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 140108A: Swift/UVOT Detection
  2. GRB 140108A: theoretical prediction of redshift and of supernova occurrence
  3. GRB 140108A: Swift-XRT refined Analysis
  4. GRB 140108A: Enhanced Swift-XRT position
  5. GRB 140108A: Mondy optical observations
  6. GRB 140108A: D50+BART optical candidate detection
  7. GRB 140108A: 1.23m CAHA observations
  8. GRB 140108A: MASTER-Net OT detection
  9. GRB 140108A: Prompt enhanced Swift-XRT position
  10. GRB 140108A: Swift detection of a burst
  11. New Fermi-LAT GRB Table
  12. GRB 140105A: HCT Observations
  13. GRB 140105A: continued iPTF observations and rejection of optical candidates
  14. Swift-BAT triggered on KS 1947+300
  15. GRB 140105A: Swift XRT observations
  16. GRB 140103A: Swift XRT afterglow confirmation
  17. GRB 140105A/Fermi410578384: MASTER-Net early optical observations
  18. GRB 140104B: Swift XRT observations
  19. GRB 140102A: Swift/UVOT Detection
  20. LOAO R-band Observation of GRB 140102A
  21. GRB 140105A: Fermi GBM detection
  22. GRB 140104B: Fermi GBM observation
  23. Fermi410578384: iPTF optical afterglow candidates for a possible short GRB
  24. GRB 140102A: BOOTES-4 early optical observations
  25. GRB 140104B: Fermi-LAT detection of a burst
  26. GRB 131209A: Further Swift XRT observations
  27. GRB 140103A: Lulin Optical r-band Observations
  28. GRB 131231A : Lulin Optical Observations
  29. GRB 131231A: CARMA 3mm detection
  30. Swift-BAT trigger 582894 is HR 1099 (Flare star)
  31. GRB140104A : Xinglong TNT observation. A bright star is located nearby
  32. GRB 140102A, Optical Observations
  33. GRB 131231A, Optical Observations
  34. GRB 140103A: P60 Observations
  35. GRB 140102A: P60 observations
  36. GRB 131231A: Swift/UVOT Observations of the Optical Afterglow
  37. GRB 131231A: Fermi GBM correction to GCN 15644
  38. GRB 140103A: Swift/UVOT Upper Limits
  39. Konus-Wind observation of GRB 131231A
  40. GRB 140102A: Fermi/GBM Observation
  41. GRB 131229A: Suzaku WAM observation of the prompt emission
  42. Konus-Wind observation of GRB 140102A
  43. GRB 140103A: Swift-XRT refined analysis
  44. GRB 140102A: GROND observations
  45. GRB 140103A, Swift-BAT refined analysis
  46. GRB 140102A: MAXI/GSC detection
  47. GRB 140102A, Swift-BAT refined analysis
  48. GRB 140102A: Swift-XRT refined Analysis
  49. GRB 140103A: MASTER-Net optical observations
  50. GRB 140102A: Fermi-LAT detection of a burst
  51. GRB 140102A: I-band observations from IAC80 and 1.23m CAHA telescopes
  52. GRB 140102A: Enhanced Swift-XRT position
  53. GRB 140103A: Swift detection of a burst
  54. GRB 140102A: Early optical observations from Nanshan
  55. GRB 131224B detected in ground analysis of Swift-BAT data
  56. GRB 140102A: Swift detection of a burst with optical counterpart
  57. GRB 131231A: Gemini-South Redshift
  58. GRB 131229A: Fermi GBM detection
  59. GRB 131231A: P60 observations
  60. GRB 131227A: KAIT light curve analysis
  61. GRB 131231A: Swift-XRT observations
  62. GRB 131231A : xinglong TNT optical observation
  63. GRB 131231A: MDM afterglow observation
  64. GRB 131231A: VLT/X-shooter redshift
  65. GRB 131231A: Fermi GBM detection
  66. GRB 131231A: iPTF optical afterglow candidate coincident with Nanshan detection
  67. GRB 131231A: afterglow confirmation from the NOT
  68. GRB 131231A: Nanshan afterglow candidate
  69. GRB 131231A: Fermi-LAT detection of a burst
  70. Konus-Wind observation of GRB 131229A
  71. GRB 131229A: CARMA 3mm observations
  72. GRB 131229A: Magellan upper limit
  73. GRB 131229A: GROND observations
  74. GRB 131229A: Swift-BAT refined analysis
  75. GRB 131229A: Swift-XRT refined Analysis
  76. GRB 131229A: Swift/UVOT Upper Limits
  77. GRB 131227A: GROND Upper Limits
  78. GRB 131229A: Enhanced Swift-XRT position
  79. GRB 131229A: Deep Gemini-South Imaging
  80. GRB 131229A: KAIT Optical Upper Limit
  81. GRB 131229A: P60 nondetection
  82. GRB 131229A: Swift detection of a burst
  83. GRB 131224A: 5.8 GHz VLA observations
  84. GRB 131227A: P60 Limits
  85. GRB 131227A: Gemini-North Redshift
  86. GRB 131227A: Swift-XRT refined Analysis
  87. GRB 131227A: Xinglong optical observations
  88. GRB 131227A: Swift/UVOT Upper Limits
  89. GRB 131227A: Swift-BAT refined analysis
  90. Konus-Wind observation of GRB 131226A
  91. GRB 131227A: Enhanced Swift-XRT position
  92. GRB 131227A: OT candidate from KAIT Optical observations
  93. GRB 131227A: Swift detection of a burst
  94. GRB 131224A: Swift/UVOT Upper Limits
  95. GRB 131225A: MASTER-Net optical observations
  96. GRB 131226A, Swift-BAT refined analysis
  97. GRB 131226A: Swift detection of a burst
  98. GRB 131216A: Suzaku WAM observation of the prompt emission
  99. GRB 131224A: Swift-XRT observation
  100. GRB 131225A: MAXI/GSC detection

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