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"

28225 results found.

  1. GRB 240225B: Swift ToO observations
  2. Konus-Wind detection of GRB 240225B (long)
  3. GRB 240229A: Fermi GBM Final Real-time Localization
  4. GRB 240225B: VLT/X-shooter redshift
  5. GRB 240225B : MITSuME Akeno optical afterglow candidate detection
  6. GRB 240225B: 3.6m DOT observation
  7. GRB 240226A: GRBAlpha detection
  8. GRB 240225B: Mondy afterglow observations
  9. GRB 240225B: Liverpool Telescope afterglow observations
  10. Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up
  11. IPN triangulation of GRB 240227A (short)
  12. GRB 240225B: Liverpool Telescope optical afterglow observations
  13. GRB 240225B: NOT optical observations
  14. GRB 240218A: CMO SAI NIR upper limit
  15. GRB 240227A: Fermi GBM Final Real-time Localization
  16. GRB 240225B: Nanshan/HMT optical afterglow detection
  17. GRB 240225B: CALET Gamma-Ray Burst Monitor detection
  18. GRB 240225B: Swift-XRT observations
  19. GRB 240226B: Fermi GBM Final Real-time Localization
  20. GRB 240225C: CALET Gamma-Ray Burst Monitor detection
  21. GRB 240225B: GOTO detection of a candidate optical afterglow
  22. GRB 240226A: Fermi GBM Final Real-time Localization
  23. Transient EPW20240219aa: REM optical/NIR upper limits
  24. GRB 240225C: GRBAlpha detection
  25. GRB 240222A: ATCA radio observations
  26. GRB 240225C: AstroSat CZTI detection
  27. GRB 240225B: AstroSat CZTI detection
  28. GRB 240225B: Tiled Swift observations
  29. GRB 240225B: MAXI/GSC detection
  30. GRB 240218A: VLA detection
  31. GRB 240225A: Swift/BAT-GUANO detection of a short burst
  32. GRB 240222A: GRBAlpha detection
  33. Transient EPW20240219aa: 7DT Optical Upper Limits
  34. Transient EPW20240219aa: upper limit in gamma-ray range from SPI-ACS/INTEGRAL observations
  35. Insight-HXMT/HE Sub-Threshold Detection of Transient EPW20240219aa
  36. Swift BAT Sub-Threshold Detection of EPW20240219aa
  37. Transient EPW20240219aa: Liverpool Telescope non-detection and limiting magnitude
  38. GRB 240222A: GECAM detection of a burst
  39. GRB 240222A: Swift-XRT refined Analysis
  40. GRB 240222A: Swift/UVOT Upper Limits
  41. Fermi GBM Sub-Threshold Detection of EPW20240219aa as a likely GRB
  42. EPW20240219aa is Likely a GRB Event
  43. GRB 240222A: REM optical and NIR early-time observations
  44. GRB 240222A: Swift detection of a burst
  45. GRB 240222A: Fermi GBM Final Real-time Localization
  46. GRB 240218A: MeerLICHT upper limits
  47. GRB 240216A: Glowbug gamma-ray detection
  48. GRB 240218A: LBT H-band detection
  49. GRB 240220A: Fermi GBM Final Real-time Localization
  50. Konus-Wind detection of GRB 240218A
  51. GRB 240218A: Swift-XRT refined Analysis
  52. GRB 240218A: VLT/X-shooter redshift of z = 6.782
  53. GRB 240218A: Fermi GBM Detection
  54. GRB 240216A: GRBAlpha detection
  55. GRB 240215B: GRBAlpha detection
  56. IPN triangulation of GRB 240209A
  57. GRB 240218A: VLT/FORS2 z-band detection
  58. GRB 240218A: Enhanced Swift-XRT position
  59. GRB 240218A: REM detection of a NIR afterglow candidate
  60. Gamma-ray flaring activity from the blazar 1ES 1959+650 observed by the Fermi-LAT
  61. GRB 240213A: GRBAlpha detection
  62. GRB 240218A : r-band upper limit from Observatoire de Haute-Provence
  63. GRB240218A: VLT/X-shooter upper limits
  64. GRB 240218A: Swift detection of a burst
  65. GRB 240215C: Fermi GBM Final Real-time Localization
  66. GRB 240215B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  67. GRB 240216A: Fermi GBM Final Real-time Localization
  68. GRB 240215A: Tiled Swift observations
  69. GRB 240215A: Swift/BAT-GUANO localization of a burst
  70. GRB 240213A: Glowbug gamma-ray detection
  71. GRB240209A: OHP/T193 detection of the GOTO afterglow candidate AT2024cew / GOTO24pw
  72. GRB 240209A: Wendelstein Optical Observations
  73. GRB 240128A: Further Swift-XRT observations
  74. GRB 240214A: Tiled Swift observations
  75. GRB 240214A/1H 0451-560: MAXI/GSC detection
  76. GRB 240213A: Fermi GBM Final Real-time Localization
  77. GRB 240209A: NOEMA non-detection of AT2024cew / GOTO24pw counterpart candidate
  78. GRB 240209A: NOT photometry of the AT2024cew / GOTO24pw counterpart candidate
  79. GRB 240209A: GOTO optical counterpart candidate
  80. Konus-Wind detection of GRB 240204A
  81. Konus-Wind detection of GRB 240205A (short)
  82. GRB 240209A: Fermi GBM Final Localization
  83. IPN triangulation of GRB 240205A (short)
  84. GRB 240205B: PRIME near infrared detection
  85. GRB 240205A (short): Glowbug gamma-ray detection
  86. GRB240204A: Swift/UVOT Upper Limits
  87. GRB 240205B: AstroSat CZTI detection
  88. Konus-Wind detection of GRB 240205B (long / very soft)
  89. GRB 240207A: Fermi GBM Final Real-time Localization
  90. Konus-Wind detection of GRB 240125A
  91. GRB 240205B: VLT/X-shooter redshift
  92. GRB 240205B: CALET Gamma-Ray Burst Monitor detection
  93. GRB 240205B: BOOTES-6 optical afterglow follow-up
  94. GRB 240205B: ATCA detection of radio counterpart
  95. GRB 240205B: REM detection of the optical/NIR afterglow
  96. GRB 240204A: AstroSat CZTI detection
  97. GRB 240204A: Mondy optical afterglow observations
  98. GRB 240204A : OHP/T193/T120 optical afterglow fading detection
  99. GRB 240205B: GECAM detection of a long burst
  100. GRB 240205B: Skynet Optical Afterglow Observations

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