Skip to main content
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 140129A, Swift-BAT refined analysis
  2. GRB 140129A: Swift/UVOT Observations
  3. GRB 140129A: Swift-XRT refined Analysis
  4. GRB 140129B: MASTER OT confirmation
  5. GRB 140129B: Swift detection of a burst with an optical afterglow
  6. GRB 140129A: Enhanced Swift-XRT position
  7. GRB 140129A: ROTSE-III Detection of Optical Counterpart
  8. GRB 140129A: RATIR Optical and NIR Observations
  9. GRB 140129A: P60 optical afterglow detection
  10. GRB 140129A: Swift detection of a burst with an optical afterglow
  11. GRB 140122A/Fermi412093190: MASTER-Net early optical observations
  12. Fermi412093190: iPTF optical counterpart search
  13. GRB 140110A: Second Follow-up Swift-XRT Observation
  14. GRB 140114A: optical upper limit
  15. Correction: MAXI J1421-613: Skynet PROMPT/R-COP observations
  16. Konus-Wind observation of GRB 131215A
  17. GRB 140118A/MAXI J1421-613: Skynet PROMPT/R-COP observations
  18. GRB 140118A: RATIR Optical and NIR Observations
  19. GRB 140118A: Fermi GBM observation
  20. GRB 140118A, Swift-BAT refined analysis
  21. Swift Trigger 584155 is MAXI J1421-613
  22. GRB 140118A: Swift detection of a burst
  23. GRB 140110A: Further Swift-XRT Observation
  24. GRB 140103A: MASTER-Net early OT detection
  25. GRB 140103A: optical upper limit
  26. GRB 140108A: Mondy optical observations, refined analysis
  27. GRB 140114A: NOT afterglow observations
  28. GRB 140114A: Continued RATIR Optical and NIR Observations
  29. GRB 140114A: MITSuME Okayama upper limits
  30. GRB 140114A: ROTSE-III Optical Limits
  31. GRB 140114A: Swift-XRT refined Analysis
  32. GRB 140114A: Swift-BAT refined analysis
  33. GRB 140114A: Swift/UVOT Upper Limits
  34. GRB 140114A: KAIT Optical Upper Limit
  35. GRB 140103A: AAO optical afterglow candidate
  36. GRB 140104B: Further Swift XRT observations
  37. GRB 140114A: Enhanced Swift-XRT position
  38. GRB 140114A: RATIR Optical and NIR Afterglow Detection
  39. Fermi Gamma-ray Burst Monitor trigger 411362827 is not a GRB
  40. GRB 140102A: AAO optical upper limits
  41. GRB 140114A: P60 Observations
  42. GRB 140114A: Swift detection of a burst
  43. GRB 140108A: Konkoly optical observations
  44. GRB 140110A: Swift/UVOT retraction of UVOT candidates
  45. IPN Triangulation of GRB 140110A
  46. GRB 140110A: Swift/UVOT Observations
  47. GRB 140108A: Suzaku WAM observation of the prompt emission
  48. GRB 140104B: Suzaku WAM observation of the prompt emission
  49. GRB 140110A: Swift XRT observations
  50. GRB 140110A: Reported UVOT OT not GRB afterglow
  51. GRB 140110A: OT detection in Swift/UVOT imaging
  52. GRB 140108A BAT refined analysis update *CORRECTION*
  53. GRB 140108A BAT refined analysis update
  54. GRB 140110A: Fermi GBM observation
  55. GRB 140110A Tiled Swift observations
  56. GRB 140110A: Fermi-LAT detection of a burst
  57. GRB 140108A: Mondy optical upper limit
  58. GRB 140105A: MASTER-Net early optical observations and time correction
  59. GRB 131231A: AAO optical observations
  60. GRB 140108A: Swift-BAT refined analysis
  61. GRB 140108A: Fermi GBM detection
  62. GRB 140108A: Swift/UVOT Detection
  63. GRB 140108A: theoretical prediction of redshift and of supernova occurrence
  64. GRB 140108A: Swift-XRT refined Analysis
  65. GRB 140108A: Enhanced Swift-XRT position
  66. GRB 140108A: Mondy optical observations
  67. GRB 140108A: D50+BART optical candidate detection
  68. GRB 140108A: 1.23m CAHA observations
  69. GRB 140108A: MASTER-Net OT detection
  70. GRB 140108A: Prompt enhanced Swift-XRT position
  71. GRB 140108A: Swift detection of a burst
  72. New Fermi-LAT GRB Table
  73. GRB 140105A: HCT Observations
  74. GRB 140105A: continued iPTF observations and rejection of optical candidates
  75. Swift-BAT triggered on KS 1947+300
  76. GRB 140105A: Swift XRT observations
  77. GRB 140103A: Swift XRT afterglow confirmation
  78. GRB 140105A/Fermi410578384: MASTER-Net early optical observations
  79. GRB 140104B: Swift XRT observations
  80. GRB 140102A: Swift/UVOT Detection
  81. LOAO R-band Observation of GRB 140102A
  82. GRB 140105A: Fermi GBM detection
  83. GRB 140104B: Fermi GBM observation
  84. Fermi410578384: iPTF optical afterglow candidates for a possible short GRB
  85. GRB 140102A: BOOTES-4 early optical observations
  86. GRB 140104B: Fermi-LAT detection of a burst
  87. GRB 131209A: Further Swift XRT observations
  88. GRB 140103A: Lulin Optical r-band Observations
  89. GRB 131231A : Lulin Optical Observations
  90. GRB 131231A: CARMA 3mm detection
  91. Swift-BAT trigger 582894 is HR 1099 (Flare star)
  92. GRB140104A : Xinglong TNT observation. A bright star is located nearby
  93. GRB 140102A, Optical Observations
  94. GRB 131231A, Optical Observations
  95. GRB 140103A: P60 Observations
  96. GRB 140102A: P60 observations
  97. GRB 131231A: Swift/UVOT Observations of the Optical Afterglow
  98. GRB 131231A: Fermi GBM correction to GCN 15644
  99. GRB 140103A: Swift/UVOT Upper Limits
  100. Konus-Wind observation of GRB 131231A

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