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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"

3046 results found.

  1. LIGO/Virgo G298048: Brightening X-ray Emission from GW170817/GRB170817A/SSS17a
  2. LIGO/Virgo G298048: Late-time detection of the X-ray afterglow with Chandra
  3. GRB 171205A: Host galaxy photometric properties
  4. GRB 171205A: Swift-XRT refined Analysis
  5. GRB 171124A: Swift-XRT afterglow detection
  6. INTEGRAL pointed follow-up of IceCube-171106A
  7. GRB 171124A: Swift-XRT observations
  8. GRB 171123A: Swift-XRT refined Analysis
  9. GRB 171120A: Swift-XRT refined Analysis
  10. GRB 171120A: Fermi-LAT detection
  11. GRB 171115A: Swift-XRT refined Analysis
  12. IceCube-171106A: Swift Observations
  13. GRB 171102B: Swift-XRT refined Analysis
  14. GRB 171030A: Swift non-localization with BAT, XRT and UVOT
  15. GRB 171027A: Swift-XRT refined Analysis
  16. Swift Trigger 781740 is not a burst
  17. GRB 171020A: Swift-XRT refined Analysis
  18. GRB 171010B: Swift-XRT afterglow detection
  19. BAT trigger 778435 is not a GRB.
  20. GRB 171010B: Swift-XRT observations
  21. GRB 171010A: Swift-XRT afterglow detection
  22. GRB 171007A: Swift-XRT refined Analysis
  23. GRB 171004A: Swift-XRT refined Analysis
  24. GRB 171001A: Swift-XRT refined Analysis
  25. GRB 171001A: IRSF Observation
  26. Further Swift-XRT observations of IceCube 170922A
  27. IceCube-170922A: Swift-XRT observations
  28. GRB 170921A: Swift-XRT refined Analysis
  29. LIGO/Virgo G297595: NIR Observations following GW170814
  30. GRB 170912A: Swift-XRT refined Analysis
  31. GRB 170912B: Swift-XRT refined Analysis
  32. GRB 170906B: Swift/UVOT Upper Limits
  33. LIGO/Virgo G299232: Swift-XRT sources
  34. GRB 170906A: Swift-XRT refined Analysis
  35. GRB 170906C: Swift-XRT refined Analysis
  36. GRB 170903A: Swift-XRT refined Analysis
  37. LIGO/Virgo G298048: Chandra X-ray Update on GW170817
  38. LIGO/Virgo G298048: Chandra monitoring of the X-ray emission from SSS17a
  39. LIGO/Virgo G298048: Possible Plateau in Ks band revealed by continued Gemini-South observations
  40. LIGO/Virgo G298048: Continued Gemini South observations
  41. LIGO/Virgo G298048: Discovery of X-ray emission from SSS17a in NGC4993
  42. LIGO/Virgo G299232: Further Swift/UVOT Observations of Optical Transient SwiftJ014008.5+343403.6
  43. LIGO/Virgo G299232: Optical Transient Discovery by Swift/UVOT
  44. LIGO/Virgo G298936: HAWC follow-up
  45. GRB 170827A: Swift-XRT refined Analysis
  46. LIGO/Virgo G299232/PGWB170825.55: MASTER Global-Net OT inside NGC1343 discovery
  47. LIGO/Virgo G299232 : Fermi-LAT search for high-energy gamma-ray counterpart
  48. LIGO/Virgo G298389: HAWC follow-up
  49. LIGO/Virgo G297595: INTEGRAL pointed follow-up observations
  50. LIGO/Virgo G298048: INTEGRAL pointed follow-up observations
  51. LIGO/Virgo G298936 : Fermi-LAT search for a high-energy gamma-ray counterpart
  52. GRB 170822A: Swift-XRT refined Analysis
  53. LIGO/Virgo G298389 : Fermi-LAT search for a high-energy gamma-ray counterpart
  54. LIGO/Virgo G298048: Possible X-ray detection with Swift
  55. LIGO/Virgo G298048: optical spectral energy distribution of SSS17a
  56. LIGO/VIRGO G298048: Swift UVOT detection and XRT upper limits
  57. LIGO/Virgo G297595: Swift-XRT sources
  58. LIGO/Virgo G297595 : Fermi-LAT search for high-energy gamma-ray counterpart
  59. GRB 170813A: Swift/UVOT Upper Limits
  60. GRB 170813A: Swift-XRT refined Analysis
  61. GRB 170810A: Swift-XRT refined Analysis
  62. LIGO/Virgo G296853: Fermi-LAT search for high-energy gamma-ray counterpart
  63. GRB 170804A: Swift-XRT refined Analysis
  64. Swift Trigger 766161 is not a GRB
  65. GRB 170803A: Swift-XRT refined Analysis
  66. GRB 170714A: Chandra observations
  67. GRB 170728A: Swift-XRT refined Analysis
  68. GRB 170728B: Swift-XRT refined Analysis
  69. GRB 170714A: Bastille Day Burst: ULGRB or RTDE?
  70. GRB 170714A: Swift-XRT refined Analysis
  71. GRB 170711A: Swift-XRT refined Analysis
  72. GRB 170710B: Fermi GBM observation
  73. GRB 170710B: Swift-XRT and UVOT observations
  74. GRB 170710A: Swift-XRT refined Analysis
  75. GRB 170705A: Swift-XRT refined Analysis
  76. GRB 170629A: Swift-XRT refined Analysis
  77. GRB 170626A: Swift-XRT refined Analysis
  78. LIGO/Virgo G288732: Kiso/KWFC optical imaging of the possible Fermi/LAT counterpart
  79. LIGO/Virgo G288732: Swift/UVOT follow up of the possible LAT counterpart
  80. LIGO/Virgo G288732: Swift-XRT follow up of the putative LAT counterpart
  81. LIGO/Virgo G288732: Fermi-LAT detection of a weak candidate
  82. GRB 170607A: Swift-XRT refined Analysis
  83. Swift trigger 755873: Swift BAT and XRT refined analysis
  84. GRB 170522A: confirmation of the X-ray afterglow
  85. GRB 170604A: Swift-XRT refined Analysis
  86. GRB 170531B: Swift-XRT refined Analysis
  87. GRB 170531A: Swift-XRT refined Analysis
  88. GRB 170524B: Swift-UVOT/XRT Confirmation of Afterglow
  89. GRB 170526A: Swift-XRT refined Analysis
  90. GRB 170524B: Swift-XRT observations
  91. GRB 170524A: Swift-XRT refined Analysis
  92. GRB 170522A: Swift-XRT observations
  93. GRB 170519A: KAIT Optical Observations
  94. GRB 170519A: Swift-XRT refined Analysis
  95. GRB 170510A: Swift-XRT afterglow detection
  96. GRB 170516A: Swift-XRT refined Analysis
  97. GRB 170510A: Swift-XRT observations
  98. Swift XRT observations of GRB 170424A
  99. LIGO/Virgo G284239: Fermi-LAT search for a high-energy gamma-ray counterpart
  100. GRB 170428A: Swift-XRT refined Analysis

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