Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

11522 results found.

  1. 191017A: BALROG localization (Fermi Trigger 592997024 / GRB 191017391)
  2. Fermi trigger No 592818648: Global MASTER-Net observations report
  3. ANTARES 191011A: AMON + ANTARES Identification of a High-Energy Neutrino + Fermi LAT Coincidence
  4. GRB 191009A: AstroSat CZTI detection
  5. GRB 191011A: Swift/UVOT Detection
  6. GRB 191011A: Fermi GBM observation
  7. GRB 19011A: Optical Afterglow Detection with LCO
  8. GRB 191009A: Insight-HXMT/HE detection
  9. GRB 191011A: BALROG localization (Fermi Trigger 592461363 / GRB 191011192)
  10. GRB 191011A: VLT X-shooter redshift from RRM Observations
  11. GRB 191011A: Fermi GBM Final Real-time Localization
  12. GRB 191009A: BALROG localization (Fermi Trigger 592297741 / GRB 191009298)
  13. GRB 191009A: Fermi GBM Final Real-time Localization
  14. Fermi trigger No 592211224: Global MASTER-Net observations report
  15. Fermi trigger No 592211224: Global MASTER-Net observations report
  16. GRB 191008A: Fermi GBM Final Real-time Localization
  17. Fermi/GBM observation of a bright burst from magnetar SGR 1935+2154
  18. GRB 191001A: Swift-XRT observations
  19. GRB 191001A: Fermi GBM observation
  20. GRB 190919A: AstroSat CZTI detection
  21. Fermi-LAT Gamma-ray Observations of IceCube-191001A
  22. IceCube-191001A: Not observable by Fermi-GBM
  23. IPN triangulation of GRB 191001A
  24. GRB 191001A: Swift ToO observations
  25. GRB 191001A: KAIT Optical Upper Limit
  26. GRB 191001A: RATIR Optical and NIR Observations
  27. IceCube-191001A - IceCube observation of a high-energy neutrino candidate event
  28. GRB 191001A: DDOTI Optical Counterpart Candidate
  29. LIGO/Virgo S190930t: No counterpart candidates in Fermi-LAT observations
  30. Fermi trigger No 591604915: Global MASTER-Net observations report
  31. LIGO/Virgo S190930s: No counterpart candidates in Fermi-LAT observations
  32. GRB 191001A: BALROG localization (Fermi Trigger 591604915 / GRB 191001279)
  33. GRB 191001A: Fermi GBM Final Real-time Localization
  34. LIGO/Virgo S190930t: Upper limits from Fermi-GBM Observations
  35. LIGO/Virgo S190930s: Upper limits from Fermi-GBM Observations
  36. GRB 190928A: Insight-HXMT/HE detection
  37. Fermi trigger No 591532362: Global MASTER-Net observations report
  38. GRB 190930A: Fermi GBM Final Real-time Localization
  39. IPN triangulation of GRB 190928A (long/bright)
  40. Fermi trigger No 591391412: Global MASTER-Net observations report
  41. Fermi trigger No 591321287: Global MASTER-Net observations report
  42. LIGO/Virgo S190924h: No counterpart candidates in Fermi-LAT observations
  43. LIGO/Virgo S190924h: Upper limits from Fermi-GBM Observations
  44. Fermi-LAT Gamma-ray Observations of IceCube-190922B
  45. LIGO/Virgo S190923y: No counterpart candidates in Fermi-LAT observations
  46. Fermi-LAT Gamma-ray Observations of IceCube-190922A
  47. LIGO/Virgo S190923y: Upper limits from Fermi-GBM Observations
  48. GRB 190923A: BALROG localization (Fermi Trigger 590942887 / GRB 190923617)
  49. GRB 190923A: Fermi GBM Final Real-time Localization
  50. Fermi trigger No 590899086: Global MASTER-Net observations report
  51. IceCube-190922B: Upper limits from Fermi-GBM Observations
  52. IceCube-190922A: Upper limits from Fermi-GBM Observations
  53. IceCube-190922B - IceCube observation of a high-energy neutrino candidate event
  54. IceCube-190922A - IceCube observation of a high-energy neutrino candidate event
  55. Fermi trigger No 590777160: Global MASTER-Net observations report
  56. GRB 190921A: Fermi GBM Final Real-time Localization
  57. GRB 190919B: LCO Optical Afterglow Detection
  58. Fermi trigger No 590621700: Global MASTER-Net observations report
  59. Fermi trigger No 590610007: Global MASTER-Net observations report
  60. GRB 190919A: Fermi GBM Final Real-time Localization
  61. HAWC-190916A: Upper limits from Fermi-GBM Observations
  62. GRB 190828B: AstroSat CZTI detection
  63. Fermi trigger No 590335819: Global MASTER-Net observations report
  64. LIGO/Virgo S190915ak: Upper limits from Fermi-GBM Observations
  65. LIGO/Virgo S190915ak: No counterpart candidates in Fermi-LAT observations
  66. GRB 190916A: Fermi GBM Final Real-time Localization
  67. GRB 190915A: Insight-HXMT/HE detection
  68. GRB190915A: MASTER optical observation of BALROG Fermi GRB localization
  69. GRB 190915A: BALROG localization (Fermi Trigger 590219102 / GRB 190915240)
  70. GRB 190915A: Fermi GBM Final Real-time Localization
  71. GRB 190914A: Fermi GBM Final Real-time Localization
  72. GRB 190828C: AstroSat CZTI detection
  73. Fermi trigger No 590038994: Global MASTER-Net observations report
  74. LIGO/Virgo S190910h: No counterpart candidates in Fermi-LAT observations
  75. GRB 190913A: Fermi GBM Final Real-time Localization
  76. Update to the Fermi GBM Localizations
  77. LIGO/Virgo S190910d: No counterpart candidates in Fermi-LAT observations
  78. LIGO/Virgo S190910h: Upper limits from Fermi-GBM Observations
  79. LIGO/Virgo S190910d: Upper limits from Fermi-GBM Observations
  80. GRB 190910A: Fermi GBM Final Real-time Localization
  81. GRB 190901A: AstroSat CZTI detection
  82. ZTF19abvizsw/AT2019pim, search for GRB in SPI-ACS/INTEGRAL data
  83. Fermi trigger No 589561732 Global MASTER-Net observations report
  84. GRB 190829A observations in CrAO, photometry of the SN
  85. Fermi trigger No 589487114 Global MASTER-Net observations report
  86. GRB 190906B: Fermi GBM Final Real-time Localization
  87. GRB 190829A: GTC confirmation of an associated Type Ic-BL Supernova
  88. GRB 190829A: ATCA cm-band detection
  89. Fermi trigger No 589419513 Global MASTER-Net observations report
  90. GRB 190905A: Fermi GBM Final Real-time Localization
  91. Fermi GBM GCN 25668 Retraction
  92. GRB190829A: Keck LRIS spectroscopic confirmation of the accompanying supernova
  93. IPN triangulation of GRB 190903A (short)
  94. Konus-Wind observation of GRB 190829A
  95. GRB 190829A: MASTER confirmation of GROND SN
  96. GRB 190901A: Insight-HXMT/HE detection
  97. Fermi trigger No 589263065 Global MASTER-Net observations report
  98. Liverpool Telescope observations of ZTF19abvizsw, a candidate untriggered GRB afterglow
  99. GRB 190904A: Fermi GBM Final Real-time Localization
  100. GRB 190829A: LCO Optical Afterglow Detection

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