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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"

19593 results found.

  1. IceCube-200926B: No neutrino counterpart candidates in ANTARES search
  2. Swift-XRT observations of IceCube 200926A
  3. Fermi-LAT Gamma-ray Observations of IceCube-200926A
  4. GRB 200925B NUTTelA-TAO / BSTI Early Measurements (Preliminary)
  5. GRB 200925B: Swift/UVOT Detection
  6. GRB 200922A: Chilescope optical observations
  7. GRB 200925B: Enhanced Swift-XRT position
  8. GRB 200925B: OSN Afterglow Candidate Discovery
  9. GRB 200925B: Swift detection of a burst
  10. Fermi GRB 200925A: Global MASTER-Net observations report
  11. GRB 200922A: Swift/UVOT Detection
  12. Fermi-LAT Gamma-ray Observations of IceCube-200921A and detection of a new gamma-ray source, Fermi J1256.9+2630
  13. IceCube-200921A: no significant detection in HAWC observations
  14. GRB 200922A: LCO observations
  15. GRB 200917A: Swift/UVOT Upper Limits
  16. GRB 200922A: Enhanced Swift-XRT position
  17. GRB 200922A: Swift detection of a burst with possible optical counterpart
  18. IceCube-200921A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  19. GRB 200914A: Swift-XRT further observations
  20. Fermi GRB 200919C: Global MASTER-Net observations report
  21. GRB 200919A: CrAO/ZTSh early optical upper limit
  22. GRB 200917A: GROWTH-India Telescope optical upper limit.
  23. Swift-XRT observations of IceCube 200916A
  24. IceCube-200916A: No significant detection in HAWC
  25. IceCube-200916A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  26. IPN triangulation of GRB 200916B (short)
  27. Fermi-LAT Gamma-ray Observations of IceCube-200916A
  28. GRB 200917A: Enhanced Swift-XRT position
  29. GRB 200917A: Swift detection of a burst
  30. Swift-XRT observations of IceCube 200911A
  31. IceCube-200911A: No significant detection in HAWC
  32. Fermi-LAT Gamma-ray Observations of IceCube-200911A and detection of a new gamma-ray source, Fermi J0330.1+3743
  33. GRB 200914A: Swift ToO observations
  34. IceCube-200911A: No neutrino counterpart candidates in ANTARES search
  35. IceCube-200911A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  36. IPN triangulation of GRB 200907A (short)
  37. GRB 200829A: T100 observations
  38. GRB 200907B: Swift/UVOT Upper Limits
  39. Fermi GRB 200908A: Global MASTER-Net observations report
  40. GRB 200908A: Fermi GBM Final Real-time Localization
  41. GRB 200907B: MITSuME Okayama optical upper limits
  42. Swift GRB 200907B: Global MASTER-Net observations report
  43. GRB 200907B: Enhanced Swift-XRT position
  44. Correction to GCN 28387: GRB 200907B GROWTH-India optical upper limit
  45. GRB200907A: GROWTH-India optical upper limit
  46. GRB 200907B: Swift detection of a short burst
  47. GRB 200906A: EMIR/GTC NIR upper limit
  48. GRB 200906A: Swift/UVOT Upper Limits
  49. GRB 200906A: GROWTH-India Telescope (GIT) optical r band upper limit
  50. GRB 200906A: Enhanced Swift-XRT position
  51. GRB 200906A: Nanshan/NEXT optical upper limit
  52. GRB 200906A: Swift detection of a burst
  53. GRB 200829A: optical observations, a light curve in R-filter
  54. INTEGRAL Weak#8699: AROMA-N Optical Observation
  55. GRB 200901A: Swift-BAT refined analysis
  56. GRB 200901B: Swift/UVOT Detection
  57. GRB 200901A: Swift/UVOT Detection
  58. GRB 200901A: Swift-XRT refined Analysis
  59. GRB 200901B: Enhanced Swift-XRT position
  60. GRB 200901B: Swift detection of a burst
  61. GRB 200901A: Swift-XRT observations
  62. GRB 200901A: Swift detection of a burst
  63. GRB 200829A: Koshka Zeiss-1000 optical observations
  64. GRB 200829A: Liverpool Telescope observations
  65. GRB 200829A: Kitab optical upper limit
  66. GRB 200829A: further SAO RAS optical observations
  67. GRB 200829A: Nanshan/NEXT optical observations
  68. GRB 200829A: SAO RAS optical observations
  69. GRB 200829A: Global MASTER-Net OT detection
  70. GRB 200829A: Enhanced Swift-XRT position
  71. GRB 200826A: Lowell Discovery Telescope observations of ZTF20abwysqy
  72. GRB 200829A: Swift/UVOT Detection
  73. GRB 200829A: Swift detection of a burst with an optical afterglow
  74. GRB 200826A: Kitab optical observations
  75. Zwicky Transient Facility discovery of ZTF20abtxwfx/AT2020sev, a fast optical transient and candidate afterglow
  76. GRB 200826A: Swift-XRT afterglow detection
  77. GRB 200826A: Tiled Swift observations
  78. GRB 200819A: Swift/UVOT Upper Limits
  79. IceCube-200806A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  80. Swift Trigger 992444: a possible GRB 200821A
  81. IPN triangulation of GRB 200815A (short)
  82. GRB 200819A: Optical Observations from HCT
  83. GRB 200819A: MITSuME Ishigaki optical upper limits
  84. GRB 200729A: Lowell Discovery Telescope observations
  85. GRB 200819A: MITSuME Akeno optical upper limits
  86. GRB 200819A: Kitab, TSHAO optical upper limit
  87. GRB 200819A: Enhanced Swift-XRT position
  88. GRB 200819A: Swift detection of a burst
  89. Swift trigger 990358 is not an astrophysical source
  90. Swift trigger 989458 is likely not an astrophysical source
  91. Alert from the HAWC Burst Monitor HAWC-200814A
  92. IceCube200806A: No significant detection in HAWC
  93. GRB 200809B: Swift-XRT afterglow detection
  94. GRB 200809B: MAXI/GSC detection
  95. GRB 200809B: Swift ToO observations
  96. GRB 200808A: Fermi GBM Final Real-time Localization
  97. GRB 200806A: Nanshan/NEXT optical upper limit
  98. GRB 200806A: VIRT optical observations
  99. GRB 200806A: Swift/UVOT Possible Detection
  100. GRB 200806A: AbAO optical upper limit

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