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"

42600 results found.

  1. Swift Trigger 536502 is likely a noise fluctuation in coincidence with SAX J1818.6-1703
  2. GRB 121011A: early optical light curve
  3. GRB 121017A: Swift/UVOT Upper Limits
  4. GRB 121017A: Swift-XRT refined Analysis
  5. GRB 121017A: GROND Observations
  6. GRB 121017A: Swift-BAT refined analysis
  7. GRB 121017A: Enhanced Swift-XRT position
  8. GRB 121017A: 1.23m CAHA R-band observations
  9. GRB 121017A optical observations
  10. GRB 121017A: BOOTES-2/TELMA observations
  11. GRB 121017A: Swift detection of a burst
  12. GRB 121011B: Suzaku WAM observation of the prompt emission
  13. GRB 121011A Suzaku WAM observation of the prompt emission
  14. GRB 121012A: Fermi GBM detection
  15. PdB IRAM observation of GRB 121011A
  16. Konus-Wind observation of GRB 121011B
  17. GRB 121014A: Swift-BAT refined analysis
  18. GRB 121011A: WSRT radio observation
  19. GRB 121014A: Swift detection of a burst
  20. INTEGRAL Alert n.6678: NOT A GRB
  21. GRB 121011A: Swift/UVOT Detection
  22. IPN Triangulation of short hard GRB 121011B
  23. GRB 121011A: NOT redshift retraction
  24. GRB 121011A: misprint in GCNC 13854
  25. GRB 121011A: Fermi GBM observation
  26. GRB 121011A: Fermi-LAT detection of a burst
  27. Swift-BAT trigger 535733 is not astrophysical
  28. GRB 121011A: Swift-XRT refined Analysis
  29. GRB 121011A: NOT optical observations
  30. GRB 121011A: optical observations
  31. GRB 121011A: MASTER-Net bell light curve
  32. GRB 121011A: TNG optical observations
  33. GRB 121011A, Swift-BAT refined analysis
  34. Swift-BAT refined analysis of the SGR 1806-20 outburst (trigger 535747)
  35. GRB 121011A: Enhanced Swift-XRT position
  36. Planned XMM-Newton and IRAM observation of GRB 121011A
  37. GRB 121011A: MASTER-Net early OT light curve
  38. GRB121011A : Xinglong TNT optical observation
  39. GRB 121011A: Swift detection of a burst with optical afterglow
  40. Trigger 535747: Swift detection of an outburst from SGR1806-20
  41. Trigger 535733: Swift possible detection of SAX J1828.5-1037
  42. GRB 120927A: optical upper limit
  43. GRB 120804A: Late-time Chandra observation
  44. GRB 121001A: GROND Afterglow Confirmation
  45. GRB 121001A: Swift-XRT refined Analysis
  46. GRB 121001A: Enhanced Swift-XRT Position
  47. Swift Trigger 535026 is GRB 121001A: Swift-BAT refined analysis
  48. Swift Trigger 535026: Optical decay confirmation with IAC80 and BOOTES-2/TELMA.
  49. GRB 121001A: MASTER optical observations
  50. GRB 121001A: possible optical counterpart
  51. Swift Trigger 535026: ROTSE-III Optical Limits
  52. Swift Trigger 535026: Galactic Transient or possible GRB
  53. GRB 120927A: Swift/UVOT Upper Limits
  54. GRB 120927A, Swift-BAT refined analysis
  55. GRB 120927A: GROND upper limits
  56. GRB 120927A: Swift-XRT refined Analysis
  57. GRB 120927A: Enhanced Swift-XRT position
  58. GRB 120923A: JHK Observation
  59. GRB 120927A: Swift detection of a burst
  60. Further Swift-XRT observations of the GRB 120919A field.
  61. GRB 120923A: optical upper limit
  62. GRB 120921A: Fermi GBM detection of its 1000th GRB
  63. GRB 120916A Suzaku WAM observation of the prompt emission
  64. GRB 120923A: RAPTOR Limits During Gamma-Ray Emitting Interval
  65. GRB 120923A: CARMA Observations
  66. GRB 120923A: EVLA Observations
  67. GRB 120923A: Swift-XRT refined Analysis
  68. GRB 120923A: GROND Upper limits
  69. GRB 120922A: GROND photometric redshift
  70. GRB 120922A: Fermi GBM detection
  71. GRB 120922A: Swift/UVOT Detection
  72. GRB 120923A: Swift-BAT refined analysis
  73. GRB 120922A: Swift-BAT refined analysis
  74. GRB 120923A: Swift/UVOT Upper Limit
  75. GRB 120922A: Swift-XRT refined Analysis
  76. GRB 120922A: Swift/UVOT Observations
  77. GRB 120923A: Gemini afterglow detection, high-z candidate
  78. GRB 120923A: Enhanced Swift-XRT position
  79. GRB 120922A: Enhanced Swift-XRT position
  80. GRB 120922A: TAROT La Silla observatory optical observations
  81. GRB 120923A: TAROT La Silla observatory optical observations
  82. GRB 120923A: ROTSE-III Optical Limits
  83. GRB 120923A: Swift detection of a burst
  84. GRB 120922A: GROND afterglow candidate
  85. GRB 120922A: Prompt enhanced Swift-XRT position
  86. GRB 120922A: Swift detection of a burst
  87. GRB 120919B: MASTER prompt optical observations
  88. GRB 120919A: Swift/UVOT Upper Limits
  89. GRB 120919A: Swift-XRT observations
  90. Konus-Wind observation of GRB 120919B
  91. IPN Triangulation of long GRB 120919B
  92. Konus-Wind observation of GRB 120919A
  93. IPN Triangulation of long GRB 120919A
  94. GRB 120919A: Fermi GBM detection
  95. GRB 120918A: Swift-BAT refined analysis
  96. GRB 120916A: Fermi GBM Observation
  97. Konus-Wind observation of GRB 120916A
  98. Swift Trigger 534017 is probably not real.
  99. GRB 120918A: Swift detection of a burst
  100. IPN Triangulation of long GRB 120916A

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