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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

32548 results found.

  1. GRB 221009A/Swift J1913.1+1946: Lick/Nickel telescope optical observations
  2. Konus-Wind detection of GRB 221009A
  3. GRB 221009A: Lulin SLT-40cm optical observations
  4. Swift J1913.1+1946: New Photometry
  5. GRB 221009A: Upper limits from a neutrino search with IceCube
  6. GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
  7. GRB221009A/Swift J1913.1+1946: SRG/ART-XC observation
  8. GRB 221009A / Swift J1913.1+1946: GIT detection of the optical afterglow
  9. GRB221009A/Swift J1913.1+1946: INTEGRAL SPI/ACS observations
  10. ​GRB 221009A: Multi-color detection of the optical
  11. GRB 221009A: Fermi-LAT refined analysis
  12. GRB 221009A (Swift J1913.1+1946): AGILE/GRID detection
  13. GRB 221009: Swift/UVOT Detection
  14. GRB221009A/Swift J1913.1+1946: ATA follow-up observations
  15. GRB 221009A or Swift J1913.1+1946: PRIME near-infrared detection
  16. GRB 221009A: REM optical and NIR detection of the afterglow
  17. GRB 221009A: Swift-XRT refined Analysis
  18. GRB 221009A (Swift J1913.1+1946): AGILE/MCAL detection
  19. Swift J1913.1+1946: Early Optical Photometry
  20. GRB 221009A: Redshift from X-shooter/VLT
  21. GRB 221009A: Nanshan/NEXT photometry and Xinglong-2.16m spectroscopy
  22. GRB 221009A (Swift J1913.1+1946): MeerLICHT observations
  23. GRB 221009A (Swift J1913.1+1946): Mondy optical observations
  24. Swift J1913.1+1946 : Pre-discovery limits from ZTF
  25. GRB 221009A: Fermi GBM observation
  26. IPN triangulation of extremely bright GRB 221009A
  27. Swift J1913.1+1946: Optical photometry
  28. Swift J1913.1+1946: Liverpool Telescope imaging and spectroscopy
  29. GRB 221009A or Swift J1913.1+1946: Fermi-LAT detection
  30. GRB 221009A: Fermi GBM detection of an extraordinarily bright GRB
  31. GRB 221009A: Swift detected transient may be GRB
  32. GRB 221008A: Swift-XRT observations
  33. GRB 221008A: Tiled Swift observations
  34. GRB 221006A: Swift-XRT observations
  35. GRB 221006A: Tiled Swift observations
  36. GRB 220930A: MITSuME Akeno optical upper limits
  37. GRB 220912A: Detection by VZLUSAT-2
  38. GRB220927A: Detection by GRBAlpha
  39. GRB 220921A: ATCA detection of radio counterpart
  40. GRB 220930A: AbAO Optical Upper Limit
  41. Konus-Wind detection of GRB 220930A
  42. GRB 220930A: AstroSat CZTI detection
  43. GRB 220930A: Swift-BAT refined analysis
  44. GRB 220930A: Swift-XRT refined Analysis
  45. GRB 220930A: LCOGT Optical Upper Limits
  46. GRB 220930A: Swift/UVOT Upper Limits
  47. Swift GRB 220930A: Global MASTER-Net observations report
  48. GRB 220930A: COATLI Upper Limits
  49. Fermi-LAT gamma-ray observations of IceCube-220928A
  50. Konus-Wind detection of GRB 220927A
  51. Fermi GRB 220927A: Global MASTER-Net observations report
  52. IPN triangulation of GRB 220927A (long)
  53. GRB 220921A: LCOGT Optical Observations
  54. GRB 220611A: Host galaxy redshift from VLT/X-shooter
  55. GRB 220924A: Fermi GBM detection
  56. Swift Trigger 1125354 (GRB 220926A) is not a GRB
  57. Swift GRB 220926A: Global MASTER-Net observations report
  58. Analysis of long GRB 220926B detected by INTEGRAL
  59. Fermi GRB 220925A: Global MASTER-Net observations report
  60. GRB 220924A: Swift/BAT-GUANO detection outside the coded FOV
  61. GRB 220921A: ALMA detection
  62. GRB 220921A: DDOTI Detection of the Afterglow
  63. Konus-Wind detection of GRB 220921A
  64. GRB 220921A: Fermi GBM detection
  65. IceCube-220907A: Classification of AT2022oyn as a Type Ia supernova
  66. GRB 220921A: MeerLICHT afterglow observations
  67. GRB 220921A: Swift-XRT Observations
  68. GRB 220921A: MASTER OT inside Fermi-LAT error-box
  69. GRB 220921A: Tiled Swift observations
  70. Fermi-LAT gamma-ray observations of IceCube-220918A and detection of a new gamma-ray source, Fermi J0502.5+0037
  71. IceCube-220918A: Upper limits from a search for additional neutrino events in IceCube
  72. IceCube-220907A: No significant detection in HAWC
  73. GRB 220909A: Fermi GBM observation
  74. Konus-Wind detection of GRB 220910A
  75. Fermi GRB 220912A: Global MASTER-Net observations report
  76. GRB 220910A: Fermi GBM observation
  77. IPN triangulation of GRB 220910A (bright/long)
  78. GRB 220912A: AstroSat CZTI detection
  79. GRB 220831A: DECam optical counterpart follow-up
  80. GRB 220909A: Swift-XRT observations
  81. IPN triangulation of GRB 220905A
  82. GRB 220909A: Swift ToO observations
  83. GRB 220909A: Swift/BAT-GUANO candidate arcminute localization
  84. GRB 220831A: Gemini-South Infrared Observations
  85. GRB 220910A: AstroSat CZTI detection
  86. GRB 220907A: Swift-BAT refined analysis
  87. IceCube-220907A: One Candidate Counterpart from the Zwicky Transient Facility
  88. GRB 220831A: Gemini-South/GMOS detection of potential optical counterpart
  89. IPN triangulation of GRB 220903A (long)
  90. GRB 220907A: Fermi GBM observation
  91. GRB 220907A: Nanshan/NEXT optical upper limits
  92. GRB 220907A: Swift/UVOT Upper Limits
  93. GRB 220907A: Swift-XRT refined Analysis
  94. GRB 220831A: ATCA 5/9 GHz radio observations
  95. Fermi-LAT Gamma-ray Observations of IceCube-220907A
  96. GRB 220907A: Swift-XRT position
  97. GRB 220907A: Swift detection of a burst
  98. GRB 220831A: Swift-UVOT Upper Limits
  99. Fermi GRB 220905A: Global MASTER-Net observations report
  100. Introducing Self-Service Configuration of GCN Notices over Email for Transient Alerts

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