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"

4255 results found.

  1. GRB 240329A: GRBAlpha detection
  2. Fermi trigger No 733366352: Global MASTER-Net observations report
  3. Fermi GRB 240329A: Global MASTER-Net observations report
  4. GRB 240329A: BALROG localization (Fermi Trigger 733441392 / GRB 240329905)
  5. GRB 240329A: Fermi GBM Final Real-time Localization
  6. Fermi GRB 240328B: Global MASTER-Net observations report
  7. Fermi GRB 240328A: Global MASTER-Net observations report
  8. GRB 240320A: Glowbug gamma-ray detection
  9. Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
  10. Fermi trigger No 732657380: Global MASTER-Net observations report
  11. GRB 240320A: Fermi GBM Final Real-time Localization
  12. Fermi GRB 240318A: Global MASTER-Net observations report
  13. Fermi GRB 240317B: Global MASTER-Net observations report
  14. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  15. Fermi trigger No 732299243: Global MASTER-Net observations report
  16. GRB 240315A: Fermi GBM Final Real-time Localization
  17. Fermi trigger No 731839490: Global MASTER-Net observations report
  18. Fermi GRB 240310A: Global MASTER-Net observations report
  19. GRB 240309A: MAXI/GSC detection
  20. GRID detection of GRB 240229A (Updated Report)
  21. GRID detection of GRB 240229A
  22. GRB 240229A: Glowbug gamma-ray detection
  23. GRB 240229A: GRBAlpha detection
  24. Fermi-LAT gamma-ray observations of IceCube-240229A
  25. GRB 240305C: AstroSat CZTI detection of a short burst
  26. GRB 240229A: VZLUSAT-2 detection
  27. Fermi trigger No 731161136: Global MASTER-Net observations report
  28. IceCube-240229A: Upper limits from a search for additional neutrino events in IceCube
  29. GRB 240229A: CALET Gamma-Ray Burst Monitor detection
  30. IceCube-240229A - IceCube observation of a high-energy neutrino candidate track-like event
  31. GRB 240225B: further SAO RAS optical observations
  32. Fermi GRB 240229A: Global MASTER-Net observations report
  33. IceCube Alert 240229.66: Global MASTER-Net observations report
  34. GRB 240229A: BALROG localization (Fermi Trigger 730908432 / GRB 240229588)
  35. GRB 240229A: Fermi GBM Final Real-time Localization
  36. GRB 240225B: VLT/X-shooter redshift
  37. GRB 240225B: 3.6m DOT observation
  38. GRB 240225B: MAXI/GSC detection
  39. Transient EPW20240219aa: Mondy optical observations
  40. Fermi trigger No 729914426: Global MASTER-Net observations report
  41. Gamma-ray flaring activity from the blazar 1ES 1959+650 observed by the Fermi-LAT
  42. Fermi trigger No 729650855: Global MASTER-Net observations report
  43. Fermi GRB 240213A: Global MASTER-Net observations report
  44. Fermi trigger No 729152364: Global MASTER-Net observations report
  45. Fermi trigger No 729012023: Global MASTER-Net observations report
  46. GRB 240204A: Mondy optical afterglow observations
  47. Fermi trigger No 728749569: Global MASTER-Net observations report
  48. GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
  49. Fermi GRB 240204A: Global MASTER-Net observations report
  50. Fermi trigger No 728706420: Global MASTER-Net observations report
  51. IceCube Alert 240204.38: Global MASTER-Net observations report
  52. GRB 240129A: Fermi GBM Observation
  53. Fermi GRB 240127A: Global MASTER-Net observations report
  54. Konus-Wind detection of GRB 240119A (short/hard)
  55. IPN triangulation of GRB 240119A (short)
  56. GRB 240119A: GECAM detection of a short burst
  57. GRB 240119A: AstroSat CZTI detection of a short burst
  58. GRB 240118A: Mondy optical observations
  59. GRB 240119A: Fermi GBM Final Localization
  60. GRID detection of GRB 231230A
  61. IPN triangulation of GRB 240112A (long)
  62. GRB 240112C: Swift/UVOT Detection
  63. Fermi trigger No 726773850: Global MASTER-Net observations report
  64. GRB 240112C: Swift-XRT refined Analysis
  65. Fermi trigger No 726774492: Global MASTER-Net observations report
  66. GRB 240112C: Swift detection of a burst with an optical counterpart
  67. GRB 240112A: GECAM detection of a burst
  68. GRB 230812B: further radio observations with the VLA
  69. GRB 240107A: MAXI/GSC detection
  70. LIGO/Virgo/KAGRA S240107b: Identification of a GW compact binary merger candidate
  71. IceCube-Cascade 231230A: Upper limits from a search for additional neutrino events in IceCube
  72. Fermi trigger No 725806648: Global MASTER-Net observations report
  73. GRB231230A: Fermi GBM Observation
  74. Fermi trigger No 725592555: Global MASTER-Net observations report
  75. GRB 231230A: Swift detection of a burst
  76. GRB 231230A: Fermi GBM Final Real-time Localization
  77. Fermi trigger No 724781422: Global MASTER-Net observations report
  78. GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
  79. GRB 231205B: VZLUSAT-2 detection
  80. Konus-Wind detection of GRB 231210B
  81. Swift GRB231215.41: Global MASTER-Net observations report
  82. Fermi trigger No 724278269: Global MASTER-Net observations report
  83. GRB 231210B: Swift detection of a burst with optical counterpart
  84. IPN triangulation of GRB 231129C
  85. GRB 231208A: GRBAlpha detection
  86. GRB 231208A: Glowbug gamma-ray detection
  87. GRB 231208A: AstroSat CZTI detection of a faint burst
  88. GRB 231205B: REM optical/NIR upper limits
  89. GRB 231129C: ASIM MXGS observation and localization
  90. GRB 231205B: NUTTelA-TAO / BSTI Early Optical Limits
  91. GRB 231205B : MITSuME Akeno optical upper limits
  92. Fermi trigger No 723435916: Global MASTER-Net observations report
  93. Fermi trigger No 723326169: Global MASTER-Net observations report
  94. Fermi trigger No 723149952: Global MASTER-Net observations report
  95. GRB 231129A: VZLUSAT-2 detection
  96. GRB 231129C: AGILE detection
  97. GRB 231129A : MITSuME Akeno optical upper limits
  98. GRB 231129C: MASTER OT detection
  99. GRB 231129A: BOOTES-5/JGT optical upper limit
  100. GRB 231129C: Fermi-LAT detection

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov