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"

19725 results found.

  1. GRB 240329A: AstroSat CZTI detection
  2. X-ray transient EP240315a: continued ATCA monitoring
  3. GRB 240328C: Glowbug gamma-ray detection
  4. X-ray transient EP240315a: Ondrejov D50 optical limit
  5. Transient EPW20240219aa: REM optical/NIR further observations
  6. GRB 240320A: Glowbug gamma-ray detection
  7. GRB 240318A: Fermi GBM Observation
  8. X-ray transient EP240315a: ATCA detection of radio counterpart
  9. IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a)
  10. X-ray transient EP240315a: MeerKAT radio detection
  11. GRB 240318A: Glowbug gamma-ray detection
  12. GRB 240317C: Glowbug gamma-ray detection
  13. GRB 240318B: Glowbug gamma-ray detection
  14. X-ray transient EP240315a: PRIME near infrared detection
  15. X-ray transient EP240315a: 3.6 m TNG NIR detection
  16. X-ray transient EP240315a/AT2024eju: TShAO (Zeiss-1000) observatory optical upper limit
  17. GRB 240317A: AstroSat CZTI detection
  18. X-ray transient EP240315a: Kitab observatory optical upper limitns
  19. X-ray transient EP240315a: Montarrenti Observatory optical upper limit
  20. X-ray transient EP240315a: orphan FXT?
  21. X-ray transient EP240315a: Kinder follow-up observations for AT 2024eju with Lulin observatory
  22. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  23. X-ray transient EP240315a: Nanshan/HMT optical upper limit
  24. Einstein Probe detected of a fast X-ray transient EP240315a
  25. Changes to the Fermi-GBM Triggering Thresholds
  26. GRB240204A: VIRT optical upper limit
  27. GRB 240312A: Glowbug gamma-ray detection
  28. Fermi-LAT gamma-ray observations of IceCube-240307A
  29. GRB 240310B: Glowbug gamma-ray detection
  30. GRB 231215A: further radio observations with the VLA
  31. GRB 240229A: Glowbug gamma-ray detection
  32. GRB 240227A (short): Glowbug gamma-ray detection
  33. Fermi-LAT gamma-ray observations of IceCube-240229A
  34. GRB 231028C: Glowbug gamma-ray confirmation of a prior burst
  35. GRB 240218A: Chandra Detection and Jet Break Confirmation
  36. Swift Trigger 1218701: Yes, we triggered on Swift J151857.0-572147 again
  37. GRB240218A: ATCA observation of the radio counterpart
  38. GRB 240225B: Swift-XRT afterglow detection
  39. Swift detection of Swift J151857.0-572147
  40. Swift J151857.0-572147: Confirmation of a new galactic transient
  41. GRB 240303A: Swift detection of a burst
  42. GRB 240225B: Glowbug gamma-ray detection
  43. GRB 240225C: Glowbug gamma-ray detection
  44. GRB 240225A (short): Glowbug gamma-ray detection
  45. GRB 240229A: DDOTI Upper Limits on the Afterglow
  46. GRB 240218A: NOEMA upper limit
  47. GRB 240225B: further SAO RAS optical observations
  48. GRB 240225B: Swift ToO observations
  49. GRB 240225B: VLT/X-shooter redshift
  50. GRB 240225B : MITSuME Akeno optical afterglow candidate detection
  51. GRB 240225B: 3.6m DOT observation
  52. GRB 240225B: WINTER near-IR observations and upper limits
  53. GRB 240225B: SAO RAS optical observations
  54. GRB 240225B: Mondy afterglow observations
  55. GRB 240218A: CMO SAI NIR upper limit
  56. GRB 240225B: Nanshan/HMT optical afterglow detection
  57. GRB 240225B: Swift-XRT observations
  58. Transient EPW20240219aa: Kp-band imaging observations with NIRES
  59. Transient EPW20240219aa: REM optical/NIR upper limits
  60. GRB 240225B: Tiled Swift observations
  61. Transient EPW20240219aa: Xinglong-2.16m optical upper limit
  62. Transient EPW20240219aa: GECKO: LOAO Optical Upper Limits
  63. Transient EPW20240219aa: 7DT Optical Upper Limits
  64. Transient EPW20240219aa: Mondy optical observations
  65. Transient EPW20240219aa: Liverpool Telescope non-detection and limiting magnitude
  66. GRB 240222A: Swift/UVOT Upper Limits
  67. GRB 240222A: REM optical and NIR early-time observations
  68. GRB 240222A: Swift detection of a burst
  69. GRB 240218A: MeerLICHT upper limits
  70. GRB 240216A: Glowbug gamma-ray detection
  71. GRB 240218A: LBT H-band detection
  72. GRB 240218A: VLT/X-shooter redshift of z = 6.782
  73. GRB 240218A: Enhanced Swift-XRT position
  74. GRB 240218A: REM detection of a NIR afterglow candidate
  75. Gamma-ray flaring activity from the blazar 1ES 1959+650 observed by the Fermi-LAT
  76. GRB 240218A : r-band upper limit from Observatoire de Haute-Provence
  77. GRB240218A: VLT/X-shooter upper limits
  78. GRB 240218A: Swift detection of a burst
  79. GRB 240215A: Tiled Swift observations
  80. GRB 240213A: Glowbug gamma-ray detection
  81. GRB 240128A: Further Swift-XRT observations
  82. GRB 240214A: Tiled Swift observations
  83. GRB 240209A: NOT photometry of the AT2024cew / GOTO24pw counterpart candidate
  84. IPN triangulation of GRB 240205A (short)
  85. Fermi-LAT gamma-ray observations of IceCube-240204A
  86. GRB 240205B: PRIME near infrared detection
  87. GRB 240205A (short): Glowbug gamma-ray detection
  88. GRB240204A: Swift/UVOT Upper Limits
  89. Konus-Wind detection of GRB 240205B (long / very soft)
  90. GRB 240205B: VLT/X-shooter redshift
  91. GRB 240205B: REM detection of the optical/NIR afterglow
  92. GRB 240204A : OHP/T193/T120 optical afterglow fading detection
  93. GRB 240205B: Skynet Optical Afterglow Observations
  94. GRB 240205B: Swift detection of a burst
  95. GRB 240204a: Liverpool Telescope optical afterglow detection
  96. GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
  97. GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
  98. GRB 240204A: Montarrenti Observatory optical observations
  99. GRB 240204A: Enhanced Swift-XRT position
  100. GRB 240204A: Mondy optical afterglow 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