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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"

28048 results found.

  1. GRB 200826A: Swift-XRT afterglow detection
  2. GRB 200824A: Insight-HXMT/HE detection
  3. GRB 200826A: BALROG localization (Fermi Trigger 620108997 / GRB 200826187)
  4. Swift Trigger 992444 is due to detector noise
  5. GRB 200819A: Swift/UVOT Upper Limits
  6. IceCube-200806A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  7. Swift Trigger 992444: a possible GRB 200821A
  8. GRB 200819A: Swift-BAT refined analysis
  9. GRB 200815A: MASTER optical observations
  10. IPN triangulation of GRB 200815A (short)
  11. GRB 200819A: Optical Observations from HCT
  12. GRB 200819A: Swift-XRT refined Analysis
  13. GRB 200819A: MITSuME Ishigaki optical upper limits
  14. GRB 200729A: Lowell Discovery Telescope observations
  15. GRB 200819A: MITSuME Akeno optical upper limits
  16. GRB 200819A: Kitab, TSHAO optical upper limit
  17. GRB 200819A: Enhanced Swift-XRT position
  18. Swift GRB 200819A: Global MASTER-Net observations report
  19. GRB 200819A: Swift detection of a burst
  20. Swift trigger 990358 is not an astrophysical source
  21. Swift trigger 989458 is likely not an astrophysical source
  22. Alert from the HAWC Burst Monitor HAWC-200814A
  23. IceCube200806A: No significant detection in HAWC
  24. GRB 200811A: BALROG localization (Fermi Trigger 618851447 / GRB 200811632)
  25. GRB 200809B: Fermi GBM detection
  26. Fermi GRB 200809B: Global MASTER-Net observations report
  27. GRB 200809B: Swift-XRT afterglow detection
  28. GRB 200809B: MAXI/GSC detection
  29. GRB 200809B: AstroSat CZTI detection
  30. GRB 200806A: Nanshan/NEXT optical upper limit
  31. GRB 200806A: VIRT optical observations
  32. GRB 200806A: Swift-BAT refined analysis
  33. GRB 200806A: Swift/UVOT Possible Detection
  34. GRB 200806A: Swift-XRT refined Analysis
  35. Fermi-LAT Gamma-ray Observations of IceCube-200806A
  36. GRB 200806A: AbAO optical upper limit
  37. GRB 200806A: AstroSat CZTI detection
  38. GRB 200806A: MITSuME Akeno optical upper limits
  39. GRB 200806A: Enhanced Swift-XRT position
  40. GRB 200806A: Swift detection of a burst
  41. GRB 200803A: Fermi GBM detection
  42. GRB 200803A: Swift-XRT afterglow detection
  43. Fermi GRB 200801B: Global MASTER-Net observations report
  44. AX J1846.4-0258: Swift-BAT refined analysis
  45. Konus-Wind detection of GRB 200729A
  46. GRB 200802A: BALROG localization (Fermi Trigger 618061611 / GRB 200802491)
  47. GRB 200801C: BOOTES-1 and BOOTES-2 optical limits
  48. Swift GRB200801.84: Global MASTER-Net observations report
  49. GRB 200801B: BALROG localization (Fermi Trigger 617988951 / GRB 200801650)
  50. GRB 200801B: Fermi GBM Final Real-time Localization
  51. GRB 200801A: Fermi GBM Final Real-time Localization
  52. GRB 200729A: RT-22 observations at 36.8 GHz
  53. GRB 200729A: Nanshan/NEXT optical upper limit
  54. GRB 200729A: Swift-BAT refined analysis
  55. GRB 200729A: further analysis of the NOT data
  56. GRB 200729A: Swift/UVOT Upper Limits
  57. GRB 200729A: Swift-XRT refined Analysis
  58. Fermi-GBM Sub-Threshold candidate for GRB 200729A
  59. GRB 200729A: IceCube neutrino search
  60. GRB 200729A: Pan-STARRS pre-explosion source detection
  61. GRB 200729A: Spitzer archival source detection
  62. GRB 200729A: TNG NIR upper limits
  63. GRB 200729A: NOT optical upper limits
  64. GRB 200729A: Enhanced Swift-XRT position
  65. GRB200729A: BOOTES-1 optical upper limit
  66. GRB 200729A: Swift detection of a burst
  67. IceCube Alert 200728.35: Global MASTER-Net observations report
  68. Baksan Neutrino Observatory Alert 200726.66: Global MASTER-Net observations report
  69. GRB 200723A: GOTO candidate afterglow and host galaxy
  70. GRB 200723A: BALROG localization (Fermi Trigger 617214929 / GRB 200723691)
  71. GRB 200722A: BALROG localization (Fermi Trigger 617076900 / GRB 200722094)
  72. GRB 200714E: Swift-XRT afterglow detection
  73. GRB 200716C: VIRT optical detection.
  74. GRB 200716C: Insight-HXMT/HE detection
  75. AMON IC_HAWC 170720: No Neutrino Counterpart detected with ANTARES
  76. GRB 200716C: Optical observations from HCT
  77. GRB 200716B: Insight-HXMT/HE detection
  78. GRB 200716C: Swift-BAT refined analysis
  79. GRB 200716C: Fermi GBM detection
  80. GRB 200716C: AGILE/MCAL detection
  81. GRB 200716C: possible host galaxy from the SDSS
  82. GRB 200716C: Swift-XRT refined Analysis
  83. GRB 200716C: Enhanced Swift-XRT position
  84. GRB200716C: BOOTES-1 optical afterglow detection
  85. GRB 200716C: Swift detection of a burst with an optical counterpart
  86. IPN triangulation of GRB 200716A
  87. GRB 200716A: Fermi GBM detection
  88. GRB 200716B: AstroSat CZTI detection
  89. GRB 200716A: AstroSat CZTI detection
  90. GRB 200715A: Swift-XRT afterglow detection
  91. GRB 200716B: BALROG localization (Fermi Trigger 616577673 / GRB 200716316)
  92. GRB 200716A: BALROG localization (Fermi Trigger 616555602 / GRB 200716060)
  93. GRB 200715A : A long GRB detected by INTEGRAL
  94. GRB 200714E: Fermi GBM observation
  95. GRB 200714E: Swift-XRT observations
  96. GRB 200714E: BALROG localization (Fermi Trigger 616444510 / GRB 200714774)
  97. GRB 200713A: Swift-BAT refined analysis
  98. GRB 200711A: Insight-HXMT/HE detection
  99. GRB 200713A: Swift-XRT refined Analysis
  100. GRB 200713A: Enhanced Swift-XRT position

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