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"

21982 results found.

  1. Fermi GRB 240619A: Global MASTER-Net observations report
  2. EP240617a: STEP/T80S optical limits
  3. GRB 240615A: possible transient detection from Wendelstein observations
  4. LIGO/Virgo S240615dg: GRANDMA/FRAM-CTA-N Observations
  5. EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
  6. LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
  7. Fermi trigger No 740430582: Global MASTER-Net observations report
  8. EP240617a: EP-WXT detection of a fast X-ray transient
  9. EP240618a: EP-WXT detection of a fast X-ray transient and EP-FXT quick follow-up
  10. LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
  11. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  12. GRB 240615A: J-band upper limits from WINTER
  13. GRB 240615A: Swift-XRT observations
  14. X-ray transient EP240414a: Chandra late time observation
  15. Fermi trigger No 740221779: Global MASTER-Net observations report
  16. Fermi GRB 240616A: Global MASTER-Net observations report
  17. GRB 240615A: GOTO optical upper limits
  18. Fermi trigger No 740166710: Global MASTER-Net observations report
  19. GRB 240615A: Swift ToO observations
  20. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  21. Fermi GRB 240612B: Global MASTER-Net observations report
  22. Fermi GRB 240612A: Global MASTER-Net observations report
  23. Fermi GRB 240611A: Global MASTER-Net observations report
  24. GRB 240529A: LBT optical detection and late temporal decay
  25. Trigger 1236151: Swift detection of EXO 0748-676
  26. Fermi GRB 240610A: Global MASTER-Net observations report
  27. Fermi trigger No 739632045: Global MASTER-Net observations report
  28. Fermi GRB 240608A: Global MASTER-Net observations report
  29. Fermi trigger No 739506569: Global MASTER-Net observations report
  30. Fermi GRB 240607A: Global MASTER-Net observations report
  31. GRB 240529A: NOEMA detection
  32. GRB 240529A: radio detection with AMI-LA
  33. Fermi trigger No 739373591: Global MASTER-Net observations report
  34. GRB 240606B: Swift-XRT afterglow detection
  35. Swift GRB240606.15: Global MASTER-Net observations report
  36. GRB 240606B: Swift ToO observations
  37. GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
  38. Fermi GRB 240604A: Global MASTER-Net observations report
  39. Fermi GRB 240605A: Global MASTER-Net observations report
  40. Fermi GRB 240605C: Global MASTER-Net observations report
  41. GRB 240529A: SAO RAS optical observations
  42. Fermi GRB 240603C: Global MASTER-Net observations report
  43. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  44. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  45. GRB 240529A: MASTER prompt OT detection
  46. GRB 240529A: continued SAO RAS optical observations
  47. Fermi GRB 240602A: Global MASTER-Net observations report
  48. GRB 240529A: OSN optical detection
  49. GRB 240529A: further SAO RAS optical observations
  50. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  51. LXT 240528A: GSP optical upper limit
  52. GRB 240529A: 1.3m DFOT Optical observations
  53. GRB 240529A : Mondy optical observations
  54. GRB 240529A: SAO RAS optical observations
  55. GRB 240529A: optical photometry from Konkoly
  56. GRB 240529A: T193/MISTRAL observations
  57. GRB 240529A: AKO Optical Afterglow Detection
  58. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  59. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  60. GRB 240529A: J-band detections with WINTER
  61. GRB 240529A: Skynet Optical Observations
  62. LXT 240528A: LEIA detection of a fast X-ray transient
  63. LIGO/Virgo S240527fv: GRANDMA/FRAM-Auger Optical Observations
  64. GRB 240529A: Swift/UVOT Detection
  65. GRB 240529A: NOT optical observations
  66. GRB 240529A: GOTO optical afterglow detection
  67. GRB 240527B: Swift-XRT afterglow detection
  68. Swift GRB240529.12: Global MASTER-Net observations report
  69. Fermi GRB 240527A: Global MASTER-Net observations report
  70. LAT GRB240527.59: Global MASTER-Net observations report
  71. Fermi GRB 240527B: Global MASTER-Net observations report
  72. Fermi trigger No 738348224: Global MASTER-Net observations report
  73. Fermi trigger No 738330463: Global MASTER-Net observations report
  74. Fermi GBM Sub-Threshold Detection of GRB 240516B
  75. GRB 240513A: Swift-XRT afterglow detection
  76. GRB 240521B: Swift/BAT-GUANO arcminute localization of a long burst
  77. Fermi trigger No 737996942: Global MASTER-Net observations report
  78. EP240518a: GSP optical upper limit
  79. LIGO/Virgo/KAGRA S240515m: Upper limits from Swift/BAT-GUANO
  80. LIGO/Virgo/KAGRA S240514x: Upper limits from Swift/BAT-GUANO
  81. LIGO/Virgo/KAGRA S240513ei: Upper limits from Swift/BAT-GUANO
  82. GRB 240516A: Swift/UVOT Upper Limits
  83. Fermi trigger No 737788024: Global MASTER-Net observations report
  84. EP240518a: EP-WXT detection of a new X-ray transient
  85. Fermi GRB 240517A: Global MASTER-Net observations report
  86. GRB 240516A ATCA radio observations
  87. GRB 240513A: Swift ToO observations
  88. GRB 240514E: A possible candidate BD-21 1074
  89. Fermi trigger No 737559855: Global MASTER-Net observations report
  90. GRB 240511A: Observations from GTC/OSIRIS+
  91. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  92. GRB 240516A: GOTO optical upper limit
  93. Fermi trigger No 737523389: Global MASTER-Net observations report
  94. Swift GRB240516.15: Global MASTER-Net observations report
  95. Fermi trigger No 737476171: Global MASTER-Net observations report
  96. GRB 240511A: radio detection of afterglow candidate
  97. GRB 240514B: GOTO candidate optical counterpart
  98. MAXI GRB240514.78: Global MASTER-Net observations report
  99. LIGO/Virgo/KAGRA S240422ed: Las Cumbres Observatory Follow-up Observations of the Localization Region
  100. GRB 240513A: Swift-XRT 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