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"

28201 results found.

  1. GRB 240913A: Fermi GBM Final Real-time Localization
  2. GRB 240912A: J-band observations with WINTER
  3. GRB 240912A: Swift-XRT refined Analysis
  4. GRB 240912A: Fermi GBM Observation
  5. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  6. GRB 240911A: Tiled Swift observations
  7. GRB 240912A : INTEGRAL SPI ACS LIGHT CURVE
  8. GRB 240912B: Fermi GBM Final Real-time Localization
  9. GRB 240912A: NOT optical spectroscopy
  10. GRB 240912A: Enhanced Swift-XRT position
  11. GRB 240912A: Redshift from OSIRIS+/GTC
  12. GRB 240910A: Redshift from OSIRIS+/GTC
  13. GRB 240912A: Swift detection of a burst with an optical counterpart
  14. GRB 240912A: Fermi GBM Final Real-time Localization
  15. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  16. GRB 240910A: JinShan optical observations
  17. GRB 240910A: GOTO candidate optical counterpart
  18. EP240908a: Optical afterglow confirmation
  19. GRB 240910A: Swift ToO observations
  20. IPN triangulation of GRB 240905B (short)
  21. GRB 240825A: 7DT Optical Upper Limit
  22. GRB 240905E: SVOM/VT optical observations
  23. GRB 240910A: GRBAlpha detection
  24. GRB 240910B: Fermi GBM Final Real-time Localization
  25. EP240908a: Updates on the WXT detection result around the trigger time
  26. GRB 240910A: Fermi GBM Final Real-time Localization
  27. EP240908a: optical afterglow candidate
  28. GRB 240905B: GOTO optical upper limits
  29. EP240908a: EP detection of a fast X-ray transient
  30. GRB 240908A: Fermi GBM Final Real-time Localization
  31. GRB 240905E: GIT optical upper limit
  32. GRB 240905B: Swift-XRT observations
  33. GRB 240905E: Gaoyazi/GOT optical upper limits
  34. GRB 240905B: Fermi-LAT detection
  35. GRB 240905B: Swift ToO observations
  36. GRB 240905E: J-band observations with WINTER
  37. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  38. GRB 240905E: AKO Optical Upper Limit
  39. GRB 240905E: SVOM/C-GFT optical upper limit
  40. GRB 240905E: OHP/MISTRAL T193 optical upper limit
  41. GRB 240905E: NOT optical upper limits
  42. GRB 240905E: REM optical/NIR upper limits
  43. GRB 240902B: AstroSat CZTI detection of a long burst
  44. GRB 240905E: Swift-XRT refined Analysis
  45. GRB 240902A: AstroSat CZTI detection of a long burst
  46. GRB 240905E: LCOGT Optical Upper Limit
  47. GRB 240905E: Swift/UVOT Upper Limits
  48. GRB 240905E: SAO RAS optical upper limit
  49. GRB 240825A: Montarrenti Observatory optical follow-up observations
  50. GRB 240905E: Nanshan/HMT optical upper limit
  51. GRB 240905E: Swift detection of a burst
  52. GRB 240819A: Optical upper limits from TESS
  53. GRB 240905D: AstroSat CZTI detection
  54. GRB 240905D: Fermi GBM Final Real-time Localization
  55. GRB 240905B: AstroSat CZTI detection and localization
  56. GRB 240905C: Fermi GBM Final Real-time Localization
  57. GRB 240905B: Fermi GBM Final Real-time Localization
  58. GRB 240825A: ATCA Detection of Radio Counterpart
  59. GRB 240905A: Fermi GBM Final Real-time Localization
  60. GRB 240904A: Swift detection of a burst
  61. GRB 240828A: GECAM detection
  62. GRB 240831B: Fermi GBM Final Localization
  63. GRB 240825A: Magnitude Correction in SVOM/C-GFT Optical Observations
  64. GRB 240825A: MeerLICHT afterglow detection
  65. GRB 240821A: VLT spectroscopic observations
  66. GRB 240825A: TSHAO Optical Upper Limit
  67. GRB 240829B: GRBAlpha detection
  68. GRB240828B: REM optical/NIR upper limits
  69. GRB 240828B: AbAO optical upper limit
  70. GRB 240831A: Fermi GBM Final Real-time Localization
  71. GRB 240828B: Mephisto optical upper limit
  72. GRB 240828B: GRANDMA Optical Upper Limit
  73. GRB 240825A: MeerKAT detection
  74. GRB 240828B: J-band upper limit from WINTER
  75. GRB 240828B: GMG Optical Upper Limit
  76. GRB 240828A: KAIT continued optical observations
  77. GRB 240828B: GWAC-F50A optical upper limit
  78. GRB 240828B: SVOM/C-GFT optical upper limit
  79. GRB 240828B: SAO RAS optical upper limit
  80. GRB 240828B: KAIT optical upper limit
  81. GRB 240829B: Fermi GBM Final Localization
  82. GRB 240828A: Fermi GBM Observation
  83. GRB 240828A: KAIT Optical Afterglow Candidate
  84. GRB 240825A: SVOM/VT optical detection
  85. GRB 240828A: Swift-XRT afterglow detection
  86. GRB 240825A: iTelescope optical observations
  87. GRB 240828B: Swift-XRT afterglow detection
  88. GRB 240829A: Swift detection of a burst
  89. GRB 240828A: Fermi-LAT detection
  90. GRB 240828A: Tiled Swift observations
  91. GRB 240828A: AstroSat CZTI detection of a long burst
  92. GRB 240819A as a likely X-Ray Flash
  93. GRB 240828B: Swift ToO observations
  94. GRB 240825A: VLA detection
  95. SVOM GRB 240821A: optical afterglow discovery
  96. GRB 240828B : Detection of a possible very soft X-ray transient by SVOM/ECLAIRs
  97. GRB 240828A: Fermi GBM Final Real-time Localization
  98. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  99. GRB 240825A: GECAM detection
  100. GRB 240825A: ALMA detection

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