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"

32535 results found.

  1. GRB 240305A: Fermi GBM observation
  2. Fermi-LAT gamma-ray observations of IceCube-240229A
  3. GRB 240305C: AstroSat CZTI detection of a short burst
  4. Fermi GRB 240305C: Global MASTER-Net observations report
  5. GRB 240305A: Swift/BAT-GUANO arcminute localization of a burst
  6. GRB 240218A: ALMA detection
  7. GRB 240218A: Chandra Detection and Jet Break Confirmation
  8. Konus-Wind detection of GRB 240227A (short/hard)
  9. GRB 240303B: VZLUSAT-2 detection
  10. GRB 240229A: VZLUSAT-2 detection
  11. Improved IPN triangulation of GRB 240227A (short)
  12. IPN triangulation of GRB 240229A
  13. GRB240218A: ATCA observation of the radio counterpart
  14. Transient EPW20240219aa: Optical observations with LDT
  15. Konus-Wind detection of GRB 240303B
  16. Swift Trigger 1218645: Another detection of Swift J151857.0-572147
  17. IPN triangulation of GRB 240303B
  18. Swift J151857.0-572147: Swift-BAT refined analysis
  19. GRB 240303B: Fermi GBM Detection
  20. GRB 240225B: Swift-XRT afterglow detection
  21. Swift detection of Swift J151857.0-572147
  22. GRB 240303B: CALET Gamma-Ray Burst Monitor detection
  23. Swift GRB 240303A: Global MASTER-Net observations report
  24. Swift J151857.0-572147: Confirmation of a new galactic transient
  25. GRB 240225B: Glowbug gamma-ray detection
  26. IceCube-240229A: Upper limits from a search for additional neutrino events in IceCube
  27. GRB 240225C: Glowbug gamma-ray detection
  28. GRB 240225A (short): Glowbug gamma-ray detection
  29. GRB 240229A: DDOTI Upper Limits on the Afterglow
  30. GRB 240218A: NOEMA upper limit
  31. GRB 240229A: CALET Gamma-Ray Burst Monitor detection
  32. GRB 240225B: further SAO RAS optical observations
  33. Fermi GRB 240229A: Global MASTER-Net observations report
  34. GRB 240225B: Swift ToO observations
  35. Konus-Wind detection of GRB 240225B (long)
  36. GRB 240225B: VLT/X-shooter redshift
  37. GRB 240225B : MITSuME Akeno optical afterglow candidate detection
  38. GRB 240225B: 3.6m DOT observation
  39. GRB 240225B: WINTER near-IR observations and upper limits
  40. GRB 240225B: SAO RAS optical observations
  41. GRB 240226A: GRBAlpha detection
  42. GRB 240225B: Mondy afterglow observations
  43. Fermi GRB 240227A: Global MASTER-Net observations report
  44. GRB 240225B: Liverpool Telescope afterglow observations
  45. Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up
  46. IPN triangulation of GRB 240227A (short)
  47. GRB 240225B: Liverpool Telescope optical afterglow observations
  48. GRB 240225B: NOT optical observations
  49. GRB 240218A: CMO SAI NIR upper limit
  50. Fermi GRB 240226A: Global MASTER-Net observations report
  51. Fermi Gamma-ray Burst Monitor trigger 730618809/240226236 is not a GRB
  52. GRB 240225B: Nanshan/HMT optical afterglow detection
  53. GRB 240225B: CALET Gamma-Ray Burst Monitor detection
  54. Transient EPW20240219aa: Kp-band imaging observations with NIRES
  55. Transient EPW20240219aa: J-band upper limits from WINTER
  56. GRB 240225C: CALET Gamma-Ray Burst Monitor detection
  57. GRB 240225B: GOTO detection of a candidate optical afterglow
  58. Transient EPW20240219aa: REM optical/NIR upper limits
  59. GRB 240225C: GRBAlpha detection
  60. GRB 240222A: ATCA radio observations
  61. GRB 240225B: AstroSat CZTI detection
  62. GRB 240225B: Tiled Swift observations
  63. Transient EPW20240219aa: Xinglong-2.16m optical upper limit
  64. GRB 240218A: VLA detection
  65. GRB 240222A: GRBAlpha detection
  66. Transient EPW20240219aa: GECKO: LOAO Optical Upper Limits
  67. Transient EPW20240219aa: 7DT Optical Upper Limits
  68. VLA X-band observation of EPW20240219aa
  69. Transient EPW20240219aa: Mondy optical observations
  70. Transient EPW20240219aa: upper limit in gamma-ray range from SPI-ACS/INTEGRAL observations
  71. Insight-HXMT/HE Sub-Threshold Detection of Transient EPW20240219aa
  72. Swift BAT Sub-Threshold Detection of EPW20240219aa
  73. Transient EPW20240219aa: Liverpool Telescope non-detection and limiting magnitude
  74. GRB 240222A: GECAM detection of a burst
  75. GRB 240222A: Swift-BAT refined analysis
  76. GRB 240222A: Fermi GBM Observation
  77. GRB 240222A: Swift/UVOT Upper Limits
  78. Fermi GBM Sub-Threshold Detection of EPW20240219aa as a likely GRB
  79. Swift GRB 240222A: Global MASTER-Net observations report
  80. Fermi GRB 240222A: Global MASTER-Net observations report
  81. GRB 240222A: REM optical and NIR early-time observations
  82. GRB 240218A: MeerLICHT upper limits
  83. GRB 240216A: Glowbug gamma-ray detection
  84. GRB 240215B: Fermi GBM Observation
  85. GRB 240218A: LBT H-band detection
  86. GRB 240218A: Swift-BAT refined analysis
  87. Fermi GRB 240220A: Global MASTER-Net observations report
  88. Konus-Wind detection of GRB 240218A
  89. GRB 240218A: VLT/X-shooter redshift of z = 6.782
  90. GRB 240218A: Fermi GBM Detection
  91. GRB 240215A: Fermi GBM Observation
  92. GRB 240216A: GRBAlpha detection
  93. GRB 240215B: GRBAlpha detection
  94. IPN triangulation of GRB 240209A
  95. GRB 240218A: VLT/FORS2 z-band detection
  96. GRB 240218A: REM detection of a NIR afterglow candidate
  97. GRB 240213A: GRBAlpha detection
  98. GRB 240218A : r-band upper limit from Observatoire de Haute-Provence
  99. GRB240218A: VLT/X-shooter upper limits
  100. Fermi GRB 240216A: Global MASTER-Net observations report

Advanced

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