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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"

20571 results found.

  1. GRB 161014A: TSHAO optical observations
  2. GRB 161011A: RATIR Optical and NIR Observations
  3. GRB 161014A: Kanata optical observation
  4. GRB 161010A: Swift/UVOT Possible Detection
  5. GRB 161011A: Swift burst of interest
  6. GRB 161011A: Swift/UVOT Upper Limits
  7. GRB 161010A: Swift-XRT afterglow detection
  8. GRB 161010A: Swift ToO observations
  9. GRB 161007A: NOT optical observations
  10. GRB 161007A: AbAO optical observations
  11. GRB 161007A: Mondy optical observations
  12. GRB 161007A: Swift/UVOT Upper Limits
  13. GRB 161007A: GTC observations
  14. GRB 161004A: Maidanak optical observations
  15. GRB 161004A: refined analysis of TSHAO optical observations
  16. GRB 161007A: MASTER-net early optical observations
  17. GRB 160821A: Maisoncelles observatory optical observations
  18. GRB 160927A: GTC observations
  19. GRB 150302A: late-time imaging and optical afterglow confirmation
  20. GRB 161001A: IRSF upper limits
  21. GRB 161004B: Swift/UVOT Upper Limits
  22. GRB 161004A: RATIR Optical and NIR Observations
  23. GRB 161004A: Swift/UVOT Detection
  24. GRB 161004A: Bassano Bresciano Observatory upper limit
  25. GRB 161004A: TSHAO optical observations
  26. GRB 160927A: 15 GHz upper limits from AMI
  27. GRB 161001A: MASTER-OAFA and MASTER-SAAO early optical observations
  28. GRB 161001A: GROND afterglow candidate
  29. GRB 161001A: X-shooter spectroscopy, candidate host galaxy and redshift
  30. GRB 161001A: Swift/UVOT Upper Limits
  31. Possible radio detection of GRB 160910A with the GMRT
  32. GRB 160927A: Swift/UVOT Upper Limits
  33. GRB 160927A: Bassano Bresciano Observatory optical upper limit
  34. GRB 160927A: NOT optical observations
  35. GRB 160927A: GROND Observations
  36. GRB 160927A: TNG optical afterglow confirmation
  37. GRB 160917A: 15 GHz upper limits from AMI
  38. GRB 160912A: 15 GHz upper limits from AMI
  39. XRT refined analysis for GRB 160925A
  40. GRB 160925A/MASTER optical transient: Mondy optical observations
  41. GRB 160925A: MITSuME Akeno Optical Observations
  42. GRB 160925A: Bassano Bresciano Photometry of MASTER optical transient
  43. GRB 160925A / Fermi 496473540: MASTER OT observations
  44. GRB 160925A: Swift ToO observations
  45. GRB160925A / Fermi 496473540: MASTER optical transient confirmation by LCOGT-FTN
  46. GRB 160925A / Fermi 496473540: Global MASTER Net OT discovery
  47. GRB 160910A: 15 GHz detection from AMI
  48. GRB 160910A: TSHAO optical observations
  49. GRB 160917A: RATIR Optical and NIR Observations
  50. GRB 160917A: Swift/UVOT Detection
  51. GRB 160917A: Mondy optical observations
  52. GRB 160910A: Maidanak optical observations
  53. GRB 160910A: Swift/UVOT Detection
  54. GRB 160912A: RATIR Optical and NIR Observations
  55. GRB 160912A: Swift/UVOT Weak Afterglow Detection
  56. GRB 160912A: Mondy optical observations
  57. GRB 160910A: Mondy optical observations
  58. GRB 160910A: Global MASTER Net OT detection before LAT alert
  59. GRB 160910A: NOT afterglow confirmation
  60. GRB 160910A: Tiled Swift observations
  61. GRB 160910A: Swift-XRT afterglow detection
  62. GRB 160824A: 15 GHz upper limits from AMI
  63. GRB 160821B: 15 GHz upper limits from AMI
  64. GRB 160905A: Swift/UVOT Detection
  65. GRB 160821A: 15 GHz upper limits from AMI
  66. GRB 160816A: Possible radio afterglow detection at 15 GHz with AMI
  67. IceCube HESE 160814: MASTER OT J130845.02-323254.9 as the possible source of the high energy neutrino
  68. GRB 160829A: Swift-XRT observations
  69. GRB 160829A: Swift ToO observations
  70. GRB 160826A: Swift/UVOT Upper Limits
  71. GRB 160825A: not localized by Swift
  72. GRB 160825A: Swift ToO observations
  73. GRB 160824A: ISON/Terskol optical observations
  74. GRB 160824A: Swift/UVOT Possible Afterglow Detection
  75. GRB 160824A: Bassano Bresciano Observatory upper limits
  76. GRB 160821B: VLA 5.0 GHz observations
  77. Possible radio detection of GRB160703A with the GMRT
  78. Possible radio detection of GRB160623A with the GMRT
  79. GRB 160821B: GTC follow-up observation
  80. GRB 160821B: WHT afterglow confirmation and redshift of candidate host
  81. GRB 160821B: Swift/UVOT Upper Limits
  82. Short GRB 160821B: MASTER early optical observations
  83. GRB 160821B: NOT optical afterglow candidate
  84. GRB 160821A: TAROT Calern observatory optical detection
  85. GRB 160821A: Fermi-LAT detection of a bright burst
  86. GRB 160816A: TSHAO optical observations
  87. GRB 160816A: ISON/UAFO optical observations
  88. GRB 160816A: Further RATIR Optical and NIR Observations
  89. Fermi GBM Observations of IceCube-160806A
  90. GRB 160816A: Swift/UVOT Detection
  91. GRB 160804A: 15 GHz detections and upper limit from AMI
  92. GRB 160801A: 15 GHz upper limits from AMI
  93. GRB 160714A: 15 GHz upper limits from AMI
  94. GRB 160816A: RATIR Optical and NIR Observations
  95. GRB 160816A: Swift-XRT afterglow detection
  96. GRB 160816A: MASTER inspection
  97. GRB 160816A: Swift ToO observations
  98. GRB 160815A: Swift/UVOT Detection
  99. IceCube 160806A: Lomonosov BDRG gamma ray prompt observations
  100. Swift Trigger 707545 is likely 4U 1850-03/GS1843-02

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