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"

24564 results found.

  1. LIGO/Virgo/KAGRA S230802aq: AstroSat CZTI non-detection and upper limits
  2. Fermi trigger No 712718833: Global MASTER-Net observations report
  3. GRB 230803A: Fermi GBM Final Real-time Localization
  4. Fermi trigger No 712713532: Global MASTER-Net observations report
  5. Fermi trigger No 712651827: Global MASTER-Net observations report
  6. GRB 230802B: Fermi GBM Final Localization
  7. Swift GRB 230802A: Global MASTER-Net observations report
  8. LIGO/Virgo/KAGRA S230802aq: Upper limits from Fermi-GBM Observations
  9. LIGO/Virgo S230802aq: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  10. LIGO/Virgo/KAGRA S230802aq: Coverage and upper limits from MAXI/GSC observations
  11. LIGO/Virgo/KAGRA S230802aq: Identification of a GW compact binary merger candidate
  12. IceCube-230724A: JCMT/SCUBA-2 submm observations
  13. LIGO/Virgo/KAGRA S230731an: Upper limits from Swift/BAT-GUANO
  14. LIGO/Virgo/KAGRA S230731an: AstroSat CZTI non-detection and upper limits
  15. LIGO/Virgo/KAGRA S230731an: not observable by Fermi-GBM
  16. LIGO/Virgo/KAGRA S230731an: Updated Sky Localization and EM Bright Classification, and Correction to Source Classification
  17. GRB 230731A: Fermi GBM Final Real-time Localization
  18. LIGO/Virgo/KAGRA S230731an: Coverage and upper limits from MAXI/GSC observations
  19. LIGO/Virgo/KAGRA S230731an: Identification of a GW compact binary merger candidate
  20. LIGO/Virgo/KAGRA S230729z: Updated Sky localization
  21. GRB 230723A: Detection of candidate millimeter-band radiation by SPT-3G
  22. Fermi trigger No 712390645: Global MASTER-Net observations report
  23. GRB 230728A: Swift-BAT refined analysis
  24. Fermi-LAT gamma-ray observations of IceCube-230727A
  25. GRB 230723B: Swift-BAT refined analysis
  26. Fermi trigger No 712306969: Global MASTER-Net observations report
  27. GRB 230723B: MITSuME Ishigaki optical observation
  28. IceCube-230727A: No candidates from the Zwicky Transient Facility
  29. LIGO/Virgo/KAGRA S230729z: Identification of a GW compact binary merger candidate
  30. IceCube-230727A: Upper limits from a search for additional neutrino events in IceCube
  31. GRB 230728A: Fermi GBM Observation
  32. GRB 230728A: LCOGT Optical Upper Limit
  33. GRB 230728A: Swift-XRT refined Analysis
  34. IceCube-230724A: No counterparts from the Zwicky Transient Facility
  35. Swift GRB230728.12: Global MASTER-Net observations report
  36. GRB 230727A: Swift/BAT-GUANO detection of a burst
  37. Fermi-LAT gamma-ray observations of IceCube-230725A
  38. Fermi-LAT gamma-ray observations of IceCube-230724A
  39. Fermi trigger No 712143685: Global MASTER-Net observations report
  40. IceCube-230727A - IceCube observation of a high-energy neutrino candidate track-like event
  41. GRB 230727A: Fermi GBM Final Real-time Localization
  42. IceCube-230725A: Upper limits from a search for additional neutrino events in IceCube
  43. IceCube-230724A: Upper limits from a search for additional neutrino events in IceCube
  44. Integral GRB230726.26: Global MASTER-Net observations report
  45. GRB 230723B: Further CAHA observations and host galaxy detection
  46. LIGO/Virgo/KAGRA S230726a: Updated Sky localization
  47. Konus-Wind detection of GRB 230723A
  48. GRB 230723B: MITSuME Akeno optical afterglow candidate detection
  49. LIGO/Virgo/KAGRA S230726b: one counterpart neutrino candidate from IceCube neutrino searches
  50. IceCube-230724A - IceCube observation of a high-energy neutrino candidate track-like event
  51. LIGO/Virgo/KAGRA S230726a: Identification of a GW compact binary merger candidate
  52. IBAS trigger number 10337: not a real GRB
  53. Integral GRB230725.99: Global MASTER-Net observations report
  54. IceCube-230725A - IceCube observation of a high-energy neutrino candidate track-like event
  55. IceCube Alert 230725.90: Global MASTER-Net observations report
  56. IPN triangulation of GRB 230723A (short)
  57. GRB 230725B: Fermi GBM Final Real-time Localization
  58. GRB 230725A: Fermi GBM Final Real-time Localization
  59. GRB 230723B: Fermi GBM observation
  60. GRB 230723B: non-detections from Observatoire de Haute-Provence
  61. IceCube Alert 230724.08: Global MASTER-Net observations report
  62. LIGO/Virgo/KAGRA S230723ac: Updated Sky localization
  63. Fermi trigger No 711853834: Global MASTER-Net observations report
  64. GRB 230724A: Fermi GBM Final Real-time Localization
  65. Fermi trigger No 711805358: Global MASTER-Net observations report
  66. GRB 230723B: Optical limit from CAHA
  67. Swift GRB 230723B: Global MASTER-Net observations report
  68. GRB 230723A: AGILE/MCAL detection
  69. LIGO/Virgo/KAGRA S230723ac: Identification of a GW compact binary merger candidate
  70. GRB 230723B: Swift detection of a burst
  71. Fermi GRB 230723A: Global MASTER-Net observations report
  72. GRB 230723A: Fermi GBM Final Real-time Localization
  73. Swift GRB230720.30: Global MASTER-Net observations report
  74. IPN triangulation of GRB 230715D
  75. GRB 230718A: Final Localization Correction
  76. GRB 230718A: Fermi GBM Final Real-time Localization
  77. IPN triangulation of GRB 230712C (short)
  78. IPN triangulation of GRB 230712A (short)
  79. LIGO/Virgo/KAGRA S230708z: Updated Sky localization
  80. GRB 230717A: Fermi GBM Final Real-time Localization
  81. Fermi trigger No 711088412: Global MASTER-Net observations report
  82. GRB 230715A: Fermi GBM Final Real-time Localization
  83. Fermi GRB 230713A: Global MASTER-Net observations report
  84. GRB 230713A: Fermi GBM Final Real-time Localization
  85. LIGO/Virgo/KAGRA S230709bi: Updated Sky localization
  86. LIGO/Virgo/KAGRA S230708t: Updated Sky localization
  87. GRB 230709B: CALET Gamma-Ray Burst Monitor detection
  88. GRB 230709C: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  89. IceCube-230708A: Upper limits from Swift/BAT-GUANO
  90. GRB 230712B: Fermi GBM Final Localization
  91. GRB 230707A: Swift/BAT-GUANO position correction
  92. GRB 230712A: Fermi GBM Final Real-time Localization
  93. IceCube-230708A - Correction to GCN Circular 34170
  94. Fermi trigger No 710741042: Global MASTER-Net observations report
  95. GRB 230709C: GRBAlpha detection
  96. GRB 230709B: GRBAlpha detection
  97. GRB 230709C: Fermi GBM Detection
  98. GRB 230709C: Fermi GBM Final Localization
  99. GRB 230707B: Fermi GBM Observation
  100. GRB 230710A: Fermi GBM Final Real-time Localization

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