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 150211A iTelescope observation
  2. GRB 150211A: Swift/UVOT Upper Limits
  3. GRB 150210A: MASTER SN detection during LAT error box inspection
  4. GRB 150211A: Swift-BAT refined analysis
  5. GRB 150211A: KAIT Optical Upper Limit
  6. GRB 150211A: Mondy optical upper limit
  7. GRB 150211A: Swift-XRT refined Analysis
  8. GRB 150210A: Tiled Swift observations
  9. Konus-Wind observation of GRB 150210A
  10. IPN Triangulation of GRB 150210A
  11. GRB 150210A: Fermi-LAT detection
  12. GRB 150211A: RATIR Optical and NIR Observations
  13. GRB 150211A: No afterglow detection in the Swift/UVOT initial observation
  14. GRB 150211A: Swift-XRT observations
  15. GRB 150211A: Swift detection of a burst
  16. GRB 150211A: MASTER early optical observations
  17. GRB 150210A: Fermi GBM detection
  18. GRB 150101B/ Swift J123205.1-105602: Second epoch Chandra observations
  19. GRB 150204A: GROND observations
  20. GRB 150202B: Swift/XRT afterglow confirmation
  21. GRB 150204A: Swift/XRT afterglow confirmation
  22. Konus-Wind observation of GRB 150206A
  23. GRB 150206A: Swift-BAT refined analysis
  24. GRB 150203A iTelescope observation
  25. GRB 150206A: Swift/UVOT Detection
  26. GRB 150206A: Swift-XRT refined Analysis
  27. Konus-Wind observation of GRB 150202B
  28. GRB 140206B: Continued iPTF Observations
  29. GRB 150206A: VLT/X-shooter redshift
  30. GRB 150206A: GROND afterglow observations
  31. GRB 150206A: Enhanced Swift-XRT position
  32. GRB 150206B: Fermi GBM detection
  33. Trigger 630047: Swift detection of 1RXS J180408.9-342058
  34. GRB 150206B: iPTF Optical Observations
  35. GRB 150206A: MAXI/GSC detection
  36. GRB 150206A: Swift detection of a burst with an optical afterglow
  37. GRB 150204A: LCOGT-Sutherland and Siding Springs observations
  38. GRB 150204A: Swift/UVOT Upper Limits
  39. GRB 150203A: Swift-BAT refined analysis
  40. GRB 150204A: Swift-XRT observations
  41. GRB 150204A: Fermi GBM detection
  42. GRB 150204A: Swift ToO observations
  43. GRB 150204A BAT refined analysis
  44. GRB 150202B: Swift XRT/UVOT observations
  45. GRB 150204A found in ground analysis of Swift-BAT data
  46. Swift Trigger 629693 was a noise event
  47. GRB 150203A: RAPTOR Limits Beginning at the Gamma-Ray Emitting Interval
  48. GRB 150202A, Swift-BAT refined analysis
  49. GRB 150203A: Swift/UVOT Upper Limits
  50. GRB 150203A: ISON-NM early optical limit
  51. IPN Triangulation of GRB 150202B
  52. GRB 150203A: Swift-XRT refined Analysis
  53. GRB 150202B: Tiled Swift observations
  54. GRB 150203A: MITSuME Okayama upper limits
  55. Swift Trigger 629693: probably not real
  56. Fermi GBM trigger 150202624 is not a GRB
  57. GRB 150202A: Swift/UVOT Upper Limits
  58. GRB 150203A: REM optical and NIR observations
  59. GRB 150202A: Swift-XRT refined Analysis
  60. GRB 150203A: Fermi GBM observation
  61. GRB 150202B: Fermi GBM detection
  62. GRB 150203A: TAROT La Silla observatory optical observations
  63. GRB 150203A: GROND Upper limits
  64. GRB 150202B: Fermi-LAT detection
  65. GRB 150203A: Enhanced Swift-XRT position
  66. GRB 150203A: RATIR Optical and NIR Observations
  67. GRB 150202A: Enhanced Swift-XRT position
  68. GRB 150202A: GROND Upper limits
  69. GRB 150203A: P60 observations
  70. GRB 150203A: KAIT Optical Upper Limit
  71. GRB 150203A: Prompt enhanced Swift-XRT position
  72. GRB 150203A: Swift detection of a burst
  73. GRB 150202A: Swift detection of a burst
  74. GRB 150201A: Swift/UVOT Upper Limits
  75. GRB 150201A, Swift-BAT refined analysis
  76. Konus-Wind observation of GRB 150201A
  77. GRB 150201A: GROND upper limits
  78. GRB 150201A: Swift-XRT refined Analysis
  79. GRB 150201A: Fermi GBM observation
  80. GRB 150201A: Enhanced Swift-XRT position
  81. GRB 150201A: Swift detection of a burst
  82. Swift Trigger 629206 is likely 1RXS J180408.9-342058
  83. GRB 150120B: Khureltogot optical observations
  84. GRB 150128A: MASTER OT detction during inspection
  85. GRB 150127B: Fermi GBM detection
  86. Konus-Wind observation of GRB 150127B
  87. GRB 150123A: MASTER inspection
  88. GRB 150120A: 9.8 GHz VLA upper limit
  89. IPN Triangulation of GRB 150127B
  90. IPN Triangulation of GRB 150127A
  91. GRB 150120A: Gemini-N imaging and host redshift
  92. Konus-Wind observation of GRB 150126A reveals its ultra-long nature
  93. GRB 150127A: Fermi-LAT detection
  94. GRB150127A: Fermi GBM Detection
  95. Swift Trigger 628458 likely not astrophysical
  96. GRB 150126A: Fermi GBM Detection
  97. GRB 150126A: MAXI/GSC afterglow candidate detection
  98. Konus-Wind observation of GRB 150123A
  99. GRB 150120A: possible AMI 15 GHz detection
  100. GRB 150123A: Swift/UVOT observations

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