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"

21526 results found.

  1. GRB 240415B: Swift-XRT observations
  2. GRB 240415A: Swift-XRT refined Analysis
  3. GRB 240421B: AstroSat CZTI detection
  4. GRB240421B: Zadko Observations
  5. Swift GRB 240421B: Global MASTER-Net observations report
  6. GRB 240421B: Fermi GBM Observation
  7. GRB 240421B: Swift-XRT refined Analysis
  8. GRB240421B: BOOTES-5/JGT optical upper limit
  9. GRB 240421B: Swift/UVOT Upper Limits
  10. GRB 240421B: Enhanced Swift-XRT position
  11. GRB 240421B: Swift detection of a burst
  12. GRB240419A: Skynet Optical Afterglow Analysis
  13. GRB 240419B: Swift/UVOT Upper Limits
  14. GRB 240419A: Swift/UVOT Upper Limits
  15. GRB 240419B: Swift-XRT refined Analysis
  16. Swift GRB 240419B: Global MASTER-Net observations report
  17. GRB 240419B: Enhanced Swift-XRT position
  18. Swift GRB 240419A: Global MASTER-Net observations report
  19. GRB 240418A: Swift/UVOT Upper Limits
  20. GRB 240419A: Swift-XRT refined Analysis
  21. GRB 240418A: Swift-XRT refined Analysis
  22. GRB 240419B: Swift detection of a burst
  23. GRB 240411B: Swift/UVOT Detection
  24. GRB240418A: YAHPT Upper Limits
  25. GRB 240419A: VLT optical afterglow detection
  26. GRB 240419A: Enhanced Swift-XRT position
  27. GRB 240419A: Prompt enhanced Swift-XRT position
  28. GRB 240419A: Swift detection of a burst
  29. GRB 240418A: TSHAO Zeiss-1000 optical upper limit
  30. GRB 240418A: Enhanced Swift-XRT position
  31. GRB 240418A: AKO Upper Limit
  32. Swift GRB240418.85: Global MASTER-Net observations report
  33. GRB 240418A: Swift detection of a burst
  34. Improved IPN triangulation of GRB 240411A
  35. GRB 240415A: Glowbug gamma-ray detection
  36. GRB 240414A: Glowbug gamma-ray detection
  37. GRB 240415B: GECAM-B detection
  38. GRB 240415A: Swift-BAT refined analysis
  39. GRB 240411A: Glowbug gamma-ray detection
  40. GRB 240414A: Swift-BAT refined analysis
  41. GRB 240414A: AbAO optical upprer limit
  42. GRB 240415A: Swift/UVOT Detection
  43. GRB 240415A: Fermi GBM Observation
  44. GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
  45. GRB 240415A: Enhanced Swift-XRT position
  46. GRB 240415B: Swift ToO observations
  47. GRB 240415B: Swift/BAT-GUANO Correction
  48. GRB 240415B: Swift/BAT-GUANO arcminute localization of a short burst
  49. GRB 240414A: Fermi GBM Observation
  50. GRB 240414A: Swift/UVOT Detection
  51. LXT 240402A/GRB 240402B: Swift follow-up observations
  52. GRB 240414A: Mondy optical observations
  53. GRB 240415A: Prompt Swift-XRT observations
  54. GRB 240415A: Swift detection of a burst
  55. GRB 240414A: Swift-XRT refined Analysis
  56. GRB 240414A: Enhanced Swift-XRT position
  57. GRB 240414A: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  58. GRB 240414A: Skynet Optical Afterglow Observations
  59. Swift GRB 240414A: Global MASTER-Net observations report
  60. IPN triangulation of GRB 240410A
  61. IPN triangulation of GRB 240411A
  62. GRB 240414A : MITSuME Akeno optical upper limits
  63. GRB 240414A : OHP/T193 optical counterpart detection
  64. GRB 240414A: Swift detection of a burst
  65. GRB 240411B: Swift-BAT refined analysis
  66. GRB 240411B: Swift-XRT refined Analysis
  67. GRB 240411B: 1.3m DFOT Optical observations
  68. GRB 240411B: Enhanced Swift-XRT position
  69. GRB 240411B: LCO optical afterglow detection
  70. GRB 240411B: Swift detection of a burst
  71. EP240408A: MASTER optical observations
  72. EP240408a: GROND detection of a candidate counterpart
  73. EP240408a: Swift follow-up observation
  74. Swift Trigger 1220736: detection of 4U 1543-62.
  75. Swift satellite resumes pointed science observations
  76. GRB 240318A: Fermi GBM Observation
  77. Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
  78. GRB 240315C / X-ray transient EP240315a: Swift/BAT detection
  79. GRB 240318A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  80. IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a)
  81. GRB 240317B: Swift/BAT-GUANO Angular Error Correction
  82. GRB 240317B: Fermi GBM Observation
  83. Swift satellite in safe mode
  84. GRB 240317B: Swift/BAT-GUANO arcminute localization of a burst
  85. Einstein Probe detected of a fast X-ray transient EP240315a
  86. GRID detection of GRB 240306A
  87. Swift Triggers 1220155, 1220156, 1220157, 1220158, 1220160 and 1220161 were not astrophysical
  88. Swift Triggers 1220093, 1220094, 1220095 and 1220096 are not astrophysical
  89. Swift Triggers 1220090, 1220091 and 1220092 are not astrophysical
  90. GRB240204A: VIRT optical upper limit
  91. Swift triggers 1219917, 1219917 and 1219922 were not astrophysical
  92. Swift Trigger 1219909 and 1219910 are not a astrophysical
  93. Swift Trigger 1219905 is not a GRB
  94. Swift Trigger 1219874 is not astrophysical
  95. Swift GRB240309.61: Global MASTER-Net observations report
  96. Swift Trigger 1219325 is not a GRB
  97. GRB 240306A: Fermi GBM observation
  98. Konus-Wind detection of GRB 231118A
  99. GRB 240306A: AstroSat CZTI detection
  100. GRB 240306A: Swift/BAT-GUANO detection of a burst

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov