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"

27029 results found.

  1. EP261003a: Einstein Probe detection of an X-ray transient
  2. GRB 261003A: Fermi GBM Final Real-time Localization
  3. Fermi-LAT Gamma-ray Observations of IceCube-260930A
  4. Fermi GBM Detection of GRB 260919A / EP260920a
  5. IPN triangulation of GRB 260919A / EP260920a
  6. GRB 260926C: SVOM/GRM observation
  7. GRB 260930B: Fermi GBM Final Real-time Localization
  8. GRB 260930A: Fermi GBM Final Real-time Localization
  9. IceCube-260930A - IceCube observation of a high-energy neutrino candidate track-like event
  10. The EP-WXT trigger 01709320790 is likely a flaring star
  11. EP260927a: SVOM/ECLAIRs Upper Limit
  12. GRB 260926C: AstroSat CZTI detection
  13. GRB 260926C: GECAM-B observation
  14. GRB 260926A: GECAM-B observation
  15. EP260927a: Einstein Probe detection of a fast X-ray transient
  16. GRB 260926B: Glowbug gamma-ray detection of a likely short burst
  17. GRB 260926A: Glowbug gamma-ray detection
  18. GRB 260924A: VLA detection
  19. GRB 260924A: AbAO optical observations
  20. GRB 260928A: Fermi GBM Final Real-time Localization
  21. GRB 260926C: Fermi GBM Final Real-time Localization
  22. GRB260914A: MAO/AZT-22 optical observations
  23. GRB 260926B: Fermi GBM Final Real-time Localization
  24. GRB 260926A: Fermi GBM Final Real-time Localization
  25. The EP-WXT trigger 01709320726 is likely a flaring star
  26. GRB 260924A: COLIBRÍ optical observations
  27. EP260924a: J-band upper limit by SYSU 80cm infrared telescope
  28. GRB 260925A: J-band upper limit by SYSU 80cm infrared telescope
  29. EP260924a: EP-FXT follow-up observation
  30. Swift Trigger 1513439 is probably not a GRB
  31. GRB 260925A: Swift/UVOT Upper Limits
  32. GRB 260924A: Extreme Isotropic-equivalent Gamma-ray Energy and encouragement for multiwavelength follow-up observations
  33. GRB 260923A: Glowbug gamma-ray detection
  34. GRB 260924A: Optical follow-up observations with Kinder
  35. GRB 260922A: Glowbug gamma-ray detection
  36. GRB 260925A: Enhanced Swift-XRT position
  37. GRB 260924A: Ondrejov D50 optical afterglow detection
  38. EP260924a: J-band upper limit with WINTER
  39. GRB 260924A: SVOM/GRM observation
  40. GRB 260924A: 2.2m CAHA spectroscopic redshift z = 3.51
  41. GRB 260925A: Swift detection of a burst
  42. GRB 260923A: Insight-HXMT/HE detection
  43. EP260924a: EP-WXT detection of an X-ray transient
  44. GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
  45. GRB 260924A: Swift/UVOT Detection
  46. GRB 260924A: GROWTH-India Telescope optical observations
  47. GRB 260924A: NuSTAR detection of prompt emission
  48. GRB 260922A: NuSTAR detection of prompt emission
  49. GRB 260921A: NuSTAR detection of prompt emission
  50. GRB 260921A: SVOM/GRM observation
  51. GRB 260922A: COLIBRÍ Confirmation of the Optical Counterpart
  52. GRB 260924A: Fermi GRB Observation
  53. GRB 260924A: Fermi-LAT detection of a bright burst
  54. GRB 260924A: AstroSat CZTI detection
  55. GRB 260920A: SVOM/GRM observation
  56. GRB 260924A: detection of a bright optical afterglow by the 1.5m OSN telescope
  57. GRB 260922A: CALET Gamma-Ray Burst Monitor detection
  58. GRB 260924A: Enhanced Swift-XRT position
  59. The EP-WXT trigger 01709319842 is likely a flaring star
  60. GRB 260924A: Swift detection of a burst
  61. GRB 260924A: Fermi GBM Final Real-time Localization
  62. GRB 260923A: Fermi GBM Final Real-time Localization
  63. EP260806a: e-MERLIN detection at 5 GHz
  64. GRB 260922A: Ondrejov D50 optical limit
  65. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  66. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  67. EP260920a: VLT/HAWK-I near-infrared counterpart confirmation
  68. GRB 260922A: J-band upper limit with WINTER
  69. GRB 260922A: Swift/UVOT Upper Limits
  70. GRB 260922A: Enhanced Swift-XRT position
  71. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  72. GRB 260920A: Glowbug gamma-ray detection
  73. GRB 260918A: SVOM/ECLAIRs refined analysis
  74. GRB 260922A: SVOM/C-GFT optical upper limit
  75. GRB 260922A: Swift detection of a burst
  76. GRB 260917C: AstroSat CZTI detection
  77. GRB 260920B/EP260920b: GECAM-B detection of a burst
  78. GRB 260921A: AstroSat CZTI detection
  79. GRB 260921B: Fermi GBM Final Localization
  80. GRB 260921A: Fermi GBM Observation
  81. EP260920b: 2.2m CAHA optical afterglow detection and 10.4m GTC redshift confirmation
  82. GRB 260917B:: SVOM/ECLAIRs refined analysis
  83. The EP-WXT trigger 01709319528 is likely a flaring star
  84. GRB 260921A: Fermi GBM Final Real-time Localization
  85. EP260920b: LCO observations
  86. GRB 260920A: AstroSat CZTI detection
  87. EP260920b: SVOM/VT optical observation
  88. EP260920b: refined analysis of the EP-WXT and EP-FXT observations
  89. EP260920b: COLIBRÍ optical observations
  90. EP260920b: LCO optical counterpart detection
  91. The EP-WXT trigger 01709318601 is likely a flaring star
  92. EP260920b: Einstein Probe detection of an X-ray transient
  93. EP-WXT detected a brightening of HMXB LS V +44 17
  94. EP260920a: NOT early time optical upper limits
  95. EP260920a: NOT optical upper limits
  96. GRB 260920A: Fermi GBM Final Real-time Localization
  97. EP260920a: SVOM/VT optical upper limits
  98. EP260920a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  99. EP260920a: COLIBRÍ optical upper limits
  100. EP260920a: Update of the LCO optical counterpart candidate

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