Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

37705 results found.

  1. GRB161219.78 MASTER-Net OT detection
  2. Fermi GBM trigger 504061556/161222046 is not a GRB
  3. GRB 161219B: Rapid ALMA Observations & Detection
  4. Correction to GCN 20323 "Konus-Wind observation of GRB 161219B"
  5. Fermi GBM trigger 504043585/161221838 is not a GRB
  6. GRB 161220A: Swift-BAT refined analysis
  7. GRB 161218B: Astrosat CZTI detection
  8. Konus-Wind observation of GRB 161219B
  9. GRB 161219B: SALT observations
  10. GRB 161219B: VLT/X-shooter redshift
  11. Fermi GBM trigger 503982114/161221126 is not a GRB
  12. GRB 161214B: optical spectroscopy of the foreground SDSS object
  13. GRB 161202A: 15 GHz upper limits from AMI
  14. GRB 161129A: 15 GHz upper limits from AMI
  15. GRB 161220A: Swift-XRT refined Analysis
  16. GRB 161220A: LCO-FTS observations
  17. GRB 161219B: MITSuME Akeno Optical Observation
  18. GRB 161219B: VLA Detection
  19. GRB 161220A: GROND Upper Limits
  20. GRB 161217C: POLAR observation
  21. GRB 161217B: POLAR Observation
  22. GRB 161219B: ISON/Terskol optical observations
  23. GRB 161219B: Swift-BAT refined analysis
  24. GRB 161220A: Swift/UVOT Upper Limits
  25. GRB 161219B: Swift/UVOT Detection
  26. GRB 161219B: Watcher optical observations
  27. Konus-Wind observation of GRB 161218B
  28. IPN Triangulation of GRB 161218B (long/very bright)
  29. GRB 161220A: Swift detection of a burst
  30. GRB 161212A: POLAR Detection
  31. GRB 161219B: LCO Sutherland observations
  32. GRB 161219B: GROND afterglow observations
  33. GRB 161219B: Swift-XRT refined Analysis
  34. GRB 161219B: Enhanced Swift-XRT position
  35. GRB 161219B: Swift detection of a burst with an optical afterglow
  36. GRB 161219A: a long GRB detected by INTEGRAL
  37. GRB 161218A: CALET Gamma-Ray Burst Monitor detection
  38. GRB 161218A: Swift-BAT refined analysis
  39. Konus-Wind observation of GRB 161218A
  40. GRB 161218A: TAROT Calern observatory optical observations
  41. GRB 161217A: TAROT Calern observatory optical observations
  42. GRB 161218B: POLAR observation
  43. GRB 161218A: POLAR observation
  44. GRB 161218B: Fermi GBM detection
  45. GRB 161217A: MITSuME Okayama upper limits
  46. GRB 161217A: Swift-BAT refined analysis
  47. GRB 161218A: Swift detection of a burst
  48. GRB 161217A: Swift/UVOT Upper Limits
  49. GRB 161217A: Swift-XRT refined Analysis
  50. GRB 161214B: AbAO and ISON/Terskol optical observations
  51. GRB 161217A: Enhanced Swift-XRT position
  52. GRB 161207A: POLAR observation
  53. GRB 161217A: Swift detection of a burst
  54. GRB 161214B: Mondy optical observations
  55. GRB 161213A: POLAR Observation
  56. GRB 161207B: POLAR observation
  57. GRB 161205A: POLAR observation
  58. GRB 161210A: POLAR observation
  59. GRB 161214B: Swift-BAT refined analysis
  60. Fermi-LAT Gamma-ray Observations of IceCube-161210
  61. GRB 161214B: Swift/UVOT Afterglow Confirmation
  62. GRB 161214B: RATIR Optical and Near-Infrared Observations
  63. GRB 161214B: Swift-XRT refined Analysis
  64. GRB 161214B: Enhanced Swift-XRT position
  65. GRB 161214B: TAROT Calern observatory optical observations
  66. GRB 161214B: Chante-perdrix observatory optical observations
  67. GRB 161214B: Swift/UVOT Observations
  68. GRB 161214B: NOT optical observations, possible counterpart
  69. GRB 161214B: Prompt enhanced Swift-XRT position
  70. GRB 161214A: NOT observations of the afterglow
  71. GRB 161214B: Swift detection of a burst
  72. IceCube-161210: Konus-Wind upper limits
  73. GRB 161214A: GROND afterglow observations
  74. GRB 161214A: TAROT Calern observatory optical observations
  75. GRB 161214A: fading optical afterglow candidate with the LT
  76. GRB 161214A: A long GRB detected by INTEGRAL
  77. INTEGRAL SPI-ACS and IBIS/Veto observation of IceCube-161210
  78. GRB 161207A: CALET Gamma-Ray Burst Monitor detection
  79. GRB 161129A: GTC redshift of the likely host galaxy
  80. GRB 161129A: NOT optical observations and candidate host galaxy
  81. GRB 161203A: POLAR Detection
  82. GRB 161129A: KWFC z-band photometry
  83. GRB 161203A: Astrosat CZTI (Veto) detection
  84. GRB 161203A: CALET Gamma-Ray Burst Monitor detection
  85. GRB 161206A: Fermi GBM detection
  86. Konus-Wind observation of GRB 161202A
  87. MASTER: Optical Blazar Flare Detection during Fermi trigger 502272781 inspection
  88. GRB 161129A: POLAR Detection
  89. GRB 161202A: Astrosat CZTI detection
  90. GRB 161202A: RATIR Optical and NIR Observations
  91. GRB 161202A: Swift-BAT refined analysis
  92. GRB 161202A: Swift/UVOT Upper Limits
  93. GRB 161202A: Swift-XRT refined Analysis
  94. GRB 161202A: MITSuME Okayama upper limits
  95. GRB 161202A: Fermi-LAT detection
  96. GRB 161202A: Enhanced Swift-XRT position
  97. GRB 161202A: Swift detection of a burst
  98. GRB 161129A: Mondy optical observations
  99. Fermi GBM trigger 502258294/161201175 is not a GRB
  100. GRB 161129A: ISON/UAFO optical observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov