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 110422A: Enhanced Swift-XRT position
  2. GRB 110422A: correction to the GCN circ. 11958
  3. GRB 110422A: TNG optical observations
  4. GRB 110422A: SAO RAS optical observations
  5. GRB 110422A: NOT optical observation
  6. GRB 110422A: MASTER earlier OT polarization observations
  7. GRB 110422A: Swift-BAT refined analysis
  8. GRB 110422A: Mondy optical observations
  9. GRB 110422A: Swift detection of a burst
  10. GRB 110328A/Swift J164449.3+573451: Maidanak Optical Observation
  11. GRB 110420B: Swift/UVOT Upper Limits
  12. GRB110420A: GROND detection of the Optical/NIR Afterglow Candidate
  13. GRB 110420B: Swift-XRT afterglow candidate retraction
  14. GRB 110420B: Fermi GBM observation
  15. Konus-Wind observation of GRB 110420A
  16. GRB 110420B: Spectral lag indicates short hard burst
  17. GRB 110420B, GROND observations
  18. GRB 110420A Swift/UVOT Observations
  19. GRB 110420B: Swift-XRT afterglow candidate
  20. GRB 110420B: Swift-BAT refined analysis
  21. GRB 110420A: Swift-BAT refined analysis
  22. GRB 110420B: Swift detection of a short hard burst
  23. GRB 110420A: Swift-XRT refined Analysis
  24. GRB 110420A: Enhanced Swift-XRT position
  25. GRB 110420A: Swift detection of a burst with optical counterpart
  26. GRB110414A: MITSuME Ishigakijima Optical upper limits
  27. GRB 110414A: GROND upper limits
  28. GRB110414A: MITSuME Okayama Optical upper limits
  29. GRB 110414A: Swift-BAT Refined Analysis
  30. GRB 110414A: Swift/UVOT Upper limits
  31. GRB 110414A: Swift-XRT refined Analysis
  32. GRB 110414A: Enhanced Swift-XRT position
  33. GRB 110328A / Swift J164449.3+573451: WISE quiescent source upper limit
  34. GRB 110414A : Faulkes Telescope North observations
  35. GRB 110414A: Swift detection of a burst
  36. GRB 110411A: PAIRITEL NIR Upper Limits
  37. GRB 110412A: Swift-BAT refined analysis
  38. GRB 110411A: optical limits from OSN
  39. GRB 110411A: Swift-XRT refined Analysis
  40. GRB 110412A: Fermi GBM observation
  41. GRB 110411A: Swift/UVOT Upper Limits
  42. GRB 110411A: MASTER prompt and follow-up optical limits
  43. GRB 110411A : Xinglong TNT OT candidate
  44. GRB 110412A: Swift detection of a burst
  45. GRB 110411A, Swift-BAT refined analysis
  46. GRB 110411A: Enhanced Swift-XRT position
  47. GRB 110411A: MASTER optical observations
  48. GRB 110411A: Swift detection of a burst
  49. GRB 110328A / Swift J164449.3+573451: R-band Monitoring
  50. GRB 110407A: Swift-XRT refined Analysis
  51. GRB 110328A / Swift J164449.3+573451: MASTER pre, prompt and follow-up observations
  52. GRB 110407A:VLF observations on 20.27kHz
  53. GRB 110328A / Swift J164449.3+573451: optical observations
  54. GRB 110407A: SMARTS optical limit
  55. GRB 110328A / Swift J164449.3+573451: VLBA Observations
  56. GRB 110328A/Swift J164449.3+573451 UVOT Upper Limits
  57. GRB 110406A: Positional coincidence with NGC 404
  58. GRB 110407A: MASTER optical observations
  59. GRB110407A: UVOT Upper Limits
  60. GRB 110407A: GROND Detection of the Optical Afterglow
  61. GRB 110407A: MITSuME Okayama and Ishigakijima Optical upper limits
  62. GRB 110407A: NOT optical observations
  63. GRB 110407A: Enhanced Swift-XRT position
  64. GRB 110407A: Swift-BAT refined analysis
  65. GRB 100407A : Errata of afterglow position in GCN 11899
  66. IPN triangulation of the bright GRB110406A
  67. GRB 110407A : Lulin optical afterglow detection
  68. GRB 110407A : Xinglong TNT upper limit
  69. GRB 110407A: MASTER early optical observations
  70. GRB 110407A: Prompt enhanced Swift-XRT position
  71. GRB 110407A: Swift detection of a burst
  72. Konus-Wind observation of GRB 110406A
  73. Redshift of GRB 110402A theoretically estimated (revised)
  74. GRB 110328A/Swift J164449.3+573451: BAT recent rate increase and pre-outburst,light curve
  75. GRB 110406A: An exceptionally bright burst detected by INTEGRAL SPI-ACS
  76. GRB 110402A: fading optical afterglow
  77. Redshift of GRB 110402A theoretically estimated
  78. GRB 110402A: Suzaku WAM observation of the prompt emission
  79. GRB 110328/Swift J164449.3+573451: Chandra observations
  80. GRB 110402A: LOAO Optical Observation
  81. ICSP VLF observation of multiple SGR-like bursts from 1E 1841-045 on Feb. 9, 2011
  82. Comparison of ICSP VLF observation of GRB 090424 with satellite observations
  83. GRB 110328A / Swift J164449.3+573451: Keck LRIS R-band photometry
  84. GRB 110328A / Swift J164449.3+573451, HST Observations
  85. GRB 110328A / Swift J164449.3+573451: millimeter detection at PdBI
  86. GRB 110402A: Konus-Wind spectral lags and detailed energetics
  87. GRB 110401A: Fermi GBM detection
  88. GRB 110402A: Fermi GBM detection
  89. GRB 110402A: optical observations in Mondy
  90. GRB 110402A afterglow observation
  91. GRB 110328A / Swift J164449.3+573451: Keck/DEIMOS Optical Spectroscopy
  92. GRB 110402A: MITSuME Okayama and Ishigakijima Optical upper limits
  93. GRB 110328A/Swift J164449.3+573451: SARA-N detection
  94. GRB 110402A: Swift/UVOT detection of afterglow candidate
  95. GRB 110402A: Spectral lag indicates short hard burst
  96. Konus-Wind observation of GRB 110402A
  97. GRB 110402A: Konkoly observations
  98. GRB 110328A: Konkoly observations.
  99. GRB 110402A: Swift-BAT refined analysis
  100. GRB 110402A: Swift-XRT refined Analysis

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