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"

21980 results found.

  1. EP240913a: EP-WXT detection of a fast X-ray transient
  2. GRB 240911A: LCO optical observations
  3. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  4. GRB 240912A: Swift/UVOT Detection
  5. GRB 240911A: GOTO optical limits on Swift/XRT candidates
  6. Fermi trigger No 747920561: Global MASTER-Net observations report
  7. GRB 240911A: Swift-XRT observations
  8. Fermi GRB 240913A: Global MASTER-Net observations report
  9. GRB 240912A: J-band observations with WINTER
  10. Swift GRB 240912A: Global MASTER-Net observations report
  11. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  12. GRB 240911A: Tiled Swift observations
  13. GRB 240912A : INTEGRAL SPI ACS LIGHT CURVE
  14. GRB 240912A: Redshift from OSIRIS+/GTC
  15. Fast X-ray Transient EP240801a: GMRT radio observations
  16. GRB 240910A: NOT optical observations
  17. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  18. GRB 240910A: JinShan optical observations
  19. GRB 240910A: GOTO candidate optical counterpart
  20. EP240908a: Optical afterglow confirmation
  21. GRB 240910A: Swift ToO observations
  22. GRB 240825A: 7DT Optical Upper Limit
  23. GRB 240905E: SVOM/VT optical observations
  24. GRB 240905E: SVOM/VT optical observations (duplicate submission of GCN 37453)
  25. LIGO/Virgo/KAGRA S240910ci: NED Galaxies in the Localization Volume
  26. LIGO/Virgo/KAGRA S240910ci: Coverage and upper limits from MAXI/GSC observations
  27. EP240908a: Mondy and AbAO follow-up observations
  28. EP240908a: Updates on the WXT detection result around the trigger time
  29. Fermi GRB 240910A: Global MASTER-Net observations report
  30. LIGO/Virgo/KAGRA S240908bs: Upper limits from Swift/BAT-GUANO
  31. LIGO/Virgo/KAGRA S240907cg: Upper limits from Swift/BAT-GUANO
  32. EP240908a: optical afterglow candidate
  33. EP EP240908a: Global MASTER-Net observations report
  34. Fermi trigger No 747553301: Global MASTER-Net observations report
  35. EP240908a: TRT optical upper limit
  36. GRB 240905B: GOTO optical upper limits
  37. EP240908a: EP detection of a fast X-ray transient
  38. Fermi GRB 240908A: Global MASTER-Net observations report
  39. GRB 240905E: GIT optical upper limit
  40. GRB 240905B: Swift-XRT observations
  41. GRB 240905E: Gaoyazi/GOT optical upper limits
  42. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  43. GRB 240905B: Swift ToO observations
  44. GRB 240905E: J-band observations with WINTER
  45. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  46. Fermi GRB 240905D: Global MASTER-Net observations report
  47. Fermi GRB 240905A: Global MASTER-Net observations report
  48. GRB 240905E: REM optical/NIR upper limits
  49. GRB 240905E: Swift/UVOT Upper Limits
  50. GRB 240905E: SAO RAS optical upper limit
  51. GRB 240825A: Montarrenti Observatory optical follow-up observations
  52. GRB 240905E: Nanshan/HMT optical upper limit
  53. Swift GRB 240905E: Global MASTER-Net observations report
  54. Fermi GRB 240905B: Global MASTER-Net observations report
  55. GRB 240825A: ATCA Detection of Radio Counterpart
  56. Swift GRB 240904A: Global MASTER-Net observations report
  57. Fermi trigger No 747163821: Global MASTER-Net observations report
  58. LIGO/Virgo/KAGRA S240825ar: Upper limits from Swift/BAT-GUANO
  59. LIGO/Virgo/KAGRA S240807h: Upper limits from Swift/BAT-GUANO
  60. GRB 240825A: Magnitude Correction in SVOM/C-GFT Optical Observations
  61. GRB 240825A: MeerLICHT afterglow detection
  62. Fermi trigger No 746923430: Global MASTER-Net observations report
  63. GRB 240828A: SAO RAS AS-500(2) optical observations
  64. GRB 240821A: VLT spectroscopic observations
  65. Fermi trigger No 746882332: Global MASTER-Net observations report
  66. GRB240828B: REM optical/NIR upper limits
  67. Fermi trigger No 746816563: Global MASTER-Net observations report
  68. GRB 240825A: SOAR observations
  69. GRB 240828B: Mephisto optical upper limit
  70. GRB 240828B: GRANDMA Optical Upper Limit
  71. LIGO/Virgo/KAGRA S240830gn: Coverage and upper limits from MAXI/GSC observations
  72. GRB 240825A: MeerKAT detection
  73. GRB 240828B: J-band upper limit from WINTER
  74. Fermi trigger No 746684112: Global MASTER-Net observations report
  75. GRB 240828A: KAIT continued optical observations
  76. GRB 240828B: SAO RAS optical upper limit
  77. GRB 240828A: SAO RAS optical observations
  78. Fermi trigger No 746587425: Global MASTER-Net observations report
  79. GRB 240828A: KAIT Optical Afterglow Candidate
  80. GRB 240825A: SVOM/VT optical detection
  81. GRB 240828A: Swift-XRT afterglow detection
  82. GRB 240825A: further SAO RAS optical observations
  83. GRB 240825A: iTelescope optical observations
  84. GRB 240828B: Swift-XRT afterglow detection
  85. Swift GRB240829.16: Global MASTER-Net observations report
  86. GRB 240828A: Tiled Swift observations
  87. LAT GRB240828.62: Global MASTER-Net observations report
  88. Fermi GRB 240828A: Bassano Bresciano Observatory upper limit
  89. GRB 240819A as a likely X-Ray Flash
  90. GRB 240828B: Swift ToO observations
  91. GRB 240821A: PRIME near-infrared observations
  92. GRB 240825A: VLA detection
  93. Fermi GRB 240828A: Global MASTER-Net observations report
  94. Fermi trigger No 746438824: Global MASTER-Net observations report
  95. SVOM GRB 240821A: optical afterglow discovery
  96. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  97. GRB 240825A: ALMA detection
  98. GRB 240825A: SAO RAS optical observations
  99. GRB 240824A: GIT optical upper limit
  100. GRB 240825A: TNG optical photometry and spectroscopy

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