Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

"200205A/SWIFT J0840.7-3516" does not adhere to advanced search syntax. Please refer to the documentation and try again.
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"

19596 results found.

  1. GRB 210807A: Swift-BAT refined analysis
  2. GRB 210802A: Further Swift/XRT observation and afterglow confirmation
  3. GRB 210807C: Swift-XRT refined Analysis
  4. GRB 210807C: Fermi GBM detection
  5. GRB 210807C: Swift/UVOT Upper Limits
  6. GRB 210807A: Swift/UVOT Detection
  7. GRB 210807A: Swift-XRT refined Analysis
  8. GRB 210807C: Enhanced Swift-XRT position
  9. Swift GRB210807.74: Global MASTER-Net observations report
  10. Swift GRB210807.96: Global MASTER-Net observations report
  11. GRB 210807C: Swift detection of a burst
  12. Swift GRB 210807A: Global MASTER-Net observations report
  13. Swift GRB210807.79: Global MASTER-Net observations report
  14. Swift GRB210807.78: Global MASTER-Net observations report
  15. GRB 210807A: Enhanced Swift-XRT position
  16. GRB 210807A: BOOTES-5/JGT optical afterglow detection
  17. GRB 210807A: Swift detection of a burst with an optical counterpart
  18. IPN Triangulation of a bright burst from SGR 1935+2154
  19. GRB 210802A: BOOTES-2/TELMA optical upper limit
  20. GRB 210802A: Swift-XRT afterglow detection
  21. GRB 210802A: Fermi-LAT detection
  22. GRB 210802A: Tiled Swift observations
  23. GRB 210731A: continued GROND observations
  24. GRB 210731A: KAIT Optical Detection
  25. GRB 210731A: Swift-BAT refined analysis
  26. GRB 210731A: MASTER optical afterglow detection
  27. GRB 210731A: Swift-XRT refined Analysis
  28. GRB 210731A: GROND observations
  29. GRB 210731A: Fermi GBM Observation
  30. GRB 210731A: Swift/UVOT Detection of an optical afterglow
  31. Swift GRB210731.62: Global MASTER-Net observations report
  32. GRB 210731A: MeerLICHT optical afterglow detection
  33. GRB210731A: Enhanced Swift-XRT position
  34. GRB 210731A: Swift detection of a burst
  35. Swift GRB210731.93: Global MASTER-Net observations report
  36. Trigger 1062273: Swift detection of 4U 1700-377
  37. GRB 210730A: BOOTES-5/JGT and 2.2m CAHA telescopes optical limit
  38. Swift GRB 210730A: Global MASTER-Net observations report
  39. GRB 210726A: Chandra detection of the X-ray afterglow
  40. GRB 210730A: Fermi GBM observation
  41. GRB 210730A: AstroSat CZTI detection
  42. GRB 210730A: Swift-BAT refined analysis
  43. GRB 210730A: Swift-XRT refined Analysis
  44. GRB 210730A: Swift/UVOT Upper Limits
  45. GRB 210730A: Enhanced Swift-XRT position
  46. GRB 210730A: Swift detection of a burst near M82
  47. GRB 210724A: Corrected Swift-XRT enhanced position
  48. Fermi GBM Sub-Threshold Detection of GRB 210725B
  49. IPN triangulation of GRB 210727A (short)
  50. Fermi GBM Sub-Threshold Detection of GRB 210726A
  51. GRB 210726A: Swift-XRT refined Analysis
  52. GRB 210726A: Swift-BAT refined analysis
  53. GRB 210726A: Likely a short burst
  54. GRB 210726A: RATIR Optical Upper Limits and Candidate Host Galaxy
  55. GRB 210724A: Swift/UVOT Upper Limits
  56. GRB 210723A: Swift/UVOT Upper Limits
  57. GRB 210725A: Swift/UVOT Upper Limits
  58. GRB 210725B: Swift/UVOT Upper Limits
  59. GRB 210726A: CAHA 2.2m telescope optical limit
  60. GRB 210726A: Enhanced Swift-XRT position
  61. GRB 210726A: Swift detection of a burst
  62. Swift GRB210726.80: Global MASTER-Net observations report
  63. GRB 210725B: Swift-XRT refined Analysis
  64. GRB 210725A: Fermi GBM detection
  65. GRB 210725A: Swift-XRT refined Analysis
  66. GRB 210725B: Swift-BAT refined analysis
  67. GRB 210724A: Swift-XRT refined Analysis
  68. GRB 210725A: Swift-BAT refined analysis
  69. GRB 210724A: Swift-BAT refined analysis
  70. Swift GRB 210725B: Global MASTER-Net observations report
  71. GRB 210725B: Enhanced Swift-XRT position
  72. GRB 210725A: MITSuME Akeno optical upper limits
  73. GRB 210725B: Swift detection of a burst
  74. GRB 210725A: CALET Gamma-Ray Burst Monitor detection
  75. GRB 210723A: CALET Gamma-Ray Burst Monitor detection
  76. GRB 210725A: KAIT Optical Upper Limit
  77. GRB 210725A: Swift detection of a burst
  78. Swift GRB210725.16: Global MASTER-Net observations report
  79. GRB 210723A: Fermi GBM Observation
  80. GRB210724A: MeerLICHT upper limits
  81. GRB 210724A: Swift detection of a burst
  82. Swift GRB210724.84: Global MASTER-Net observations report
  83. GRB 210723A: Swift-BAT refined analysis
  84. GRB 210723A: Swift-XRT refined Analysis
  85. Swift GRB 210723A: Global MASTER-Net observations report
  86. GRB 210722A: Fermi GBM observation
  87. GRB 210722A: Swift-BAT refined analysis
  88. GRB 210723A: Prompt enhanced Swift-XRT position
  89. GRB 210723A: Swift detection of a burst
  90. GRB 210722A: Swift-XRT refined Analysis
  91. GRB 210722A: Swift/UVOT Detection
  92. GRB 210722A: GIT optical detection and preliminary analysis
  93. Swift GRB 210722A: Global MASTER-Net observations report
  94. GRB 210722A: Nanshan/NEXT optical afterglow observations
  95. GRB 210722A: Swift detection of a burst with a bright optical counterpart
  96. GRB 210712A: Swift-BAT refined analysis
  97. GRB 210712A: Swift-XRT refined Analysis
  98. GRB 210712A: Swift/UVOT Upper Limits
  99. GRB 210712A: BOOTES-3/YA optical upper limit
  100. GRB 210712A: Enhanced Swift-XRT position

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