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"

19607 results found.

  1. GRB 240513A: Swift ToO observations
  2. GRB 240516A: AstroSat CZTI detection
  3. GRB 240516A: Swift-XRT refined Analysis
  4. GRB 240514E: A possible candidate BD-21 1074
  5. GRB 240516A: Fermi GBM Observation
  6. GRB 240516A: GOTO optical upper limit
  7. GRB 240516A: Swift detection of a burst
  8. Swift GRB240516.15: Global MASTER-Net observations report
  9. GRB 240513A: Swift-XRT observations
  10. LIGO/Virgo/KAGRA S240507p: Upper limits from Swift/BAT-GUANO
  11. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  12. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  13. GRB 240513A: Tiled Swift observations
  14. GRB 240513A: Fermi-LAT detection
  15. GRB 240511A: Fermi GBM Observation
  16. GRB 240511A: Swift-BAT refined analysis
  17. GRB 240511A: J-band observations with WINTER
  18. GRB 240511A: Enhanced Swift-XRT position
  19. GRB 240511A : MITSuME Akeno optical upper limits
  20. GRB 240511A: Swift-XRT refined Analysis
  21. Swift GRB 240511A: Global MASTER-Net observations report
  22. GRB 240511A: Prompt enhanced Swift-XRT position
  23. GRB 240511A: Swift detection of a burst
  24. GRB 240504A: Fermi GBM Observation
  25. IPN triangulation of GRB 240504A
  26. GRB 240504A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  27. GRB 240415A 1.3m DFOT Optical upper limit
  28. LIGO/Virgo S240422ed: Swift XRT observation of EP240426a
  29. LVK S240422ed: Further Swift-XRT followup of three sources
  30. LIGO/Virgo/KAGRA S240422ed: Magellan Follow-up Observations of Swift/XRT candidates
  31. LIGO/Virgo/KAGRA S240422ed: 2.5m PRL Telescope follow-up of the Swift/XRT source S240422ed_X190
  32. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-FXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
  33. LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limits for Swift/XRT candidates
  34. GRB 240419B: Swift-BAT refined analysis
  35. GRB 240421B: Swift-BAT refined analysis
  36. LIGO/Virgo/KAGRA S240422ed: Himalayan Chandra Telescope follow-up of the Swift/XRT source S240422ed_X101
  37. IceCube-240424A - IceCube observation of a high-energy neutrino candidate track-like event
  38. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
  39. LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
  40. LIGO/Virgo/KAGRA S240422ed: NOT J-band upper limit on the Swift/XRT source S240422ed_X61
  41. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Three Potential Electromagnetic Counterparts Reported So Far
  42. GRB 240421B: GRBAlpha detection
  43. LIGO/Virgo/KAGRA S240422ed: WINTER J-band upper limits on the Swift/XRT source S240422ed_X61
  44. LIGO/Virgo/KAGRA S240422ed: GW-MMADS DECam upper limits on the Swift/XRT source S240422ed_X61
  45. GRB 240419A: Swift-BAT refined analysis
  46. GRB 240418A: Swift-BAT refined analysis
  47. LXT240402A/GRB240402B: Chandra X-ray detection
  48. LIGO/Virgo/KAGRA S240421ar: Upper limits from Swift/BAT-GUANO
  49. GRB 240419B : MITSuME Akeno optical upper limits
  50. GRB 240415B: Swift-XRT observations
  51. GRB 240415A: Swift-XRT refined Analysis
  52. GRB 240421B: AstroSat CZTI detection
  53. GRB240421B: Zadko Observations
  54. Swift GRB 240421B: Global MASTER-Net observations report
  55. GRB 240421B: Fermi GBM Observation
  56. GRB 240421B: Swift-XRT refined Analysis
  57. GRB240421B: BOOTES-5/JGT optical upper limit
  58. GRB 240421B: Swift/UVOT Upper Limits
  59. GRB 240421B: Enhanced Swift-XRT position
  60. GRB 240421B: Swift detection of a burst
  61. GRB240419A: Skynet Optical Afterglow Analysis
  62. GRB 240419B: Swift/UVOT Upper Limits
  63. GRB 240419A: Swift/UVOT Upper Limits
  64. GRB 240419B: Swift-XRT refined Analysis
  65. Swift GRB 240419B: Global MASTER-Net observations report
  66. GRB 240419B: Enhanced Swift-XRT position
  67. Swift GRB 240419A: Global MASTER-Net observations report
  68. GRB 240418A: Swift/UVOT Upper Limits
  69. GRB 240419A: Swift-XRT refined Analysis
  70. GRB 240418A: Swift-XRT refined Analysis
  71. GRB 240419B: Swift detection of a burst
  72. GRB 240411B: Swift/UVOT Detection
  73. GRB240418A: YAHPT Upper Limits
  74. GRB 240419A: Enhanced Swift-XRT position
  75. GRB 240419A: Prompt enhanced Swift-XRT position
  76. GRB 240419A: Swift detection of a burst
  77. GRB 240418A: TSHAO Zeiss-1000 optical upper limit
  78. GRB 240418A: Enhanced Swift-XRT position
  79. Swift GRB240418.85: Global MASTER-Net observations report
  80. GRB 240418A: Swift detection of a burst
  81. Improved IPN triangulation of GRB 240411A
  82. GRB 240415A: Glowbug gamma-ray detection
  83. GRB 240414A: Glowbug gamma-ray detection
  84. GRB 240415B: GECAM-B detection
  85. GRB 240415A: Swift-BAT refined analysis
  86. GRB 240411A: Glowbug gamma-ray detection
  87. GRB 240414A: Swift-BAT refined analysis
  88. GRB 240414A: AbAO optical upprer limit
  89. GRB 240415A: Swift/UVOT Detection
  90. GRB 240415A: Fermi GBM Observation
  91. GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
  92. GRB 240415A: Enhanced Swift-XRT position
  93. GRB 240415B: Swift ToO observations
  94. GRB 240415B: Swift/BAT-GUANO Correction
  95. GRB 240415B: Swift/BAT-GUANO arcminute localization of a short burst
  96. GRB 240414A: Fermi GBM Observation
  97. GRB 240414A: Swift/UVOT Detection
  98. LXT 240402A/GRB 240402B: Swift follow-up observations
  99. GRB 240414A: Mondy optical observations
  100. GRB 240415A: Prompt Swift-XRT observations

Advanced

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