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"

23733 results found.

  1. LIGO/Virgo/KAGRA S231119u: Identification of a GW compact binary merger candidate
  2. GRB 231117A: MAAO 0.7-m telescope optical upper limit
  3. GRB 231117A: AKO Follow-Up Observation
  4. GRB 231117A: GECAM-C detection
  5. GRB 231115A: Upper limit from CALET Gamma-Ray Burst Monitor
  6. GRB 231118A: Las Cumbres optical detection
  7. GRB 231118A: MASTER OT observation
  8. Swift GRB231118.72: Global MASTER-Net observations report
  9. GRB 231117A: Kinder observations with Lulin observatory for AT 2023yba without fading in r band
  10. GRB 231118A: Swift detection of a burst
  11. GRB 231117A: ePESSTO+ host galaxy redshift confirmation
  12. LIGO/Virgo/KAGRA S231118an: Identification of a GW compact binary merger candidate
  13. GRB 231117A: GRBAlpha detection
  14. LIGO/Virgo/KAGRA S231118ab: Identification of a GW compact binary merger candidate
  15. GRB 231117A: Keck spectroscopy of afterglow candidate
  16. LIGO/Virgo/KAGRA S231118d: Identification of a GW compact binary merger candidate
  17. GRB 231117A: GIT optical follow-up
  18. GRB231117A: AGILE/MCAL analysis
  19. GRB 231117A: AKO Optical Upper Limit
  20. GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
  21. Swift GRB 231117A: Global MASTER-Net observations report
  22. GRB 231117A (short): Glowbug gamma-ray detection
  23. GRB 231117A: ATLAS non-detection of an optical counterpart
  24. Konus-Wind detection of GRB 231117A (short/hard)
  25. GRB 231115A: optical observations from INAF observatories
  26. GRB 231117A : MITSuME Akeno optical upper limits
  27. GRB 231117A: AGILE detection of a bright short burst
  28. GRB 231117A: GOTO optical upper limits
  29. GRB 231117A: AstroSat CZTI detection of a bright short burst
  30. GRB 231117A: Swift detection of a bright short burst
  31. GRB231115A: Liverpool Telescope imaging
  32. GRB 231115A: NuSTAR Follow-Up Observations
  33. Fermi GRB 231116A: Global MASTER-Net observations report
  34. Konus-Wind detection of GRB 231115A (a probable Magnetar Giant Flare from M82)
  35. GRB 231115A: AGILE/MCAL upper limits
  36. GRB 231115A : MITSuME Akeno and Okayama optical upper limits
  37. GRB 231115A / AT2023xvj: Updated GIT analysis
  38. GRB 231115A: Kinder observations with Lulin observatory
  39. GRB231115A: GRANDMA Observations
  40. GRB 231115A: GOTO pre-burst limits of AT2023xvj
  41. GRB 231115A: MASTER optical observations
  42. GRB 231115A (short): Glowbug gamma-ray detection
  43. Integral GRB231115.65: Global MASTER-Net observations report
  44. GRB 231115A: GROWTH-India discovery of a potential optical counterpart
  45. Fermi GRB 231115A: Global MASTER-Net observations report
  46. GRB 231115A position consistent with M 82 galaxy
  47. GRB 231111A: Swift-BAT refined analysis
  48. Fermi GRB 231114A: Global MASTER-Net observations report
  49. GRB 231113A (short): Glowbug gamma-ray detection
  50. GRB 231114A (short): Glowbug gamma-ray detection
  51. LIGO/Virgo S231113bw: upper limits from AGILE/MCAL
  52. LIGO/Virgo/KAGRA S231114n: Identification of a GW compact binary merger candidate
  53. GRB 231110A: CALET Gamma-Ray Burst Monitor detection
  54. LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
  55. LIGO/Virgo/KAGRA S231113bw: Coverage and upper limits from MAXI/GSC observations
  56. LIGO/Virgo/KAGRA S231113bw: Identification of a GW compact binary merger candidate
  57. GRB 231110A: Swift-BAT refined analysis
  58. GRB 231106A: Glowbug gamma-ray detection
  59. LIGO/Virgo/KAGRA S231113bb: Identification of a GW compact binary merger candidate
  60. GRB 231111A: Afterglow redshift from OSIRIS+/GTC
  61. GRB 231104A: VZLUSAT-2 detection
  62. GRB 231111A: TNG tentative redshift
  63. GRB 231110A: Glowbug gamma-ray detection
  64. GRB 231110A: AstroSat CZTI detection
  65. GRB 231111A NUTTelA-TAO / BSTI Early Measurements
  66. GRB231111A: Optical follow-up observations with Mephisto
  67. GRB 231111A: GMG observation (correction)
  68. GRB 231111A: GMG observation upper limit
  69. GRB 231106B: GRBAlpha detection
  70. GRB 231110A: GECAM-B detection (correction)
  71. GRB 231110A: GECAM detection
  72. GRB 231110A: GOTO optical upper limits
  73. GRB 231110A: SAO RAS optical observations
  74. GRB 231110A: Swift-XRT afterglow detection
  75. GRB 231111A: MASTER OT earlier detection
  76. GRB 231111A: Nanshan/HMT optical observations
  77. GRB 231111A: Swift detection of a burst with an optical counterpart
  78. Swift GRB231111.60: Global MASTER-Net observations report
  79. Swift GRB231110.89: Global MASTER-Net observations report
  80. GRB 231110A: Swift detection of a burst
  81. LIGO/Virgo/KAGRA S231110g: Identification of a GW compact binary merger candidate
  82. Fermi trigger No 721204446: Global MASTER-Net observations report
  83. Fermi GRB 231108A: Global MASTER-Net observations report
  84. LIGO/Virgo/KAGRA S231108u: Identification of a GW compact binary merger candidate
  85. GRB 231106A: CALET Gamma-Ray Burst Monitor detection
  86. GRB 231104A: Swift-BAT refined analysis
  87. Fermi trigger No 721006392: Global MASTER-Net observations report
  88. Fermi GRB 231106A: Global MASTER-Net observations report
  89. GRB 231104A: NuSTAR Observation of the prompt emission
  90. GRB 231106A: Fermi GBM Final Real-time Localization
  91. LIGO/Virgo/KAGRA S231106y: one counterpart neutrino candidate from IceCube neutrino searches
  92. GRB 231104A: NOT upper limit
  93. Fermi GRB 231103A: Global MASTER-Net observations report
  94. GRB 231104A: AstroSat CZTI detection
  95. GRB 231104A: Swift-XRT refined Analysis
  96. GRB 231104A: Swift/UVOT Upper Limits
  97. GRB 231104A: Swift detection of a bright burst
  98. Swift GRB231104.07: Global MASTER-Net observations report
  99. IceCube Alert 231103.39: Global MASTER-Net observations report
  100. LIGO/Virgo/KAGRA S231102i: Global MASTER-Net observations report

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