Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
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"
  1. GRB 180314A: Enhanced Swift-XRT position
  2. GRB180314A: GROND detection of the afterglow
  3. GRB 180314A: Swift detection of a burst with an optical counterpart
  4. Trigger 814090: Swift detection of MAXI J1820+070
  5. GRB 180305A: AstroSat CZTI detection
  6. GRB 180311A: Swift/UVOT Upper Limits
  7. GRB 180311A, Swift-BAT refined analysis
  8. GRB 180311A: Swift-XRT refined Analysis
  9. MAXI J1820+070: Swift/UVOT counterpart correction
  10. Swift detection of MAXI J1820+070
  11. GRB 180311A: Enhanced Swift-XRT position
  12. GRB 180311A: Prompt enhanced Swift-XRT position
  13. GRB 180311A: Swift detection of a burst
  14. GRB 180305A CALET Gamma-Ray Burst Monitor detection
  15. Trigger 813449: Swift detection of large burst from XTE J1701-407
  16. GRB 180305A: RATIR Optical Observations
  17. GRB 180305A: Swift/UVOT Upper Limits
  18. GRB 180305A: Mondy optical observations
  19. GRB 180305A: Swift-XRT afterglow detection
  20. Konus-Wind observation of GRB 180305A
  21. GRB 180305A: RATIR Optical Afterglow Candidate
  22. GRB 180305A: Swift ToO observations
  23. GRB 180305A: Fermi GBM detection
  24. GRB 180305A: Fermi-LAT detection
  25. GRB 180221B: Insight-HXMT/HE observation
  26. Fermi GBM trigger 541402602/180227234 is not a GRB
  27. GRB 180224A: Swift/UVOT Detection
  28. Konus-Wind observation of GRB 180223A
  29. GRB 180224A: OASDG optical observations
  30. IPN Triangulation of GRB 180223A (long)
  31. GRB 180210A: Insight-HXMT/HE observation
  32. Swift Trigger 811686 is probably not an astrophysical source.
  33. GRB 180224A: AbAO optical observations
  34. GRB 180224A: Swift-BAT refined analysis
  35. GRB 180224A: RATIR Optical Observations
  36. GRB 180224A: Swift-XRT refined Analysis
  37. GRB180224A: Global MASTER-Net bright OT detection
  38. GRB 180224A: Enhanced Swift-XRT position
  39. GRB 180224A: Swift detection of a burst with an optical counterpart
  40. GRB 180218A: AstroSat CZTI detection
  41. MAXI J1813-095 source: AbAO optical observations
  42. GRB 180222A: Swift/UVOT Upper Limits
  43. GRB 180221B CALET Gamma-Ray Burst Monitor detection
  44. GRB 180222A: Swift-XRT refined Analysis
  45. GRB 180222A: Swift-BAT refined analysis
  46. GRB 180222A: Enhanced Swift-XRT position
  47. GRB 180222A: A long GRB detected by INTEGRAL
  48. GRB 180222A: Swift detection of a burst
  49. Swift trigger 811074 (possible GRB 180221A): Swift refined analysis
  50. Swift Trigger 811167: Detection of MAXI J1813-095
  51. GRB 180205A: Mondy optical observations
  52. GRB 180219A CALET Gamma-Ray Burst Monitor detection
  53. GRB180221A: MASTER-OAFA optical observations
  54. Swift Trigger 811074: possible GRB 180221A
  55. Konus-Wind observation of GRB 180218A
  56. GRB 180218A CALET Gamma-Ray Burst Monitor detection
  57. GRB 180218A: Fermi GBM Detection
  58. IPN Triangulation of GRB 180218A (long/bright)
  59. GRB 180204A: 15 GHz upper limits from AMI
  60. GRB 180112A: AstroSat CZTI detection
  61. Fermi GBM triggers 540405116/180215689 and 540476225/180216512 are not a GRBs
  62. Swift J1658.2-4242: Swift BAT and XRT refined analysis
  63. Swift trigger 810300: MASTER-OAFA robotic report
  64. Swift J1658.2-4242 (trigger 810300): Swift-XRT position
  65. Swift Trigger 810300 is a probable new Galactic source: Swift J1658.2-4242
  66. Konus-Wind observation of GRB 180210A
  67. GRB 180205A: SEDM Observations
  68. GRB 180210A: Swift-XRT afterglow detection
  69. GRB 180210A: Tiled Swift observations
  70. GRB 180205A: BAO optical observations
  71. Retraction of Swift trigger 809374
  72. GRB 180210A: Swift ToO observations
  73. GRB 180210A: Fermi-LAT detection
  74. GRB 180210A: Fermi GBM detection
  75. Trigger 809374: Swift detection of a possible non-burst faint source
  76. Trigger 809217: Swift trigger on RS CVn Star HD 8357
  77. GRB180205A: Optical observations with DOAO 1m telescope
  78. GRB 180205A: AbAO optical observations
  79. Fermi-GBM Detection of possible burst from AXP CXOU J164710.2-455216/PSR J1647-4552
  80. GRB 180205A optical observations
  81. GRB 180202A: Insight-HXMT/HE detection
  82. GRB 180204A: MITSuME Okayama optical upper limits
  83. GRB 180205A: confirmation of Swift-BAT trigger time.
  84. GRB 180205A: Optical observations
  85. GRB 180205A: Swift/UVOT Detection
  86. GRB 180205A: Nanshan-1m optical observations
  87. GRB 180205A: Swift-XRT refined Analysis
  88. GRB 180205A: Swift-BAT refined analysis
  89. GRB 180205A: Xinglong TNT optical observation
  90. GRB 180205A: Further GROND Observations reveal Afterglow is still bright
  91. GRB 180205A: Nickel telescope optical observations
  92. Swift Trigger on AXP CXOU J164710.2-455216/PSR J1647-4552
  93. GRB 180205A: VLT polarimetry
  94. GRB 180205A: Mondy optical observations
  95. GRB 180205A: Fermi GBM observation
  96. Konus-Wind observation of GRB 180204A
  97. GRB 180205A: VLT/X-shooter redshift
  98. GRB 180205A: GROND detection of the NIR/optical afterglow
  99. GRB 180205A: KAIT optical afterglow confirmation
  100. GRB 180205A: Swift detection of a burst with a bright optical counterpart

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