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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"

19595 results found.

  1. GRB 201020B: Redshift from GTC/OSIRIS
  2. GRB 201024A: Redshift from GTC/OSIRIS
  3. GRB 201024A: Swift detection of a burst with an optical afterglow
  4. IceCube-201021A: No significant detection in HAWC
  5. IceCube-201021A: Optical counterpart of WISEA J172314.13+142101.5
  6. GRB 201020B: GROWTH-India Telescope optical observations
  7. Fermi-LAT Gamma-ray Observations of IceCube-201021A and detection of a new gamma-ray source, Fermi J1725.5+1312
  8. GRB 201020B: Konkoly Obs. optical detection
  9. Swift-XRT observations of IceCube 201021A (2)
  10. GRB 201020A: GROWTH-India Telescope late-time optical upper limit
  11. GRB 201021C: Swift/UVOT Detection
  12. GRB 201020B: Swift/UVOT Detection
  13. GRB 201020A: Swift/UVOT Observations
  14. GRB 201014A: 2.0m HCT upper limit
  15. GRB 201020B: Swift-XRT afterglow detection
  16. GRB 201020A: VIRT optical observations
  17. GRB 201021C: Enhanced Swift-XRT position
  18. GRB 201021C: MASTER optical synchronously observation
  19. IceCube-201021A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  20. GRB 201021C: Swift detection of a burst with an optical counterpart
  21. HAWC-201019A: No Neutrino Counterpart detected with ANTARES
  22. GRB200826A: GMOS-N detection of a supernova bump
  23. GRB 201020B: Mondy optical observations
  24. Swift-XRT observations of IceCube 201021A
  25. GRB 201015A: SAO RAS optical observations
  26. GRB 201020B: Swift ToO observations
  27. GRB 201020B: Nanshan/NEXT optical afterglow confirmation
  28. GRB 201020B: MASTER bright optical afterglow detection
  29. GRB 201020B: Fermi-LAT detection
  30. GRB 201020A: GROWTH-India Telescope optical observations
  31. Alert from the HAWC Burst Monitor HAWC-201019A
  32. GRB 201020A: Swift-BAT refined analysis
  33. GRB 201020A: Nanshan/NEXT optical observations
  34. GRB 201014A: SAO RAS optical observations
  35. GRB 201020A: Enhanced Swift-XRT position
  36. GRB 201020A: MITSuME Akeno optical observation
  37. GRB 201020A: Swift detection of a burst with an optical counterpart.
  38. GRB 201017A iTelescope observation
  39. GRB 201017A: SAO RAS optical observations
  40. GRB 201017A: GROWTH-India optical upper limit
  41. GRB 201017A: MITSuME Akeno optical upper limits
  42. GRB 201015A: GROWTH-India Telescope (GIT) upper limit
  43. GRB 201015A: HCT optical photometric follow-up
  44. GRB 201015A: Xinglong-2.16m optical observations
  45. GRB 201017A: Enhanced Swift-XRT position
  46. GRB 201017A: Swift detection of a burst
  47. GRB 201015A: Swift/UVOT Detection
  48. IceCube-201014A: No significant detection in HAWC
  49. GRB 201014A: Nanshan/NEXT optical observations
  50. GRB 201014A: Lowell Discovery Telescope afterglow imaging
  51. GRB201015A: Nanshan/NEXT early optical observations
  52. GRB 201016A: AstroSat CZTI detection
  53. GRB 201008A: Swift-XRT afterglow detection
  54. GRB 201015A: Enhanced Swift-XRT position
  55. GRB 201014A: Swift/UVOT Upper Limits
  56. GRB 201015A: GOTO confirmation of afterglow detection
  57. GRB 201014A: Swift-XRT refined Analysis
  58. GRB 201015A: NOT optical afterglow confirmation
  59. GRB 201015A: Swift-XRT observations
  60. Swift GRB 201015A: Global MASTER-Net observations report
  61. GRB 201014A (Swift trigger =1000255): CrAO/ZTSH optical afterglow discovery
  62. Swift Trigger 1000255 is probably not a GRB
  63. Fermi-LAT Gamma-ray Observations of IceCube-201014A
  64. GRB 201013A: TSHAO and AbAO optical observations, afterglow confirmation
  65. IceCube-201014A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  66. GRB 201013A: Swift/UVOT Upper Limits
  67. SGR 1830-0645: Swift/UVOT Upper Limits
  68. GRB 201013A: Enhanced Swift-XRT position
  69. GRB 201013A: Swift detection of a burst
  70. GRB 201006A: Chandra upper limit on the X-ray afterglow
  71. SGR 1830-0645 / GRB 201010A: Kitab optical non-detection
  72. GRB 201010A: Enhanced Swift-XRT position
  73. Swift detection of a new SGR 1830-0645 or a short GRB 201010A
  74. IceCube-200929A: JCMT/SCUBA2 observations
  75. IceCube-201007A: No significant detection in HAWC
  76. GRB 201008B: Fermi GBM Final Localization
  77. IceCube-200926A: Upper limits from Insight-HXMT Observations
  78. GRB 201008A: Swift ToO observations
  79. GRB 201008A: Swift/BAT-GUANO detection and possible arcminute localization
  80. Fermi-LAT Gamma-ray Observations of IceCube-201007A
  81. Swift-XRT observations of IceCube 201007A
  82. IceCube-201007A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  83. GRB 201006A: GROWTH-India Telescope optical upper limit
  84. GRB 201006A: Lowell Discovery Telescope upper limits
  85. GRB 201006A: MITSuME Akeno optical upper limits
  86. GRB 201006A: Swift/UVOT Upper Limits
  87. GRB 201006A: Enhanced Swift-XRT position
  88. GRB 201006A: Swift detection of a burst
  89. GRB 201001A: Swift/UVOT Upper Limits
  90. IceCube-200926B: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  91. IceCube-200929A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  92. GRB 201001A: TSHAO optical upper limit
  93. GRB 201001A: Xinglong-2.16m optical upper limit
  94. GRB 201001A: MITSuME Akeno optical upper limits
  95. IceCube-200926A: JCMT/SCUBA2 observations
  96. IceCube-200929A: No significant detection in HAWC
  97. Swift-XRT observations of IceCube 200929A
  98. GRB 201001A: Enhanced Swift-XRT position
  99. GRB 201001A: Swift detection of a burst
  100. Fermi-LAT Gamma-ray Observations of IceCube-200929A

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