Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. 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"

36398 results found.

  1. GRB 240912A: Swift-XRT refined Analysis
  2. GRB 240912A: Fermi GBM Observation
  3. Swift GRB 240912A: Global MASTER-Net observations report
  4. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  5. GRB 240911A: Tiled Swift observations
  6. Fermi Gamma-ray Burst Monitor trigger 747839931/240912555 is not a GRB
  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: Fermi GBM Observation
  16. GRB 240910A: NOT optical observations
  17. GRB 240911A : a likely weak GRB detected by SVOM/ECLAIRs
  18. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  19. GRB 240910A: JinShan optical observations
  20. GRB 240910A: GOTO candidate optical counterpart
  21. GRB 240710A: SVOM/GRM observation
  22. GRB 240910A: Swift ToO observations
  23. IPN triangulation of GRB 240905B (short)
  24. GRB 240825A: 7DT Optical Upper Limit
  25. GRB 240905E: SVOM/VT optical observations
  26. GRB 240905E: SVOM/VT optical observations (duplicate submission of GCN 37453)
  27. GRB 240910A: GRBAlpha detection
  28. GRB 240910B: Fermi GBM Final Real-time Localization
  29. GRB 240910A: SVOM/GRM observation
  30. EP240908a: Mondy and AbAO follow-up observations
  31. Fermi GRB 240910A: Global MASTER-Net observations report
  32. GRB 240910A: Fermi GBM Final Real-time Localization
  33. LIGO/Virgo/KAGRA S240908bs: Upper limits from Swift/BAT-GUANO
  34. LIGO/Virgo/KAGRA S240907cg: Upper limits from Swift/BAT-GUANO
  35. GRB 240905B: Fermi GBM Observation
  36. GRB 240905B: GOTO optical upper limits
  37. Fermi GRB 240908A: Global MASTER-Net observations report
  38. GRB 240908A: Fermi GBM Final Real-time Localization
  39. GRB 240801A: SVOM/GRM observation
  40. GRB 240905E: GIT optical upper limit
  41. GRB 240905B: Swift-XRT observations
  42. GRB 240905E: Gaoyazi/GOT optical upper limits
  43. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  44. GRB 240905B: Fermi-LAT detection
  45. GRB 240905B: Swift ToO observations
  46. GRB 240905E: J-band observations with WINTER
  47. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  48. GRB 240905E: AKO Optical Upper Limit
  49. GRB 240905E: SVOM/C-GFT optical upper limit
  50. GRB 240905E: OHP/MISTRAL T193 optical upper limit
  51. Fermi GRB 240905D: Global MASTER-Net observations report
  52. Fermi GRB 240905A: Global MASTER-Net observations report
  53. GRB 240905E: NOT optical upper limits
  54. GRB 240905E: REM optical/NIR upper limits
  55. GRB 240902B: AstroSat CZTI detection of a long burst
  56. GRB 240905E: Swift-XRT refined Analysis
  57. GRB 240902A: AstroSat CZTI detection of a long burst
  58. GRB 240905E: SVOM/GRM observation
  59. GRB 240905E: LCOGT Optical Upper Limit
  60. GRB 240905E: Swift/UVOT Upper Limits
  61. GRB 240905E: SAO RAS optical upper limit
  62. GRB 240825A: Montarrenti Observatory optical follow-up observations
  63. GRB 240905E: Nanshan/HMT optical upper limit
  64. Swift GRB 240905E: Global MASTER-Net observations report
  65. GRB 240905E: Swift detection of a burst
  66. GRB 240819A: Optical upper limits from TESS
  67. GRB 240905D: AstroSat CZTI detection
  68. GRB 240905A: SVOM/GRM observation
  69. Fermi GRB 240905B: Global MASTER-Net observations report
  70. GRB 240905D: Fermi GBM Final Real-time Localization
  71. GRB 240905B: AstroSat CZTI detection and localization
  72. GRB 240905C: Fermi GBM Final Real-time Localization
  73. GRB 240905B: Fermi GBM Final Real-time Localization
  74. GRB 240825A: ATCA Detection of Radio Counterpart
  75. Swift GRB 240904A: Global MASTER-Net observations report
  76. GRB 240905A: Fermi GBM Final Real-time Localization
  77. Fermi Gamma-ray Burst Monitor trigger 747163821/240904729 is not a GRB
  78. GRB 240904A: Swift detection of a burst
  79. GRB 240828A: SVOM/GRM observation
  80. LIGO/Virgo/KAGRA S240825ar: Upper limits from Swift/BAT-GUANO
  81. LIGO/Virgo/KAGRA S240807h: Upper limits from Swift/BAT-GUANO
  82. Fermi Gamma-ray Burst Monitor trigger 240831A is not a GRB
  83. GRB 240828A: GECAM detection
  84. GRB 240831B: Fermi GBM Final Localization
  85. Fermi Gamma-ray Burst Monitor trigger 746882332/240901471 is not a GRB
  86. GRB 240825A: Magnitude Correction in SVOM/C-GFT Optical Observations
  87. GRB 240825A: MeerLICHT afterglow detection
  88. GRB 240828A: SAO RAS AS-500(2) optical observations
  89. GRB 240821A: VLT spectroscopic observations
  90. GRB 240825A: TSHAO Optical Upper Limit
  91. GRB 240829B: GRBAlpha detection
  92. GRB240828B: REM optical/NIR upper limits
  93. GRB 240828B: AbAO optical upper limit
  94. GRB 240831A: Fermi GBM Final Real-time Localization
  95. GRB 240825A: SOAR observations
  96. GRB 240828B: Mephisto optical upper limit
  97. GRB 240828B: GRANDMA Optical Upper Limit
  98. GRB 240829A: Swift-BAT refined analysis
  99. GRB 240825A: Swift-BAT refined analysis
  100. GRB 240825A: MeerKAT 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