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 240204A: Swift detection of a burst
  2. IPN triangulation of GRB 240124B
  3. GRB 240128A: Glowbug gamma-ray detection
  4. GRB 240128A: GRBAlpha detection
  5. GRB 240128A: Tiled Swift observations
  6. GRB 240124B: AstroSat CZTI detection
  7. GRB 240123C: AstroSat CZTI detection
  8. GRB240122A: PRIME near infrared detection
  9. GRB 240123A: Glowbug gamma-ray detection
  10. GRB 240125A (short): Glowbug gamma-ray detection
  11. GRB 240123A: GRBAlpha detection
  12. IPN triangulation of GRB 240123C (short)
  13. Fermi-LAT gamma-ray observations of IceCube-240123A
  14. GRB 240123A: further SAO RAS optical observations
  15. GRB 240123A: SAO RAS optical observations
  16. GRB 240123A : MITSuME Akeno optical afterglow candidate detection
  17. GRB 240123A: Enhanced Swift-XRT position
  18. GRB 240122A: Swift/UVOT Upper Limits
  19. GRB 240123A: Swift-XRT refined Analysis
  20. GRB 240118A: Swift/UVOT Upper Limits
  21. GRB 240122B: Glowbug gamma-ray detection
  22. GRB 240123A: Mondy optical afterglow observations
  23. GRB 240123A: Swift detection of a burst with a possible optical counterpart
  24. GRB 240122A: Swift-XRT afterglow detection
  25. GRB 240122A: Tiled Swift observations
  26. IPN triangulation of GRB 240119A (short)
  27. GRB 240118A: Mondy optical observations
  28. GRB 240118A: Swift-XRT afterglow detection
  29. IceCube-240105A: Detection of NIR flare of PKS 0446+11 with WINTER
  30. GRB 240117A: AstroSat CZTI detection
  31. GRB 240118A: Swift ToO observations
  32. GRB 240118A: AbAO optical upper limit
  33. GRB 240117A: Glowbug gamma-ray detection
  34. LIGO/Virgo/KAGRA S240109a: Upper limits from Swift/BAT-GUANO
  35. GRB 240112D: Glowbug gamma-ray detection
  36. GRB 240112C: Glowbug gamma-ray detection
  37. GRB 240112C: Swift/UVOT Detection
  38. GRB 240112C: Swift-XRT refined Analysis
  39. GRB 240112C: SAO RAS optical observations
  40. GRB 240112C: Swift detection of a burst with an optical counterpart
  41. Fermi-LAT detection of increased gamma-ray activity of blazar PKS 0446+11, located inside the IceCube-240105A error region
  42. GRB 240108A: Glowbug gamma-ray detection
  43. GRB 240106B: Glowbug gamma-ray detection
  44. GRB 240106A: Glowbug gamma-ray detection
  45. GRB 231215A: radio detection with the VLA
  46. GRB 230818A: further radio observations with the VLA
  47. GRB 230812B: further radio observations with the VLA
  48. Swift GRB240109.17: Global MASTER-Net observations report
  49. LIGO/Virgo/KAGRA S240104bl: Upper limits from Swift/BAT-GUANO
  50. IPN triangulation of GRB 240101C (short)
  51. GRB 240101A: 1.3m DFOT optical observations
  52. GRB 240102A: 1.3m DFOT optical upper limit
  53. GRB 240101B: 1.3m DFOT optical upper limit
  54. GRB 240102C: AstroSat CZTI detection
  55. GRB 240102A: Swift-BAT refined analysis
  56. GRB 240102A: Swift/UVOT Upper Limits
  57. GRB 240102A: Enhanced Swift-XRT position
  58. GRB 240102A: Swift-XRT refined Analysis
  59. GRB 240102A: LCOGT Optical Upper Limits
  60. GRB 240101B: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  61. GRB 240102A: Swift detection of a burst
  62. GRB 240101A: Terskol Zeiss-2000 optical observations
  63. GRB 240101B: Swift/UVOT Upper Limits
  64. GRB 240101A: Swift/UVOT Upper Limits
  65. GRB 240101B: Enhanced Swift-XRT position
  66. GRB 240101A: Enhanced Swift-XRT position
  67. GRB 240101B: Swift detection of a burst
  68. GRB 231230A: Swift-XRT refined Analysis
  69. GRB 231230A: Enhanced Swift-XRT position
  70. GRB 231230A: Swift/UVOT Upper Limits
  71. GRB 231230A: NOT optical upper limits
  72. GRB 231230A: Swift detection of a burst
  73. GRB 231210B: BOOTES-7 optical upper limit
  74. LIGO/Virgo/KAGRA S231224e: Upper limits from Swift/BAT-GUANO
  75. GRB 231222B: Swift-XRT afterglow detection
  76. GRB 231222A: Tiled Swift observations
  77. IceCube-231211A: GRANDMA observations of PKS2047+098
  78. GRB 231220A: Swift ToO observations
  79. GRB 231216A: GAD Observatory, La Spezia, Italy upper limit
  80. GRB 231216A: optical upper limits from the INAF Asiago Observatory
  81. GRB 231215A: AMI-LA radio detection
  82. GRB 231216A: Nanshan/HMT optical upper limit
  83. GRB 231216A: LCOGT Optical Upper Limits
  84. GRB 231216A: Osservatorio Astronomico Nastro Verde upper limit
  85. GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
  86. GRB 231216A: Swift-XRT refined Analysis
  87. GRB 231216A: REM NIR upper limits
  88. GRB 231216A: Swift/UVOT Upper Limits
  89. GRB 231216A: R-band observations from T120 at Observatoire de Haute-Provence
  90. GRB 231216A: GIT optical upper limit
  91. GRB 231216A: Swift detection of a burst
  92. GRB 231214A: Swift/UVOT Upper Limits
  93. GRB 231215A: GAD Observatory, La Spezia, Italy upper limit;
  94. GRB 231215A: Fermi GBM observation
  95. GRB 231215A : OHP/T193 optical afterglow detection
  96. GRB 231215A: Swift/UVOT Detection
  97. GRB 231215A: AKO Optical Upper Limit
  98. GRB 231215A: Enhanced Swift-XRT position
  99. GRB 231214A: REM optical/NIR upper limits
  100. GRB 231215A: GROWTH-India optical follow-up

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