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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"

27302 results found.

  1. LIGO/Virgo S190510g: Lick/KAIT Follow-Up Observations
  2. LIGO/Virgo S190510g: Lulin Optical Follow-up Observations
  3. LIGO/Virgo S190510g: Fermi-LAT search for a high-energy gamma-ray counterpart
  4. LIGO/Virgo S190510g: GRAWITA REM optical observations
  5. LIGO/Virgo S190510g: Swift/BAT Counterpart Search
  6. LIGO/Virgo S190510g: CLU/NED Galaxies in the Localization Volume
  7. Konus-Wind observation of GRB 190501A
  8. LIGO/Virgo S190510g: Insight-HXMT/HE observation
  9. GRB 190510A: Fermi GBM Final Real-time Localization
  10. LIGO/Virgo S190510g: MAXI/GSC Observations
  11. S190510g: INTEGRAL inactive at the time of the event
  12. LIGO/Virgo S190510g: Public DECam Observations
  13. LIGO/Virgo S190510g: HAWC follow-up
  14. Fermi GRB190510.12 Global MASTER-Net observations report
  15. LIGO/Virgo S190510g: Fermi GBM Observations
  16. LIGO/Virgo S190510g Global MASTER-Net observations report
  17. GRB 190508A: GOTO optical search - no counterparts
  18. LIGO/Virgo S190503bf: TAROT-GRANDMA observation report
  19. GRB 190508B: Fermi GBM Final Real-time Localization
  20. Fermi GRB190508.81 Global MASTER-Net observations report
  21. GRB 190508A: Fermi GBM Final Real-time Localization
  22. Fermi GRB190507.71 Global MASTER-Net observations report
  23. GRB 190507B: GOTO optical counterpart search
  24. Fermi GRB190508.11 Global MASTER-Net observations report
  25. Fermi GRB190507.97 Global MASTER-Net observations report
  26. GRB 190507B: Fermi GBM Final Real-time Localization
  27. Fermi GRB190507.27 Global MASTER-Net observations report
  28. GRB 190501A: Swift XRT and UVOT Observations
  29. IceCube-190504A: MASTER optical monitoring analysis
  30. LIGO/Virgo S190503bf: AstroSat CZTI upper limits
  31. Fermi Trigger 578903308 / GRB 190507270 / GRB190507A: BALROG localization
  32. GRB 190507A: Fermi GBM Final Real-time Localization
  33. Fermi GRB190506.58 Global MASTER-Net observations report
  34. Update to the Fermi GBM GCN Reporting
  35. IceCube-190504A: Insight-HXMT/HE observation
  36. GRB 190501A: CALET Gamma-Ray Burst Monitor detection
  37. LIGO/Virgo S190503bf: CALET Observations
  38. Fermi GRB190505.82 Global MASTER-Net observations report
  39. IceCube-190503A: Insight-HXMT/HE observation
  40. Fermi GRB190505.05 Global MASTER-Net observations report
  41. Fermi GRB190504.68 Global MASTER-Net observations report
  42. LIGO/Virgo S190503bf Global MASTER-Net observations report
  43. IceCube-190504A: MASTER optical follow-up observations
  44. IceCube-190503A: Lick/KAIT Follow-Up Observations
  45. IPN triangulation of GRB 190504A (short)
  46. LIGO/Virgo S190503bf: Swift/BAT Counterpart Search
  47. LIGO/Virgo S190503bf: Fermi-LAT search for a high-energy gamma-ray counterpart
  48. LIGO/Virgo S190503bf: Insight-HXMT/HE observation
  49. IceCube-190503A: Insight-HXMT/HE observation
  50. LIGO/Virgo S190503bf: Fermi-GBM Observations
  51. Fermi-GBM Observations of IceCube-190503A
  52. LIGO/Virgo S190503bf: MAXI/GSC Observations
  53. LIGO/Virgo S190425z: Insight-HXMT observation and counterpart search
  54. Fermi Trigger 578462495 / GRB 190502168 / GRB190502A: BALROG localization
  55. Fermi GRB190501.79 Global MASTER-Net observations report
  56. LIGO/Virgo S190425z: ZTF pre-detections of Gaia19bpt AT2019ehz
  57. LIGO/Virgo S190425z: 1.3-m optical imaging of UVOT transient field
  58. Fermi GRB190429.74 Global MASTER-Net observations report
  59. LIGO/Virgo S190426c: Fermi-LAT search for a high-energy gamma-ray counterpart
  60. GRB 190427A: CALET Gamma-Ray Burst Monitor detection
  61. LIGO/Virgo S190425z: MASTER detection of the faint flare in SDSS Seyfert galaxy z = 0.09
  62. LIGO/Virgo S190425z: RATIR non-detection of the Swift/UVOT source
  63. GRB 190427A: Swift/UVOT Upper Limits
  64. Fermi Trigger 578170097 / GRB 190428783 / GRB190428A: BALROG localization
  65. LIGO/Virgo S190426c: Additional Candidates from the Zwicky Transient Facility
  66. GRB 190427A, Swift-BAT refined analysis
  67. LIGO/Virgo S190426c: OAJ-GRANDMA observation report
  68. LIGO/Virgo S190425z: MASTER explanation of the nature of an optical flash detected by a Swift as a short flare on a fast-moving WISE brown
  69. LIGO/Virgo S190425z: No i-band detection of the Swift/UVOT transient in SkyMapper observations
  70. LIGO/Virgo S190425z: Spectroscopic observations of two ZTF candidates with SOAR
  71. LIGO/Virgo S190425z: NOT photometry of ZTF19aasckkq
  72. LIGO/Virgo S190425z: SVOM/GWAC-F60A observations
  73. LIGO/Virgo S190425z: Additional Candidates from the Zwicky Transient Facility
  74. LIGO/Virgo S190425z: Swift/UVOT and XRT pre-images at the position of the potential Swift/UVOT counterpart
  75. Fermi GRB190427.19 Global MASTER-Net observations report
  76. GRB 190427A: Fermi GBM detection
  77. LIGO/Virgo S190426c: Lick/KAIT Follow-Up Observations
  78. GRB 190427A: COATLI Optical Observations
  79. LIGO/Virgo S190426c: Optical Wide-field Search with the Zwicky Transient Facility
  80. GRB 190427A: RATIR Optical and NIR Observations
  81. LIGO/Virgo S190426c: Insight-HXMT/HE observation
  82. LIGO/Virgo S190426c: CALET Observations
  83. LIGO/Virgo S190425z: Lulin Observations of Counterpart Search
  84. LIGO/Virgo S190426c: Swift-XRT sources
  85. GRB 190427A: BOOTES-1 and BOOTES-5/JGT early follow-up observations
  86. LIGO/Virgo S190425z - ePESSTO+ spectrum of candidate PS19qu
  87. LIGO/Virgo S190426c: Red and blue transients identified with DECam
  88. LIGO/Virgo S190425z: Fermi-LAT search for a high-energy gamma-ray counterpart
  89. GRB 190427A: Swift-XRT observations
  90. Swift GRB190427.19 Global MASTER-Net observations report
  91. GRB 190427A: Swift detection of a short burst
  92. LIGO/Virgo S190426c: MAXI/GSC Observations
  93. LIGO/Virgo S190426c: Public DECam Observations
  94. LIGO/Virgo S190425z: GRANDMA follow-up observations with Les Makes-T60, AZT-8 and Abastumani-T70
  95. LIGO/Virgo S190426c: Swift/BAT Counterpart Search
  96. LIGO/Virgo S190426c: Fermi GBM Observations
  97. LIGO/Virgo S190426c: AGILE-GRID Observations
  98. Baksan Neutrino Observatory Alert 190405.62: Global MASTER-Net:LIGO/Virgo S190425z: PanSTARR OT AT2019ebq/PS19qp
  99. LIGO/Virgo S190425z: Pierre Auger Observatory follow-up
  100. LIGO/Virgo S190426c Global MASTER-Net observations report

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