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.

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"

26040 results found.

  1. GRB 220708B: Swift ToO observations
  2. GRB 220708B: Swift/BAT-GUANO arcminute localization
  3. GRB 220708A: Swift-XRT observations
  4. GRB 220708A: Swift detection of a burst
  5. GRB 220706A: LCO Optical Upper Limits
  6. GRB 220627A: ATCA detection of radio counterpart
  7. GRB 220706A: Swift-XRT refined Analysis
  8. GRB 220706A, GROND observations
  9. GRB 220706A: Optical observations from NOT
  10. GRB 220706A: MAXI/GSC detection 84 minutes after the Swift Trigger
  11. GRB 220706A: Nanshan/NEXT optical upper limits
  12. GRB 220706A: Enhanced Swift-XRT position
  13. Swift GRB 220706A: Global MASTER-Net observations report
  14. GRB 220706A: Zadko observatory - Gingin optical observations
  15. GRB 220706A: Prompt enhanced Swift-XRT position
  16. GRB 220706A: Swift detection of a burst
  17. GRB 220701A: Swift-BAT refined analysis
  18. GRB220408A: VIRT Optical Upper Limit
  19. GRB220412A: VIRT Optical Upper Limit
  20. GRB220701A: VIRT Optical Upper Limit
  21. GRB 220701A: MITSuME Akeno optical upper limits
  22. GRB 220701A: COATLI Optical Upper Limit
  23. GRB 220701A: AbAO optical upper limit
  24. GRB 220627A: AstroSat CZTI detection
  25. GRB 220701A: Keck/LRIS Optical Upper Limit
  26. GRB 220701A: Swift-XRT refined Analysis
  27. GRB 220701A: LCO Optical Upper Limits
  28. GRB 220701A: BOOTES-5/JGT early optical upper limit
  29. GRB 220701A: Swift/UVOT Upper Limits
  30. GRB 220701A: Lowell Discovery Telescope Optical Observations
  31. GRB 220701A: Enhanced Swift-XRT position
  32. GRB 200701A: KAIT Optical Upper Limit
  33. GRB 220701A: Swift detection of a burst
  34. GRB 220627A: Swift/UVOT Upper Limits
  35. GRB 220627A: Swift-XRT afterglow detection
  36. Konus-Wind detection of GRB 220627A
  37. Trigger 1113743: Swift detection of MAXI J0655-013
  38. IceCube-220624A: One Candidate Counterpart from Swift/XRT follow up observations
  39. GRB 220627A: VLT MUSE redshift
  40. Swift XRT observations of WISEA J145820.77+412101.9 / IceCube 220624A
  41. GRB 220627A: MeerLICHT candidate optical afterglow
  42. GRB 220627A: Fermi GBM Detection of a possible Lensed or Ultra-long GRB
  43. GRB 220627A: Swift/BAT-GUANO detection outside the coded FOV
  44. Konus-Wind detection of GRB 220624A
  45. GRB 220627A: Swift ToO observations
  46. GRB 220627A: Fermi-LAT detection
  47. GRB 220627A: MeerLICHT detection of two afterglow candidates
  48. GRB 220623A: GIT optical upper limits.
  49. GRB 220624A: CALET Gamma-Ray Burst Monitor detection
  50. GRB 220623A: T193-OHP optical upper limit
  51. GRB 220624A: Fermi GBM Detection
  52. IPN triangulation of GRB 220624A
  53. GRB 220623A: Swift-BAT refined analysis
  54. GRB 220624A: Swift/BAT-GUANO detection outside the coded FOV
  55. GRB 220611A: X-ray afterglow Chandra sub-arcsecond localization
  56. Konus-Wind detection of GRB 220623A
  57. GRB 220623A: AbAO optical upper limit
  58. GRB 220623A: Swift-XRT refined Analysis
  59. GRB 220623A: NOT optical observations
  60. GRB 220623A: Swift/UVOT Upper Limits
  61. GRB 220623A: BOOTES-5/JGT optical afterglow detection
  62. GRB 220623A: Enhanced Swift-XRT position
  63. GRB 220623A: AGILE detection
  64. GRB 220623A: AstroSat CZTI detection
  65. GRB 220623A: iTelescope optical upper limit
  66. GRB 220623A: Swift-XRT observations
  67. GRB 220623A: Swift detection of a burst
  68. GRB 220618A: Fermi GBM detection
  69. Swift Detection of MAXI J0655-013
  70. GRB 220618A: Swift-BAT refined analysis
  71. GRB 220618A: iTelescope T-19 upper limit
  72. Swift GRB220620.02: Global MASTER-Net observations report
  73. GRB 220611A: Continued Gemini Infrared Observations
  74. GRB 220617A: TNG optical observations
  75. Swift Trigger 1110865 is probably not an astrophysical event
  76. GRB 220618A: Swift-XRT refined Analysis
  77. IPN triangulation of GRB 220617A (short)
  78. GRB 220618A: BOOTES-5/JGT early optical upper limit
  79. GRB 220618A: Swift/UVOT Upper Limits
  80. GRB220611A: Gemini Optical Afterglow Confirmation
  81. GRB 220618A: Enhanced Swift-XRT position
  82. GRB 220617A: Swift-XRT observations
  83. GRB 220618A: Swift detection of a burst
  84. Swift GRB220618.38: Global MASTER-Net observations report
  85. GRB 220617A: Fermi-LAT detection
  86. GRB 220617B: Swift ToO observations
  87. GRB 220611A: Gemini South Infrared Detection
  88. GRB 220611A: Swift/UVOT Upper Limits
  89. GRB 220612A: CALET Gamma-Ray Burst Monitor detection
  90. GRB 220612A: Swift/BAT-GUANO detection
  91. GRB 220611A: Swift-BAT refined analysis
  92. Swift GRB 220611A: Global MASTER-Net observations report
  93. GRB 220611A: Swift-XRT refined Analysis
  94. GRB 220611A: Enhanced Swift-XRT position
  95. GRB 220611A: Swift detection of a burst
  96. GRB 220606A: Fermi GBM observation
  97. GRB 220606B: Gemini South Optical Observations
  98. GRB 220606B: Fermi GBM Observation
  99. GRB 220606B: Swift follow-up observations
  100. GRB 220606A: Swift/BAT-GUANO detection

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