Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

6667 results found.

  1. GRB 160117A: Swift-XRT afterglow detection
  2. GRB 160119A: Swift-XRT refined Analysis
  3. GRB 160117B: Early iTelescope observation
  4. GRB 160117A: Swift/UVOT Upper Limits
  5. GRB 160117A: Swift-XRT observations
  6. GRB 160117B: iTelescope T17 optical observations
  7. GRB 160117B: NOT optical afterglow observations
  8. GRB 160117B: Swift-XRT refined Analysis
  9. GRB 160106A: CALET Gamma-Ray Burst Monitor detection
  10. LIGO/Virgo G211117: Further Swift-XRT sources
  11. GRB 160113A: Swift-XRT observations
  12. GRB 160113A: Fermi GBM detection
  13. LIGO/Virgo G211117: Swift observations of PS15dpn
  14. GRB 160107A: Fermi GBM observation
  15. LIGO/Virgo G211117: VISTA imaging
  16. LIGO/Virgo G211117: Further Swift-XRT sources
  17. GRB 160104A: Swift-XRT refined Analysis
  18. GRB 160104A: Fermi GBM observation
  19. GRB 160104A: MITSuME Okayama Ks-band upper-limit
  20. LIGO/Virgo G211117: Fermi/LAT observations
  21. GRB 160102A: Swift-XRT observations
  22. GRB 160101B: Fermi-LAT detection
  23. GRB 160101B: Fermi GBM detection
  24. GRB 160101A: Swift/UVOT Detection
  25. GRB 160101A: Fermi GBM observation
  26. GRB 160101A: Swift-XRT afterglow detection
  27. GRB 151231B: Fermi GBM observation
  28. GRB 151231A: Fermi GBM observation
  29. GRB 151228A: Correction to GCN 18770
  30. LIGO/Virgo G211117: SkyMapper observations and transient candidate
  31. GRB 151228A: Swift-XRT refined Analysis
  32. GRB 151229A Swift-BAT Spectral lag analysis
  33. GRB 151229A: Swift-XRT refined Analysis
  34. GRB 151229A: Fermi GBM observation
  35. GRB 151228B: Fermi GBM observation
  36. GRB 151228B: Swift-XRT refined Analysis
  37. LIGO/Virgo G211117: Further Swift-XRT sources
  38. GRB 151228A: Fermi GBM observation
  39. LIGO/Virgo G211117: Further Swift-XRT sources
  40. LIGO/Virgo G211117: Swift-XRT sources
  41. GRB 151227B: Fermi GBM detection
  42. GRB 151227A: Fermi GBM detection
  43. GRB 151222A: Fermi GBM detection
  44. LIGO/Virgo G184098: Fermi-LAT search for high-energy gamma-ray counterpart
  45. GRB 151215A: TSHAO optical observations
  46. GRB 151210B: Fermi GBM observation
  47. GRB 151215A: Swift-XRT refined Analysis
  48. GRB 151212A: Swift-XRT afterglow detection
  49. GRB 151210A: Swift-XRT refined Analysis
  50. GRB 151205B: further Swift-XRT observations
  51. GRB 151205C: Swift-XRT observations
  52. GRB 151205A: Swift-XRT refined Analysis
  53. GRB 151205A: Fermi GBM detection
  54. LIGO/Virgo G184098: Results of of 2nd epoch of ASKAP follow-up
  55. GRB 151122A: Further Swift-XRT observations, no afterglow detected.
  56. GRB 151127A: Swift-XRT refined Analysis
  57. GRB 151122A: Swift-XRT observations
  58. GRB 151122A: Fermi GBM detection
  59. GRB 151027A: Maidanak optical observations
  60. Swift Trigger 664610 is not astrophysical
  61. GRB 151120A: Swift-XRT afterglow detection
  62. GRB 151120A: Fermi GBM observation
  63. GRB 151118A: Swift-XRT refined Analysis
  64. GRB 151114A: Swift-XRT refined Analysis
  65. GRB 151112A: Swift-XRT refined Analysis
  66. GRB 151111A: Swift-XRT refined Analysis
  67. GRB 151111A: Fermi GBM observation
  68. GRB 151107B
  69. LIGO/Virgo G194575: Swift observations if iPTF15dld
  70. GRB 151030A: Fermi GBM observation
  71. GRB 151031A: Swift-XRT refined Analysis
  72. GRB 151029A: Swift-XRT refined Analysis
  73. GRB 151027A: SAO RAS optical observations
  74. GRB 151027B: Swift-XRT refined Analysis
  75. GRB 151027A: THO optical observations
  76. GRB 151027A: Fermi GBM observation
  77. GRB 151027A: Swift-XRT refined Analysis
  78. LIGO/Virgo G194575: ASKAP followup
  79. GRB 151023A: Swift-XRT refined Analysis
  80. Possible Fermi-LAT Gamma-ray counterpart for LIGO/Virgo G194575
  81. GRB 151022A: Swift-XRT refined Analysis
  82. LIGO/Virgo G194575: Identification of a GW CBC Candidate
  83. GRB 151022A: MITSuME Okayama Ks-band upper-limit
  84. GRB 151022A: Swift detection of a burst
  85. GRB 151021A: MITSuME Okayama Ks-band upper-limit
  86. GRB 151021B: Fermi GBM detection
  87. GRB 151021A: Swift-XRT refined Analysis
  88. GRB 151004A: Swift-XRT follow-up observations
  89. GRB 151006A: MITSuME Okayama Ks-band upper-limit
  90. GRB 151006A: Swift-XRT refined Analysis
  91. GRB 151006A: Fermi-LAT detection
  92. GRB 151006A: Fermi GBM detection
  93. Trigger 657564 / GRB 151004A: Swift BAT and XRT refined analysis
  94. Swift Trigger 657564: XRT prompt analysis
  95. GRB 151001B: Swift-XRT refined Analysis
  96. GRB 151001A: Swift-XRT refined Analysis
  97. GRB 151001A: Fermi GBM detection
  98. GRB 150925A: Swift-XRT refined Analysis
  99. LIGO/Virgo G184098: ASKAP followup
  100. GRB 150922A: Fermi GBM observation

Advanced

Download all Circulars as a .tar.gz archive:
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