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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"

3140 results found.

  1. LIGO/Virgo S190720a: No counterpart candidates in KAIT observations
  2. GRB 190720A: Fermi GBM detection
  3. GRB 190720A: BALROG localization (Fermi Trigger 585326534 / GRB 190720613)
  4. GRB 190720A: Fermi GBM Final Real-time Localization
  5. LIGO/Virgo S190718y: No counterpart candidates in CNEOST
  6. LIGO/Virgo S190720a Global MASTER-Net observations report
  7. LIGO/Virgo S190718y: No counterpart candidates in KAIT observations
  8. GRB 190719A: Fermi GBM Final Real-time Localization
  9. Swift GRB190718.2 Global MASTER-Net observations report
  10. GRB 190718A: Swift detection of a burst
  11. Fermi trigger No 585007213 Global MASTER-Net observations report
  12. Fermi trigger No 584977168 Global MASTER-Net observations report
  13. Fermi trigger No 584804684 Global MASTER-Net observations report
  14. GRB 190706C: Insight-HXMT/HE detection
  15. IceCube Alert 190712.05 Global MASTER-Net observations report
  16. Fermi trigger No 584590606 Global MASTER-Net observations report
  17. Fermi trigger No 584583925 Global MASTER-Net observations report
  18. Konus-Wind observation of GRB 190706C
  19. GRB 190706C: CALET Gamma-Ray Burst Monitor detection
  20. GRB 190708B: MAXI/GSC detection
  21. IPN triangulation of GRB 190706D (short)
  22. IPN triangulation of GRB 190706C (long/very bright)
  23. LIGO/Virgo S190706ai: No counterpart candidates in KAIT observations
  24. IPN triangulation of GRB 190704A (short)
  25. GRB 190706B: Swift detection of a burst
  26. Fermi trigger No 583854113 Global MASTER-Net observations report
  27. LIGO/Virgo S190630ag: no counterpart candidate in the SVOM/GWAC observations
  28. LIGO/Virgo S190701ah: Coverage and upper limits from MAXI/GSC observations
  29. GRB 190630B: Tien Shan and Koshka Zeiss-1000 optical upper limits
  30. GRB 190630C: ISON-Castelgrande optical upper limit
  31. LIGO/Virgo S190630ag: No counterpart candidates in AGILE-GRID observations
  32. GRB 190701A: MAXI/GSC detection
  33. Fermi trigger No 583567803 Global MASTER-Net observations report
  34. GRB 190627A: Koshka Zeiss-1000 optical counterpart observations
  35. GRB 190627A: Optical imaging and spectroscopy from Calar Alto
  36. Fermi trigger No 583327924 Global MASTER-Net observations report
  37. Fermi trigger No 583221986 Global MASTER-Net observations report
  38. Fermi trigger No 583111521 Global MASTER-Net observations report
  39. Swift GRB190624.86 Global MASTER-Net observations report
  40. Swift trigger 911102: D50 optical limit
  41. Fermi trigger No 582856902 Global MASTER-Net observations report
  42. GRB 190615B: AstroSat CZTI detection
  43. Fermi trigger No 582615488 Global MASTER-Net observations report
  44. Fermi trigger No 582615488 Global MASTER-Net observations report
  45. Fermi trigger No 582596766 Global MASTER-Net observations report
  46. GRB 190615B: Insight-HXMT/HE detection
  47. Fermi trigger No 582115625 Global MASTER-Net observations report
  48. Fermi trigger No 581986074 Global MASTER-Net observations report
  49. GRB 190604A: Insight-HXMT/HE detection
  50. Fermi trigger No 581469752 Global MASTER-Net observations report
  51. GRB 190604A: AstroSat CZTI detection
  52. GRB190604A: BALROG localization (Fermi Trigger 581337762 / GRB 190604446)
  53. GRB 190604A: Fermi GBM Final Real-time Localization
  54. Fermi Fermi trigger No 581002688 Global MASTER-Net observations report
  55. LIGO/Virgo S190521r: CNEOST follow-up observations
  56. LIGO/Virgo S190521g: No optical counterpart from SVOM/GWAC observations.
  57. LIGO/Virgo S190512at: SVOM/GWAC-F60A observations
  58. LIGO/Virgo S190519bj: MAXI/GSC Observations
  59. LIGO/Virgo S190519bj Global MASTER-Net observations report
  60. Fermi GRB190517.81 Global MASTER-Net observations report
  61. LIGO/Virgo S190517h Global MASTER-Net observations report
  62. LIGO/Virgo S190517h: IceCube Neutrino Search
  63. Fermi GRB190514.67 Global MASTER-Net observations report
  64. LIGO/Virgo S190513bm: Lick/KAIT Follow-Up Observations
  65. LIGO/Virgo S190513bm: Insight-HXMT/HE observation
  66. LIGO/Virgo S190510g: Further KMTNet observation of DECam-GROWTH and DESGW candidates
  67. LIGO/Virgo S190513bm Global MASTER-Net observations report
  68. LIGO/Virgo S190510g: Pan-STARRS and ATLAS observations and candidates
  69. LIGO/Virgo S190512at Global MASTER-Net observations report
  70. Fermi GRB190512.61 Global MASTER-Net observations report
  71. IPN triangulation of GRB 190510A (short)
  72. LIGO/Virgo S190510g: Update on candidate significance
  73. LIGO/Virgo S190510g: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  74. LIGO/Virgo S190510g: Dabancheng/HMT Follow-Up Observations
  75. LIGO/Virgo S190510g: Xinglong/Schmidt Follow-Up Observations
  76. LIGO/Virgo S190510g: SOAR/Goodman follow-up observations
  77. LIGO/Virgo S190510g: CNEOST Follow-Up Observations
  78. LIGO/Virgo S190510g: Lick/KAIT Follow-Up Observations
  79. LIGO/Virgo S190510g: Lulin Optical Follow-up Observations
  80. LIGO/Virgo S190510g Global MASTER-Net observations report
  81. LIGO/Virgo S190503bf: TAROT-GRANDMA observation report
  82. Fermi GRB190507.27 Global MASTER-Net observations report
  83. IceCube-190504A: MASTER optical monitoring analysis
  84. Fermi GRB190505.05 Global MASTER-Net observations report
  85. Fermi GRB190504.68 Global MASTER-Net observations report
  86. LIGO/Virgo S190503bf Global MASTER-Net observations report
  87. IceCube-190503A: Lick/KAIT Follow-Up Observations
  88. Fermi GRB190429.74 Global MASTER-Net observations report
  89. LIGO/Virgo S190426c: YAHPT Optical Observation
  90. LIGO/Virgo S190425z: MASTER detection of the faint flare in SDSS Seyfert galaxy z = 0.09
  91. LIGO/Virgo S190425z: SVOM/GWAC-F60A observations
  92. LIGO/Virgo S190425z: GROWTH-India observations of the Swift/UVOT transient
  93. LIGO/Virgo S190426c: RATIR Optical and NIR Observations of Galaxies
  94. LIGO/Virgo S190426c: COATLI Optical Observations of Galaxies
  95. LIGO/Virgo S190426c: MMT Follow-Up Observations
  96. LIGO/Virgo S190426c: Lick/KAIT Follow-Up Observations
  97. LIGO/Virgo S190426c: CNEOST Optical Observations
  98. LIGO/Virgo S190425z: CNEOST Optical Observations
  99. LIGO/Virgo S190425z: BOOTES-5/JGT observations of galaxies
  100. LIGO/Virgo S190425z: GRANDMA follow-up observations with Les Makes-T60, AZT-8 and Abastumani-T70

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