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"
  1. GRB 151127A: LCOGT-SSO optical upper limits
  2. GRB 151127A: Swift detection of a short burst
  3. GRB 151118A iTelescope observation
  4. GRB 151122A: Swift/UVOT Observations
  5. GRB 151122A: Swift-XRT observations
  6. GRB 151122A: Fermi GBM detection
  7. GRB 151122A: Swift ToO observations
  8. GRB 151122A: Swift detection of a burst
  9. Konus-Wind observation of GRB 151120A
  10. GRB 151027A: Maidanak optical observations
  11. Swift-BAT refined analysis of trigger 664624 from SGR J1819-1600
  12. Swift Trigger 664610 is not astrophysical
  13. Swift-BAT probable detection of an outburst from SGR J1819-1600 (AX J1818.8-1559)
  14. Swift Trigger 664610: is unlikely a GRB
  15. GRB 151118A: MITSuME Akeno optical upper limits
  16. GRB 151120A: Swift-XRT afterglow detection
  17. GRB 151120A: Fermi GBM observation
  18. GRB 151118A: AAO optical upper limit
  19. LIGO/Virgo G194575: Updated significance from offline GW analysis
  20. GRB 151120A: Swift ToO observations
  21. GRB 151120A: GROND optical/NIR afterglow
  22. GRB 151120A: A long GRB detected by INTEGRAL
  23. GRB 151118A, Swift-BAT refined analysis
  24. LIGO/Virgo G194575: Fermi GBM Observations
  25. 610 MHz detection of GRB 151027A with the GMRT
  26. GRB 151118A: Early optical limit from pt5m, La Palma
  27. GRB 151118A: ISON-NM early optical limit
  28. GRB 151118A: Swift-XRT refined Analysis
  29. GRB 151027A: SAO RAS and Mt. Terskol observations
  30. GRB 151118A: Swift/UVOT Upper Limits
  31. GRB 151118A: Enhanced Swift-XRT position
  32. GRB GRB 151118A: MASTER-NET optical observations
  33. GRB 151118A: Optical observations from OSN
  34. GRB 151118A: Swift detection of a burst
  35. Swift-BAT resumption of normal operations
  36. GRB151027A; Optical observations
  37. GMRT radio detection of GRB 151027A
  38. GRB 151114A: GROND Detection of the Optical/NIR Afterglow Candidate
  39. GRB 151114A: Swift-XRT refined Analysis
  40. GRB 151107B: CALET Gamma-Ray Burst Monitor detection
  41. GRB 151114A: Swift-BAT refined analysis
  42. GRB 151112A: GROND photometric redshift and i'-band prediction
  43. GRB 151114A: Swift/UVOT Detection
  44. GRB 151114A: LCOGT-FTS afterglow observations
  45. GRB 151114A: Enhanced Swift-XRT position
  46. GRB 151114A: Swift detection of a burst with an optical counterpart
  47. GRB 151111A: GROND confirmation of the afterglow and photometric redshift estimate
  48. GRB 151112A: Swift/UVOT Upper Limits
  49. GRB 151112A: MAXI/GSC detection
  50. GRB 151112A: GROND Detection of the Optical/NIR Afterglow Candidate
  51. GRB 151112A: Swift-XRT refined Analysis
  52. GRB 151112A: Swift-BAT refined analysis
  53. GRB 151112A: Enhanced Swift-XRT position
  54. GRB 151112A: MASTER-NET optical limit
  55. GRB 151112A: initial UVOT observations
  56. GRB 151112A: Swift-XRT observations
  57. GRB 151112A: Swift detection of a burst
  58. GRB 151111A: Swift/UVOT upper limits
  59. Swift-BAT trigger 663164 is not a burst.
  60. GRB 151111A: GROND marginal detection of a afterglow candidate
  61. LIGO/Virgo G194575: VLA follow-up
  62. GRB 151111A: Swift-XRT refined Analysis
  63. GRB 151111A: Fermi GBM observation
  64. GRB 151111A: LCOGT-FTS afterglow observations
  65. GRB 151111A: Swift-BAT refined analysis
  66. GRB 151111A: Enhanced Swift-XRT position
  67. GRB 151111A: Swift detection of a burst
  68. IPN triangulation of GRB151107B
  69. GRB 151107B: MASTER-NET OT detection inside the FERMI error box
  70. GRB 151027A: continued Mondy optical observations
  71. GRB 151107B: Mini-MegaTORTORA limits on simultaneous optical emission
  72. LIGO/Virgo G194575: Liverpool Telescope observations of iPTF-15dld and iPTF-15dni
  73. LIGO/Virgo G194575: La Silla QUEST, Pan-STARRS and PESSTO observations of iPTF15dld
  74. GRB 151107A: Further investigation of the source nature
  75. GRB 151107B
  76. LIGO/Virgo G194575: Swift observations if iPTF15dld
  77. GRB 151107A, Swift-BAT refined analysis
  78. GRB 151027A: Hankasalmi optical observations
  79. LIGO/Virgo G194575: INAF-TNG/Asiago Telescope follow-up of iPTF15dld
  80. GRB 151107A: MASTER-NET optical observations
  81. GRB 151107A: Swift detection of a possible burst
  82. LIGO/Virgo G194575: INAF-Asiago Telescope further analysis of iPTF candidates
  83. Swift-BAT triggers are disabled
  84. LIGO/Virgo G194575: INAF-Asiago Telescope follow-up of iPTF candidates
  85. LIGO/Virgo G194575: VLA follow-up
  86. GRB 151027A: Mondy optical observations
  87. GRB 151027A: Mt. Terskol observatory optical observation
  88. LIGO/Virgo G194575: MAXI/GSC further analysis
  89. GRB 150910A: CrAO optical observations
  90. GRB 151027A: the missing GeV component
  91. GRB 151029A: FRAM optical afterglow detection
  92. LIGO/Virgo G194575: LT Spectroscopy of iPTF-15dmk
  93. GRB 151027A: Correction to GCN 18519
  94. GRB 151031A: MITSuME Akeno optical upper limits
  95. GRB 151031A: GROND observation
  96. LIGO/Virgo G194575: LT Spectroscopy of iPTF candidates
  97. GRB 151027B: ATCA radio detection
  98. GRB 151031A
  99. GRB 151031A: Swift/UVOT Detection
  100. GRB 151030A: 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