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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"

28677 results found.

  1. GRB 200906A: OSN 1.5m Upper Limit
  2. GRB 200906A: Swift-XRT refined Analysis
  3. GRB 200906A: Fermi GBM detection
  4. GRB 200906A: Nanshan/NEXT optical upper limit
  5. Fermi GRB 200904A: Global MASTER-Net observations report
  6. Fermi GRB 200903C: Global MASTER-Net observations report
  7. GRB 200903A: Fermi GBM detection
  8. GRB 200903A: Swift-BAT refined analysis
  9. GRB 200829A: optical observations, a light curve in R-filter
  10. GRB 200903B: Insight-HXMT/HE detection
  11. GRB 200903A: CALET Gamma-Ray Burst Monitor detection
  12. AGILE detection of a burst (AGILE trigger no. 526185273)
  13. ZTF20abtxwfx/AT2020sev : AstroSat CZTI non-detection of a transient
  14. Fermi GRB 200903B: Global MASTER-Net observations report
  15. GRB 200901A: MASTER OT early detection
  16. GRB 200901B: Swift-XRT refined Analysis
  17. GRB 200901B: Swift-BAT refined analysis
  18. GRB 200901A: Swift-BAT refined analysis
  19. GRB 200901B: Swift/UVOT Detection
  20. GRB 200901A: Swift/UVOT Detection
  21. GRB 200901A: Swift-XRT refined Analysis
  22. GRB 200901A: Fermi GBM observation
  23. GRB 200829A: Swift/UVOT-XRT photometric redshift
  24. GRB 200829A: Koshka Zeiss-1000 optical observations
  25. GRB 200829A: Liverpool Telescope observations
  26. GRB 200829A: Continued Nanshan/NEXT optical observations
  27. GRB 200829A: Kitab optical upper limit
  28. GRB 200829A: further SAO RAS optical observations
  29. Fermi GRB 200830A: Global MASTER-Net observations report
  30. GRB 200829A: Fermi GBM detection
  31. GRB 200829A: Swift-BAT refined analysis
  32. GRB 200829A: Nanshan/NEXT optical observations
  33. Konus-Wind detection of GRB 200829A (a clone of GRB 200826B?)
  34. GRB 200829A: SAO RAS optical observations
  35. GRB 200826A
  36. GRB 200829A: Swift-XRT refined Analysis
  37. GRB200829A: optical afterglow detection
  38. GRB 200829A: Global MASTER-Net OT detection
  39. GRB 200829A: AGILE/MCAL detection
  40. GRB 200826A: Lowell Discovery Telescope observations of ZTF20abwysqy
  41. GRB 200829A: Swift/UVOT Detection
  42. Swift GRB 200829A: Global MASTER-Net observations report
  43. GRB 200829A: TSHAO optical observations
  44. GRB 200826A: Kitab optical observations
  45. Zwicky Transient Facility discovery of ZTF20abtxwfx/AT2020sev, a fast optical transient and candidate afterglow
  46. Konus-Wind detection of GRB 200826B
  47. IPN triangulation of GRB 200826B
  48. GRB 200826A: VLA Detection at 6 GHz
  49. GRB 200826A: further analysis of the Konus-Wind data and classification
  50. GRB 200826A: Swift-XRT afterglow detection
  51. GRB 200824A: Insight-HXMT/HE detection
  52. GRB 200826B: Fermi GBM detection
  53. Fermi GRB 200826B: Global MASTER-Net observations report
  54. Fermi GRB 200824A: Global MASTER-Net observations report
  55. GRB200826A: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi Short GRB (Trigger 620108997)
  56. Konus-Wind detection of GRB 200826A
  57. GRB200826A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 620108997)
  58. IPN triangulation of GRB 200826A (short/bright)
  59. GRB 200826A: Tiled Swift observations
  60. GRB 200826A: AGILE detection
  61. GRB 200826A: AstroSat CZTI detection
  62. GRB 200826A: Fermi GBM observation
  63. Fermi GRB 200826A: Global MASTER-Net observations report
  64. Swift Trigger 992444 is due to detector noise
  65. GRB 200819A: Swift/UVOT Upper Limits
  66. IceCube-200806A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  67. Konus-Wind observation of GRB 200815A
  68. GRB 200819A: Swift-BAT refined analysis
  69. GRB 200815A: MASTER optical observations
  70. IPN triangulation of GRB 200815A (short)
  71. GRB 200819A: Optical Observations from HCT
  72. GRB 200819A: Swift-XRT refined Analysis
  73. GRB 200819A: MITSuME Ishigaki optical upper limits
  74. GRB 200729A: Lowell Discovery Telescope observations
  75. GRB 200819A: MITSuME Akeno optical upper limits
  76. GRB 200819A: Kitab, TSHAO optical upper limit
  77. Swift GRB 200819A: Global MASTER-Net observations report
  78. Swift Trigger 990358 is due to detector noise
  79. Swift Trigger 989458 is due to detector noise
  80. Fermi GRB 200817A: Global MASTER-Net observations report
  81. GRB 200815A: CALET Gamma-Ray Burst Monitor detection of a short burst
  82. Alert from the HAWC Burst Monitor HAWC-200814A
  83. IceCube200806A: No significant detection in HAWC
  84. GRB 200809B: Fermi GBM detection
  85. Fermi GRB 200809B: Global MASTER-Net observations report
  86. GRB 200809B: Swift-XRT afterglow detection
  87. GRB 200809B: MAXI/GSC detection
  88. GRB 200809B: Swift ToO observations
  89. GRB 200809B: AstroSat CZTI detection
  90. GRB 200809B: Swift/BAT-GUANO detection and arcminute localization
  91. GRB 200808A: AGILE detection
  92. GRB 200806A: CALET Gamma-Ray Burst Monitor detection
  93. Fermi GRB 200808A: Global MASTER-Net observations report
  94. GRB 200806A: Nanshan/NEXT optical upper limit
  95. IPN triangulation of GRB 200805A (short)
  96. GRB 200806A: CAHA optical afterglow confirmation
  97. GRB 200803A: Chilescope optical upper limit
  98. GRB 200806A: VIRT optical observations
  99. GRB 200806A: Swift-BAT refined analysis
  100. GRB 200806A: Swift/UVOT Possible Detection

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