211A: Swift-BAT refined analysis
  73. GRB 171211A: Swift-XRT refined Analysis
  74. GRB 171211A: Swift/UVOT Upper Limits
  75. GRB 171210A: MASTER-Net optical observations
  76. GRB 171209A: MASTER-Net optical observations
  77. GRB 171211A: Enhanced Swift-XRT position
  78. GRB 171210A: Swift-XRT and UVOT observations
  79. GRB 171211A: Swift detection of a possibly short burst
  80. GRB 171210A: Fermi GBM detection
  81. GRB 171210A: Swift ToO observations
  82. Correction to GCN 22184: GRB 171205A: Swift-BAT refined analysis
  83. GRB 171209A: Lulin 1m telescope observations
  84. GRB 171209A: Swift-BAT refined analysis
  85. GRB 171210A: Fermi-LAT detection
  86. Konus-Wind observation of GRB 171205A
  87. GRB 171205A: MASTER-Net OT recent photometry
  88. GRB 171205A: iTelescope optical observations
  89. GRB 171205A: Mondy optical observations
  90. GRB 171205A: SAO-RAS optical observations
  91. GMRT upper limit on GRB 171205A
  92. GRB 171209A: Swift/UVOT Analysis of the burst
  93. Swift trigger 796115 is not astrophysical
  94. GRB 171209A: Swift-XRT refined Analysis
  95. GRB 171209A: Enhanced Swift-XRT position
  96. Swift Trigger 796115 is probably not a GRB
  97. GRB 171205A: VLA detection
  98. GRB 171205A: UKIRT near-IR observations
  99. GRB 171209A: LCO 1-m telescope observations
  100. GRB 171209A: Swift detection of a burst

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