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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"

19578 results found.

  1. GRB 200922A: Enhanced Swift-XRT position
  2. GRB 200922A: Swift detection of a burst with possible optical counterpart
  3. IceCube-200921A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  4. GRB 200914A: Swift-XRT further observations
  5. Fermi GRB 200919C: Global MASTER-Net observations report
  6. GRB 200919A: CrAO/ZTSh early optical upper limit
  7. GRB 200917A: GROWTH-India Telescope optical upper limit.
  8. Swift-XRT observations of IceCube 200916A
  9. IceCube-200916A: No significant detection in HAWC
  10. IceCube-200916A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  11. IPN triangulation of GRB 200916B (short)
  12. Fermi-LAT Gamma-ray Observations of IceCube-200916A
  13. GRB 200917A: Enhanced Swift-XRT position
  14. GRB 200917A: Swift detection of a burst
  15. Swift-XRT observations of IceCube 200911A
  16. IceCube-200911A: No significant detection in HAWC
  17. Fermi-LAT Gamma-ray Observations of IceCube-200911A and detection of a new gamma-ray source, Fermi J0330.1+3743
  18. GRB 200914A: Swift ToO observations
  19. IceCube-200911A: No neutrino counterpart candidates in ANTARES search
  20. IceCube-200911A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  21. IPN triangulation of GRB 200907A (short)
  22. GRB 200829A: T100 observations
  23. GRB 200907B: Swift/UVOT Upper Limits
  24. Fermi GRB 200908A: Global MASTER-Net observations report
  25. GRB 200908A: Fermi GBM Final Real-time Localization
  26. GRB 200907B: MITSuME Okayama optical upper limits
  27. Swift GRB 200907B: Global MASTER-Net observations report
  28. GRB 200907B: Enhanced Swift-XRT position
  29. Correction to GCN 28387: GRB 200907B GROWTH-India optical upper limit
  30. GRB200907A: GROWTH-India optical upper limit
  31. GRB 200907B: Swift detection of a short burst
  32. GRB 200906A: EMIR/GTC NIR upper limit
  33. GRB 200906A: Swift/UVOT Upper Limits
  34. GRB 200906A: GROWTH-India Telescope (GIT) optical r band upper limit
  35. GRB 200906A: Enhanced Swift-XRT position
  36. GRB 200906A: Nanshan/NEXT optical upper limit
  37. GRB 200906A: Swift detection of a burst
  38. GRB 200829A: optical observations, a light curve in R-filter
  39. INTEGRAL Weak#8699: AROMA-N Optical Observation
  40. GRB 200901A: Swift-BAT refined analysis
  41. GRB 200901B: Swift/UVOT Detection
  42. GRB 200901A: Swift/UVOT Detection
  43. GRB 200901A: Swift-XRT refined Analysis
  44. GRB 200901B: Enhanced Swift-XRT position
  45. GRB 200901B: Swift detection of a burst
  46. GRB 200901A: Swift-XRT observations
  47. GRB 200901A: Swift detection of a burst
  48. GRB 200829A: Koshka Zeiss-1000 optical observations
  49. GRB 200829A: Liverpool Telescope observations
  50. GRB 200829A: Kitab optical upper limit
  51. GRB 200829A: further SAO RAS optical observations
  52. GRB 200829A: Nanshan/NEXT optical observations
  53. GRB 200829A: SAO RAS optical observations
  54. GRB 200829A: Global MASTER-Net OT detection
  55. GRB 200829A: Enhanced Swift-XRT position
  56. GRB 200826A: Lowell Discovery Telescope observations of ZTF20abwysqy
  57. GRB 200829A: Swift/UVOT Detection
  58. GRB 200829A: Swift detection of a burst with an optical afterglow
  59. GRB 200826A: Kitab optical observations
  60. Zwicky Transient Facility discovery of ZTF20abtxwfx/AT2020sev, a fast optical transient and candidate afterglow
  61. GRB 200826A: Swift-XRT afterglow detection
  62. GRB 200826A: Tiled Swift observations
  63. GRB 200819A: Swift/UVOT Upper Limits
  64. IceCube-200806A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  65. Swift Trigger 992444: a possible GRB 200821A
  66. IPN triangulation of GRB 200815A (short)
  67. GRB 200819A: Optical Observations from HCT
  68. GRB 200819A: MITSuME Ishigaki optical upper limits
  69. GRB 200729A: Lowell Discovery Telescope observations
  70. GRB 200819A: MITSuME Akeno optical upper limits
  71. GRB 200819A: Kitab, TSHAO optical upper limit
  72. GRB 200819A: Enhanced Swift-XRT position
  73. GRB 200819A: Swift detection of a burst
  74. Swift trigger 990358 is not an astrophysical source
  75. Swift trigger 989458 is likely not an astrophysical source
  76. Alert from the HAWC Burst Monitor HAWC-200814A
  77. IceCube200806A: No significant detection in HAWC
  78. GRB 200809B: Swift-XRT afterglow detection
  79. GRB 200809B: MAXI/GSC detection
  80. GRB 200809B: Swift ToO observations
  81. GRB 200808A: Fermi GBM Final Real-time Localization
  82. GRB 200806A: Nanshan/NEXT optical upper limit
  83. GRB 200806A: VIRT optical observations
  84. GRB 200806A: Swift/UVOT Possible Detection
  85. GRB 200806A: AbAO optical upper limit
  86. GRB 200806A: MITSuME Akeno optical upper limits
  87. GRB 200806A: Enhanced Swift-XRT position
  88. GRB 200806A: Swift detection of a burst
  89. GRB 200803B: MASTER possibly OT discovery
  90. GRB 200803A: Fermi GBM detection
  91. GRB 200803A: Swift-XRT afterglow detection
  92. GRB 200803A: Tiled Swift observations
  93. AX J1846.4-0258: Swift-BAT refined analysis
  94. GRB 200729A: RT-22 observations at 36.8 GHz
  95. GRB 200729A: Nanshan/NEXT optical upper limit
  96. GRB 200729A: Swift/UVOT Upper Limits
  97. GRB 200729A: TNG NIR upper limits
  98. GRB 200729A: NOT optical upper limits
  99. GRB 200729A: Enhanced Swift-XRT position
  100. GRB 200729A: Swift detection of a burst

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