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"

45943 results found.

  1. GRB 250512B / EP250512a: SVOM/GRM analysis
  2. GRB 250515A: GOTO candidate optical counterpart
  3. MAXI GRB250515.65: Global MASTER-Net observations report
  4. GRB 250515A: Fermi GBM Final Localization
  5. GRB 250424A: COLIBRÍ detection of the associated supernova
  6. Konus-Wind detection of GRB 250512B / EP250512a
  7. GRB 250502A: TESS observations
  8. Fermi trigger No 768922089: Global MASTER-Net observations report
  9. GRB 250511A: GECAM-A detection of a short burst
  10. GRB 250509A: Swift-BAT refined analysis
  11. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Final Epochs)
  12. Fermi GRB 250512A: Global MASTER-Net observations report
  13. Konus-Wind detection of GRB 250506A
  14. EP250512a/GRB 250512B: REM optical/NIR observations
  15. EP250511a: Koshka Zeiss-1000 Optical Upper Limit
  16. GRB 250507B: AstroSat CZTI detection
  17. EP250511a: Gemini optical counterpart observation
  18. EP250512a/GRB 250512B refined analysis of the EP-WXT and EP-FXT observations
  19. EP250512a/GRB 250512B: FTW optical and NIR observations of the counterpart
  20. EP250512a: Global MASTER-Net observations report
  21. EP250511a: FTW optical and NIR observations
  22. GRB 250512B/EP250512a: SVOM/VT optical fading
  23. GRB 250512B/EP250512a：SVOM/VT bright optical counterpart
  24. EP250511a: Mephisto optical upper limits
  25. GRB 250507B: GRBAlpha detection
  26. GRB 250506A: GRBAlpha detection
  27. GRB 250512B: SVOM detection of a burst
  28. GRB 250507B: SVOM/GRM observation of a burst
  29. EP250512a: Einstein Probe detection of an X-ray transient
  30. GRB 250512A: Fermi GBM Final Real-time Localization
  31. EP250511a: REM optical/NIR observations
  32. EP250511a: Einstein Probe follow-up obsevation and refined analysis
  33. EP250511a: SVOM/VT optical candidate comfirmation
  34. EP250511a: Global MASTER-Net observations report
  35. EP250511a: COLIBRÍ optical counterpart candidate
  36. EP250511a: BOOTES-5 optical upper limit
  37. EP250511a: Einstein Probe detection of an X-ray transient
  38. EP250508a: Gemini NIR upper limits
  39. GRB 250510B: Fermi GBM Observation
  40. Fermi GRB 250510C: Global MASTER-Net observations report
  41. Fermi GRB 250510B: Global MASTER-Net observations report
  42. GRB 250510C: Fermi GBM Final Real-time Localization
  43. GRB 250510A: Swift-XRT observations
  44. GRB 250509A: Fermi GBM Observation
  45. IceCube-250506A: No Transient Candidates from the Zwicky Transient Facility
  46. GRB 250510A: follow-up observation with EP-FXT
  47. GRB 250510B: Swift/BAT-GUANO localization skymap of a burst
  48. GRB 250510B: Fermi GBM Final Localization
  49. GRB 250510A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  50. GRB 250509A: Swift-XRT refined Analysis
  51. GRB 250510A: SVOM possible detection of a burst
  52. GRB 250507A: J-band observations with WINTER (duplicate submission)
  53. GRB 250507A: J-band observations with WINTER
  54. EP250508a: SVOM/VT optical candidate fading
  55. GRB 250509A: Enhanced Swift-XRT position
  56. GRB 250509A: Prompt enhanced Swift-XRT position
  57. Fermi GRB 250509A: Global MASTER-Net observations report
  58. Swift GRB 250509A: Global MASTER-Net observations report
  59. GRB 250509A: Swift detection of a burst
  60. GRB 250509A: Fermi GBM Final Real-time Localization
  61. GRB 250506A: NOT optical upper limits
  62. EP250508a: Liverpool Telescope optical upper limits
  63. EP250508a: follow-up observation with EP-FXT
  64. EP250508a: SVOM/VT optical candidate
  65. EP250508a: KAIT optical upper limit
  66. GRB 250507A: KAIT optical upper limit
  67. EP250508a: refined analysis of the EP-WXT and EP-FXT observations
  68. GRB 250505B: SVOM/GRM observation of a short burst
  69. GRB 250502A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  70. GRB 250506A: GECAM detection
  71. EP250508a: REM optical/NIR observations
  72. GRB 250506A: Swift-XRT afterglow detection
  73. EP250508a: Global MASTER-Net observations report
  74. GRB 250506A: SVOM/VT optical upper limit
  75. EP250508a: COLIBRÍ Optical Limit
  76. EP250508a: Einstein Probe detection of an X-ray transient
  77. GRB 250507A: Swift-XRT refined Analysis
  78. IceCube-250506A: Upper limits from a search for additional neutrino events in IceCube
  79. GRB 250506A: Swift/UVOT Upper Limits
  80. GRB 250427B : SVOM detection of a burst through offline search
  81. GRB 250507A: follow-up observation with EP-FXT
  82. GRB 250430A / EP250430a: AstroSat CZTI detection
  83. EP#01709175213/IGR J19566+0326: Swift-XRT detection
  84. GRB 250506A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  85. GRB 250507A: refined SVOM/MXT data analysis
  86. GRB 250507A: REM optical/NIR observations
  87. GRB 250507A: SVOM/VT optical upper limit
  88. GRB 250506A: Swift-XRT observations
  89. Fermi-LAT Gamma-ray Observations of IceCube-250506A
  90. GRB 250507A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  91. EP-WXT trigger 01709175213: a new X-ray outburst of LMXB MAXI J1957+032
  92. GRB 250507A: SVOM detection of a long burst
  93. GRB 250506A: Mephisto optical upper limits
  94. GRB 250504A: EIRSAT-1 GMOD Detection
  95. GRB 250506A: Swift ToO observations
  96. GRB 250502A: Bassano Bresciano Observatory upper limit
  97. IceCube-250506A - IceCube observation of a high-energy neutrino candidate track-like event
  98. IceCube Alert 250506.59: Global MASTER-Net observations report
  99. GRB 250430A: Konus-Wind detection and joint Konus-Wind+Swift-BAT spectral analysis
  100. GRB 250506A: Xinglong 2.16m optical upper limit

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