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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"

3138 results found.

  1. GRB 200811A: Fermi GBM Final Real-time Localization
  2. GRB 200811A: BALROG localization (Fermi Trigger 618851447 / GRB 200811632)
  3. Fermi GRB 200809B: Global MASTER-Net observations report
  4. Fermi trigger No 618642276: Global MASTER-Net observations report
  5. GRB 200806A: Nanshan/NEXT optical upper limit
  6. GRB 200806A: AbAO optical upper limit
  7. GRB 200803A: AstroSat CZTI detection
  8. LAT GRB200803.15: Global MASTER-Net observations report
  9. Fermi GRB 200803A: Global MASTER-Net observations report
  10. Fermi GRB 200801B: Global MASTER-Net observations report
  11. Fermi GRB 200802A: Global MASTER-Net observations report
  12. Fermi GRB 200801A: Global MASTER-Net observations report
  13. GRB 200723A: GOTO candidate afterglow and host galaxy
  14. Fermi GRB 200723A: Global MASTER-Net observations report
  15. Konus-Wind observation of GRB 200716C: correction to GCN 28147
  16. Konus-Wind observation of GRB 200716C
  17. Fermi GRB 200714D: Global MASTER-Net observations report
  18. Fermi GRB 200714A: Global MASTER-Net observations report
  19. GRB 200714E: Fermi GBM Final Real-time Localization
  20. GRB 200713A: Swift detection of a burst
  21. HAWC-200907A: No Neutrino Counterpart detected with ANTARES
  22. GRB 200703B: AstroSat CZTI detection
  23. GRB 200702A: Fermi GBM Final Real-time Localization
  24. GRB 200630A: Fermi GBM detection
  25. GRB 200629A: AstroSat CZTI detection
  26. Fermi trigger No 614103490: Global MASTER-Net observations report
  27. Baksan Neutrino Observatory Alert 200617.47: Global MASTER-Net observations report
  28. Fermi GRB 200615A: Global MASTER-Net observations report
  29. Baksan Neutrino Observatory Alert 200614.34: Global MASTER-Net observations report
  30. Fermi GRB 200613A: Global MASTER-Net observations report
  31. Fermi GRB 200607A: Global MASTER-Net observations report
  32. IPN triangulation of GRB 200605A (short)
  33. GRB 200605A: Fermi GBM Final Real-time Localization
  34. Baksan Neutrino Observatory Alert 200603.12: Global MASTER-Net observations report
  35. Fermi GRB 200531A: Global MASTER-Net observations report
  36. GRB 200528A: 1.3m DFOT Optical Upper Limits
  37. IceCube Alert 200523.10: Global MASTER-Net observations report
  38. Fermi GRB 200522B: Global MASTER-Net observations report
  39. GRB 200522A: Swift detection of a short burst
  40. Fermi trigger No 611676654: Global MASTER-Net observations report
  41. GRB 200519A: Swift-XRT refined Analysis
  42. Fermi trigger No 611605955: Global MASTER-Net observations report
  43. Fermi trigger No 611434353: Global MASTER-Net observations report
  44. GRB 200514A: MITSuME Akeno optical upper limits
  45. GRB 200514A: MAXI/GSC detection
  46. GRB 200509C: Fermi GBM Final Real-time Localization
  47. GRB 200506B: Fermi GBM Final Real-time Localization
  48. GRB 200424A: Swift-XRT afterglow detection
  49. SGR 1935+2154: MASTER optical observations
  50. SGR 1935+2154 the Insight-HXMT observation plan
  51. GRB 200424A: Swift-XRT observations
  52. Konus-Wind observation of GRB 200422A
  53. Fermi GRB 200423A: Global MASTER-Net observations report
  54. Fermi GRB 200421A: Global MASTER-Net observations report
  55. Fermi GRB 200420A: Global MASTER-Net observations report
  56. GRB 200412B: AbAO optical observations
  57. IceCube Alert 200410.97: Global MASTER-Net observations report
  58. Baksan Neutrino Observatory Alert 200409.81: Global MASTER-Net observations report
  59. LIGO/Virgo S200224ca: Swift XRT observations, 8 X-ray sources
  60. Baksan Neutrino Observatory Alert 200409.23: Global MASTER-Net observations report
  61. Fermi GRB 200407A: Global MASTER-Net observations report
  62. Fermi GRB 200407B: Global MASTER-Net observations report
  63. IPN triangulation of GRB 200407A (short)
  64. Fermi GRB 200403B: Global MASTER-Net observations report
  65. Fermi GRB 200402C: Global MASTER-Net observations report
  66. Fermi GRB 200401A: Global MASTER-Net observations report
  67. Fermi trigger No 606799116: Global MASTER-Net observations report
  68. GRB 200324A: AROMA-N Optical Observation
  69. GRB 200324A:MITSuME Akeno optical upper limits
  70. GRB 200324A: Swift detection of a burst
  71. Fermi trigger No 606681997: Global MASTER-Net observations report
  72. GRB 200320A: Fermi GBM Final Localization
  73. Fermi trigger No 606263732: Global MASTER-Net observations report
  74. LIGO/Virgo S200316bj : No significant candidates in TAROT - FRAM - GRANDMA observations.
  75. Fermi trigger No 606098435: Global MASTER-Net observations report
  76. IPN triangulation of GRB 200311A
  77. Fermi trigger No 605756501: Global MASTER-Net observations report
  78. Fermi trigger No 605632577: Global MASTER-Net observations report
  79. GRB 200311A: Fermi GBM Final Real-time Localization
  80. GRB 200306C: Swift-BAT refined analysis
  81. Swift GRB200306.95: Global MASTER-Net observations report
  82. Swift GRB200306.95: Global MASTER-Net OT detection
  83. LIGO/Virgo S200302c : No significant candidates in FRAM - TAROT - GRANDMA observations.
  84. LIGO/Virgo S200302c: No counterpart candidates in KAIT observations
  85. LIGO/Virgo S200224ca: Transient found in Swift/UVOT counterpart search
  86. LIGO/Virgo S200302c: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  87. LIGO/Virgo S200225q : No significant candidates in TAROT - FRAM - GRANDMA observations.
  88. GRB 200228B: LCO Optical Upper Limit
  89. LIGO/Virgo S200224ca : No significant candidates in TAROT - FRAM - GRANDMA observations
  90. LIGO/Virgo S200225q: no counterpart candidate in SVOM/GWAC observations
  91. LIGO/Virgo S200224ca: No Counterparts in DDOTI/OAN Optical Observations
  92. Fermi trigger No 604231129: Global MASTER-Net observations report
  93. GRB 200224A: BOOTES-1 and 1.5m OSN optical observations
  94. Swift GRB200224.14: Global MASTER-Net observations report
  95. LIGO/Virgo S200219ac: no counterpart candidate in SVOM/GWAC-F30 observations
  96. LIGO/Virgo S200219ac: no counterpart candidate in SVOM/GWAC observations
  97. LIGO/Virgo S200219ac : No significant candidates in TAROT - FRAM - GRANDMA observations.
  98. LIGO/Virgo S200219ac: No counterpart candidates in KAIT observations
  99. LIGO/Virgo S200213t: AT2020clw/ZTF20aanaoyz, AT2020crd/ZTF20aanakge and AT2020cly/ZTF20aanakes 10.4m GTC spectroscopy
  100. LIGO/Virgo S200219ac: Coverage and upper limits from MAXI/GSC observations

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