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"

12095 results found.

  1. Fermi trigger No 723906955: Global MASTER-Net observations report
  2. GRB 231208A: AstroSat CZTI detection of a faint burst
  3. Fermi trigger No 723581802: Global MASTER-Net observations report
  4. GRB 231205B: Ondrejov D50 optical upper limit
  5. Fermi-LAT gamma-ray observations of IceCube-231202A
  6. GRB 231205B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
  7. GRB 231206A: GECAM-B detection of a short burst (correction)
  8. GRB 231206A: GECAM-B detection of a short burst
  9. GRB 231205B: Nanshan/HMT optical upper limit
  10. GRB 231205B: GECAM-B detection of a long burst
  11. GRB 231204A: Glowbug gamma-ray detection
  12. GRB 231204A: CALET Gamma-Ray Burst Monitor detection
  13. Fermi-LAT daily aperture light curve of T CrB now available
  14. GRB 231204A: AstroSat CZTI detection
  15. GRB 231205A: GECAM-B detection of a short burst
  16. Fermi trigger No 723435916: Global MASTER-Net observations report
  17. Fermi trigger No 723326169: Global MASTER-Net observations report
  18. LIGO/Virgo/KAGRA S231129ac: Upper limits from Swift/BAT-GUANO
  19. Fermi trigger No 723412808: Global MASTER-Net observations report
  20. GRB 231204A: Fermi GBM Final Real-time Localization
  21. GRB 231203A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  22. Konus-Wind detection of GRB 231129C
  23. Fermi trigger No 723149952: Global MASTER-Net observations report
  24. GRB 231129C: Swift/BAT-GUANO localization of a burst outside the coded FOV
  25. GRB 231129C: Fermi-LAT detection
  26. GRB 231129C: GECAM-B detection of a bright burst
  27. GRB 231129C: AstroSat CZTI detection
  28. GRB 231127A: GRBAlpha detection
  29. GRB 231129C: MAXI/GSC detection
  30. Fermi trigger No 722977823: Global MASTER-Net observations report
  31. GRB 231129B: MAXI/GSC detection
  32. Fermi-LAT gamma-ray observations of IceCube-231125A
  33. GRB 231129A: GECAM-C detection of a long burst
  34. GRB 231129A: INTEGRAL detection of a long GRB
  35. GRB 231127A: AstroSat CZTI detection
  36. GRB 231123B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  37. GRB 231124A: GRBAlpha detection
  38. GRB 231125A: AstroSat CZTI detection of a short burst
  39. GRB 231111A: Optical follow-up observations at Terskol, AbAO, Maidanak, Mondy, Assy
  40. GRB230506B: VIRT optical upper limit
  41. Fermi trigger No 722462310: Global MASTER-Net observations report
  42. GRB 231115A: XMM-Newton observation
  43. GRB 231123A: AstroSat CZTI detection
  44. GRB 231117A: Mondy optical observations
  45. GRB 231118A: REM optical afterglow detection
  46. GRB 231122B: AstroSat CZTI detection
  47. GRB 231122B: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  48. GRB 231117A: Continued GTC Observations
  49. Fermi trigger No 722349867: Global MASTER-Net observations report
  50. GRB 231122A: GECAM detection
  51. GRB 231122B: GECAM detection
  52. GRB 231118A: ATCA detection of radio counterpart
  53. LIGO/Virgo/KAGRA S231118d: Upper limits from Swift/BAT-GUANO
  54. LIGO/Virgo/KAGRA S231118an: Upper limits from Swift/BAT-GUANO
  55. LIGO/Virgo/KAGRA S231114n: Upper limits from Swift/BAT-GUANO
  56. LIGO/Virgo/KAGRA S231113bb: Upper limits from Swift/BAT-GUANO
  57. Konus-Wind detection of GRB 231020A
  58. GRB 231117A: LDT Confirmation of Optical Fading
  59. 231118A: Swift-UVOT Detection
  60. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
  61. GRB 231120A: Fermi GBM Final Real-time Localization
  62. GRB 231117A: Swift-XRT refined Analysis
  63. GRB 231118A: Swift-XRT refined Analysis
  64. GRB 231118A: AstroSat CZTI detection
  65. GRB 231118A: LCOGT Optical Observations
  66. GRB 231118A: MASTER OT observation
  67. Swift GRB231118.72: Global MASTER-Net observations report
  68. GRB 231115A: JinShan optical upper limits
  69. Konus-Wind detection of GRB 231117A (short/hard)
  70. GRB 231115A: optical observations from INAF observatories
  71. GRB 231117A: AGILE detection of a bright short burst
  72. GRB 231117A: AstroSat CZTI detection of a bright short burst
  73. GRB 231115A: Non-detection of radio emission with CHIME/FRB
  74. GRB 231111A: Swift/UVOT Detection
  75. GRB 231115A: Swift/BAT-GUANO detection of a short burst
  76. Konus-Wind detection of GRB 231115A (a probable Magnetar Giant Flare from M82)
  77. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
  78. GRB 231115A: Kinder observations with Lulin observatory
  79. GRB231115A: GRANDMA Observations
  80. GECAM-B observation of a short burst from SGR J1555-5402
  81. LIGO/Virgo S231113bw: upper limits from AGILE/MCAL
  82. SGRJ1555-5402: Swift/BAT-GUANO arcminute localization of a SGR flare
  83. LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
  84. LIGO/Virgo/KAGRA S231113bw: Coverage and upper limits from MAXI/GSC observations
  85. LIGO/Virgo/KAGRA S231113bw: Identification of a GW compact binary merger candidate
  86. GRB 231111A: Afterglow redshift from OSIRIS+/GTC
  87. GRB 231110A: AstroSat CZTI detection
  88. GRB 231111A: Leavitt Observatory optical observations
  89. GRB 231111A: Osservatorio Astronomico "Nastro Verde" optical observations with detection of an optical counterpart
  90. GRB 231111A: GECAM-C detection of a long burst (correction)
  91. GRB 231110A: GECAM-B detection (correction)
  92. GRB 231111A: GECAM-C detection of a long burst
  93. GRB 231110A: GECAM detection
  94. GRB 231111A: Swift detection of a burst with an optical counterpart
  95. Swift GRB231111.60: Global MASTER-Net observations report
  96. Swift GRB231110.89: Global MASTER-Net observations report
  97. GRB 231110A: Swift detection of a burst
  98. Fermi GRB 231108A: Global MASTER-Net observations report
  99. Fermi trigger No 721006392: Global MASTER-Net observations report
  100. LIGO/Virgo/KAGRA S231102w: Upper limits from Swift/BAT-GUANO

Advanced

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