Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. 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"

19664 results found.

  1. GRB 221024A: GIT confirmation of the optical afterglow
  2. GRB 221024A: Enhanced Swift-XRT position
  3. GRB 221024A: D50 candidate afterglow
  4. GRB 221022B: AstroSat CZTI detection
  5. GRB 221022A: Fermi GBM detection
  6. GRB 221022A: Swift ToO observations
  7. GRB 221023A: Fermi-LAT detection
  8. GRB 221022B: Fermi GBM detection
  9. GRB 221021A: Fermi GBM observation
  10. GRB 221009A: Determination of the black holes mass and spin
  11. GRB 221024A: Swift detection of a burst
  12. GRB 221022A: Swift/BAT-GUANO detection
  13. GRB 221022B: Swift/BAT-GUANO detection outside the coded FOV
  14. GRB 221009A: optical observations, SN photometric evidence
  15. GRB 221021A: Swift/BAT-GUANO detection outside the coded FOV
  16. GRB 221017A: Swift-XRT observations
  17. Improved IPN localization for GRB 221009A (BepiColombo-MGNS light curve)
  18. GRB 221009A: BOAO NIR detections
  19. GRB 221009A X-ray light-curve and the indication of TeV light-curve
  20. GRB 221009A: Spectroscopic detection of emerging SN features
  21. GRB 221013B: Swift/BAT-GUANO detection
  22. AGILE detection of the 2022 October 17 burst from SGR J1935+2154 reported by Konus-Wind
  23. GRB 221009A: GRANDMA observations
  24. The probability of observing GRB 221009A at z = 0.151
  25. GRB 221017A: Swift ToO observations
  26. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  27. GRB 221009A: Second epoch of NuSTAR data
  28. GRB 221016A: Swift-BAT refined analysis
  29. GRB 221016A: Swift/UVOT Detection
  30. GRB 221016A: Swift-XRT refined Analysis
  31. Konus-Wind detection of GRB 221016A
  32. GRB 221016A: Fermi GBM observation
  33. GRB 221009A: A type I BdHN of exceptional energetics
  34. GRB 221016A: Enhanced Swift-XRT position
  35. GRB 221016A: Swift detection of a burst
  36. Swift GRB221016.99: Global MASTER-Net observations report
  37. GRB 221009A: Faulkes Telescope North continued optical afterglow follow-up
  38. GRB 221009A: continued Assy optical afterglow observations, possible SN evidence
  39. GRB 221009A: LEIA X-ray Afterglow Detection
  40. GRB 221009A: ATCA radio spectrum
  41. GRB 221009A: Armchair Energetics
  42. GRB 221009A: Fermi LAT data rate effects due to extremely high flux
  43. GRB 221009A: Large Binocular Telescope Observatory optical afterglow detection
  44. GRB 221009A: Pan-STARRS optical photometry
  45. MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946
  46. GRB 221009A: continued REM optical/NIR observations and evidence for an achromatic steepening in the afterglow light curve
  47. GRB 221009A: HEBS detection
  48. GRB 221009A: Gamma-ray Detection by SIRI-2
  49. GRB221009A: Detection as sudden ionospheric disturbances (SID)
  50. GRB 221009A: search for neutrinos with KM3NeT
  51. GRB221009A: LCOGT Continued Observations - Optical Upper Limits
  52. GRB 221009A/Swift J1913.1+1946: low-frequency ASKAP observations
  53. GRB 221006A: Swift-XRT afterglow detection
  54. GRB 221009A: MITSuME Okayama optical observation
  55. GRB 221009A: Sayan observatory 1.6-m telescope observations
  56. GRB 221009A/Swift J1913.1+1946: SMA observations
  57. GRB 221009A/Swift J1913.1+1946: eMERLIN observations
  58. INTEGRAL detection of a burst from SGR J1935+2154
  59. GRB 221009A: NuSTAR Detection
  60. GRB 221009A: LCOGT Optical Afterglow Detection
  61. GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger
  62. GRB 221009A (Swift J1913.1+1946): Swift-BAT refined analysis
  63. GRB 221009A: 10.4m GTC spectroscopic redshift confirmation
  64. GRB 221009A: Detection by GRBAlpha
  65. GRB 221009A: Sintez-Newton/CrAO optical observations
  66. GRB 221009A: Upper limits from HAWC 8 hours after trigger
  67. GRB 221006A: Swift ToO observations
  68. Swift/XRT discovery of multiple dust-scattering X-ray rings around GRB 221009A
  69. GRB 221009A (Swift J1913.1+1946): iTelescope optical observation
  70. LHAASO observed GRB 221009A with more than 5000 VHE photons up to around 18 TeV
  71. GRB 221009A: Continued Swift/XRT observations
  72. GRB 221009A/Swift J1913.1+1946: Assy optical afterglow observation
  73. GRB 221009A/Swift J1913.1+1946: Lick/Nickel telescope optical observations
  74. GRB 221009A: Lulin SLT-40cm optical observations
  75. Swift J1913.1+1946: New Photometry
  76. GRB 221009A: Upper limits from a neutrino search with IceCube
  77. GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
  78. GRB221009A/Swift J1913.1+1946: SRG/ART-XC observation
  79. GRB 221009A / Swift J1913.1+1946: GIT detection of the optical afterglow
  80. GRB221009A/Swift J1913.1+1946: Solar Orbiter STIX measurements
  81. GRB221009A/Swift J1913.1+1946: INTEGRAL SPI/ACS observations
  82. GRB 221009A: Fermi-LAT refined analysis
  83. GRB 221009A (Swift J1913.1+1946): AGILE/GRID detection
  84. GRB 221009: Swift/UVOT Detection
  85. GRB221009A/Swift J1913.1+1946: ATA follow-up observations
  86. GRB 221009A or Swift J1913.1+1946: PRIME near-infrared detection
  87. GRB 221009A/Swift J1913.1+1946: AMI-LA observations
  88. GRB 221009A: Swift-XRT refined Analysis
  89. GRB 221009A (Swift J1913.1+1946): AGILE/MCAL detection
  90. Swift J1913.1+1946: Early Optical Photometry
  91. GRB 221009A: Nanshan/NEXT photometry and Xinglong-2.16m spectroscopy
  92. GRB 221009A (Swift J1913.1+1946): MeerLICHT observations
  93. GRB 221009A (Swift J1913.1+1946): Mondy optical observations
  94. GRB 221009A BOOTES-2/TELMA and OSN optical detections
  95. Swift J1913.1+1946 : Pre-discovery limits from ZTF
  96. GRB 221009A: Fermi GBM observation
  97. IPN triangulation of extremely bright GRB 221009A
  98. Swift J1913.1+1946: Optical photometry
  99. Swift J1913.1+1946: Liverpool Telescope imaging and spectroscopy
  100. GRB 221009A or Swift J1913.1+1946: Fermi-LAT 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