Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

8519 results found.

  1. LIGO/Virgo G296853: BOOTES-1 and GTC optical observations
  2. GRB 170810A: Swift detection of a burst with a bright optical counterpart
  3. LIGO/Virgo G296853: HAWC follow-up
  4. LIGO/Virgo G296853: no INTEGRAL data at the time of the event
  5. LIGO/Virgo G296853: Fermi-LAT search for high-energy gamma-ray counterpart
  6. LIGO/Virgo G296853: Fermi GBM Observations
  7. LIGO/Virgo G296853 ANTARES search
  8. LIGO/Virgo G296853: IceCube neutrino observations
  9. LIGO/Virgo G296853: Identification of a GW Binary Merger Candidate
  10. GRB 170804A: Swift detection of a burst with optical counterpart
  11. Swift Trigger 766161 is not a GRB
  12. GRB 170803A: Swift detection of a burst with an optical counterpart
  13. GRB 170728B: position of the TNG optical counterpart
  14. GRB 170728B: TNG optical afterglow candidate
  15. GRB 170728B: Swift detection of a short burst
  16. Swift triggers on a new galactic source: Swift J181723.1-164300
  17. GRB 170728A: Swift detection of a burst
  18. Trigger 763539 from Swift is probably not astrophysical
  19. GRB 170714A: NOEMA non-detection of the Bastille Day Burst
  20. Correction to GCN Circular 21351: GRB 170714A: Swift/UVOT Observations
  21. GRB 170714A: Swift/UVOT Observations
  22. GRB 170714A: TNG NIR observations
  23. GRB 170714A: z-band afterglow candidate for OSIRIS/GTC
  24. GRB 170714A: Bastille Day Burst: ULGRB or RTDE?
  25. Fermi GBM Detection of possible burst from AXP 4U 0142+61
  26. GRB 170714A: Swift detection of a burst
  27. Correction to GCN Circular 21337: GRB 170710D CALET Gamma-Ray Burst Monitor detection
  28. GRB 170711A: Swift detection of a burst
  29. GRB 170710B: Swift ToO observations
  30. GRB 170710B: Swift detection of a burst
  31. GRB 170710A: Gemini-S candidate counterpart
  32. GRB 170710A: Swift detection of a burst
  33. GRB 170705A: Swift detection of a burst with an optical counterpart
  34. LIGO/Virgo G274296: Updated localization from LIGO data
  35. GRB 170629A: Swift detection of a burst
  36. LIGO/Virgo G270580: Candidate retracted due to H1 data quality
  37. GRB 170626A: TShAO optical observations
  38. GRB 170626A: TNG optical observations
  39. LIGO/Virgo G288732: Fermi GBM Upper Limits for the LIGO Trigger and LAT Candidate
  40. LIGO/Virgo G288732: Pan-STARRS coverage of the Fermi/LAT candidate position
  41. Swift trigger 758168 is probably not an astrophysical source
  42. LIGO/Virgo G288732: VLA imaging of the possible Fermi/LAT counterpart
  43. Swift Trigger 756953 is probably not an astrophysical source
  44. LIGO/Virgo G288732: HAWC follow-up
  45. LIGO/Virgo G288732: UKIRT near-IR imaging of the Fermi/LAT candidate
  46. LIGO/Virgo G288732: LBT optical imaging of the Fermi/LAT candidate
  47. LIGO/Virgo G288732: Updated sky map from gravitational-wave data
  48. LIGO/Virgo G288732: GWFUNC/NOWT observations of the skymap and follow-up of the Fermi/LAT candidate
  49. LIGO/Virgo G288732: INTEGRAL search for a prompt gamma-ray counterpart
  50. LIGO/Virgo G288732: Fermi-LAT detection of a weak candidate
  51. LIGO/Virgo G288732: IceCube neutrino observations update
  52. LIGO/Virgo G288732 ANTARES search
  53. LIGO/VIRGO G288732: Fermi GBM Observations
  54. LIGO/Virgo G288732: Identification of a GW Binary Merger Candidate
  55. GRB 170607A: NOT optical afterglow detection
  56. GRB 170607A: Swift detection of a burst with a bright optical counterpart
  57. GRB 170604A: GTC spectroscopic redshift
  58. Swift Trigger 755873: a possible GRB
  59. GRB 170531A: Swift/UVOT Observations
  60. GRB 170531B: Swift detection of a burst
  61. LIGO/Virgo G268556: VERITAS Very-High-Energy Gamma-Ray Observations
  62. GRB 170526A: Swift detection of a burst
  63. GRB 170524B: Swift ToO observations
  64. GRB 170524A: Swift detection of a burst (or possible new SGR)
  65. GRB 170522A: Tiled Swift observations
  66. GRB 170510A: LCO Siding Springs early observations
  67. GRB 170519A: Swift detection of a burst with an optical counterpart
  68. GRB 170510A: Global MASTER Net possible OT observations
  69. LIGO/Virgo G275404 and G275659: SkyMapper Follow-up Observations
  70. GRB 170510A: LCO possible counterpart
  71. GRB 170510A: Tiled Swift observations
  72. IceCube-170506A - IceCube update on a high-energy neutrino candidate event
  73. LIGO/Virgo G284239:SVOM/Mini-GWAC observations of the initial skymap
  74. LIGO/Virgo G284239: Fermi-LAT search for a high-energy gamma-ray counterpart
  75. LIGO/Virgo: G284239 ANTARES search
  76. LIGO/Virgo G284239: INTEGRAL search for a prompt gamma-ray counterpart
  77. LIGO/Virgo G284239: AGILE MCAL Observations
  78. LIGO/Virgo G284239: IceCube neutrino observations
  79. LIGO/Virgo G284239: Identification of a GW Burst Candidate
  80. GRB 170428A: GTC spectroscopic redshift of candidate host galaxy
  81. LIGO/Virgo G268556: Refined localization from CBC parameter estimation
  82. GRB 170428A: TNG optical observations
  83. GRB 170428A: DCT Imaging
  84. GRB 170428A: RATIR Afterglow Confirmation
  85. GRB 170428A: Xinglong 2.16-m upper limit and host galaxy candidate
  86. Swift Trigger 750337 is probably a noise fluctuation
  87. GRB 170428A: Swift detection of a short burst
  88. Swift trigger 750096 - OT candidate
  89. Swift Trigger 750096 is probably a noise fluctuation
  90. Swift Trigger 750044 is probably a noise fluctuation
  91. GRB 170424A: Tiled Swift observations
  92. Swift Trigger 748858: RATIR Optical and NIR Observations
  93. GRB 170419A: Swift detection of a burst
  94. Swift Trigger 748858: a possible GRB
  95. Trigger 745966: Swift detection of 4U1850-03
  96. GRB 170405A: Swift detection of a burst with an optical counterpart
  97. LIGO/Virgo G275697: Update on significance from offline analyses
  98. LIGO/Virgo G275404: Update on significance from offline analyses
  99. IceCube-170321A: Konus-Wind upper limits
  100. Swift Trigger 745090 is a noise trigger near NGC 5195

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov