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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"

3105 results found.

  1. GRB 190613B: BALROG localization (Fermi Trigger 582115625 / GRB 190613449)
  2. GRB 190613B: Swift detection of a burst with an optical counterpart
  3. GRB 190613B: Fermi GBM Final Real-time Localization
  4. GRB 190613A: Fermi GBM Final Real-time Localization
  5. GRB 190611B: Fermi GBM detection
  6. Fermi trigger No 581889628 Global MASTER-Net observations report
  7. Fermi trigger No 581882394 Global MASTER-Net observations report
  8. GRB 190609A: Fermi GBM Final Real-time Localization
  9. Fermi trigger No 581719018 Global MASTER-Net observations report
  10. Fermi trigger No 581645543 Global MASTER-Net observations report
  11. Fermi trigger No 581469752 Global MASTER-Net observations report
  12. GRB 190605A: Fermi GBM Final Real-time Localization
  13. Fermi trigger No 581281470 Global MASTER-Net observations report
  14. Konus-Wind observation of extremely bright GRB 190530A
  15. GRB 190525A: AstroSat CZTI detection
  16. LIGO/Virgo S190521r: CNEOST follow-up observations
  17. Fermi GRB190525.03 Global MASTER-Net observations report
  18. GRB 190525A: Fermi GBM Final Real-time Localization
  19. LIGO/Virgo S190521g: No optical counterpart from SVOM/GWAC observations.
  20. IGO/Virgo S190521g: Coverage and upper limits from MAXI/GSC observations
  21. LIGO/Virgo S190512at: SVOM/GWAC-F60A observations
  22. LIGO/Virgo S190519bj: MAXI/GSC Observations
  23. LIGO/Virgo S190519bj Global MASTER-Net observations report
  24. Fermi GRB190517.81 Global MASTER-Net observations report
  25. LIGO/Virgo S190513bm : TAROT-Calern and TAROT-Chile (TCA/TCH)/GRANDMA observation report.
  26. Fermi GRB190514.67 Global MASTER-Net observations report
  27. LIGO/Virgo S190513bm: Lick/KAIT Follow-Up Observations
  28. LIGO/Virgo S190510g: Further KMTNet observation of DECam-GROWTH and DESGW candidates
  29. LIGO/Virgo S190513bm Global MASTER-Net observations report
  30. LIGO/Virgo S190510g: Pan-STARRS and ATLAS observations and candidates
  31. LIGO/Virgo S190512at Global MASTER-Net observations report
  32. LIGO/Virgo S190510g: DOAO Observation
  33. LIGO/Virgo S190510g: KMTNet observation of DECam-GROWTH and DESGW candidates
  34. LIGO/Virgo S190510g: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  35. LIGO/Virgo S190510g: Dabancheng/HMT Follow-Up Observations
  36. LIGO/Virgo S190510g: Xinglong/Schmidt Follow-Up Observations
  37. LIGO/Virgo S190510g: SOAR/Goodman follow-up observations
  38. LIGO/Virgo S190510g: CNEOST Follow-Up Observations
  39. LIGO/Virgo S190510g: Lick/KAIT Follow-Up Observations
  40. LIGO/Virgo S190510g: Lulin Optical Follow-up Observations
  41. LIGO/Virgo S190425z: CAHA-GRANDMA Observation of the Swift UVOT Source
  42. Konus-Wind observation of GRB 190501A
  43. LIGO/Virgo S190510g: HSC Y-band follow-up observation
  44. Fermi GRB190510.12 Global MASTER-Net observations report
  45. LIGO/Virgo S190510g Global MASTER-Net observations report
  46. Fermi GRB190507.97 Global MASTER-Net observations report
  47. Fermi GRB190507.27 Global MASTER-Net observations report
  48. IceCube-190504A: MASTER optical monitoring analysis
  49. Fermi GRB190505.05 Global MASTER-Net observations report
  50. Fermi GRB190504.68 Global MASTER-Net observations report
  51. LIGO/Virgo S190503bf Global MASTER-Net observations report
  52. IceCube-190503A: Lick/KAIT Follow-Up Observations
  53. Fermi GRB190429.74 Global MASTER-Net observations report
  54. LIGO/Virgo S190426c: YAHPT Optical Observation
  55. LIGO/Virgo S190426c: MASTER analysys of GRAWITA transients
  56. LIGO/Virgo S190426c: OAJ-GRANDMA observation report
  57. LIGO/Virgo S190426c: DDOTI/OAN Optical Observations
  58. LIGO/Virgo S190426c: COATLI Optical Observations of Galaxies
  59. LIGO/Virgo S190426c: MMT Follow-Up Observations
  60. LIGO/Virgo S190426c: Lick/KAIT Follow-Up Observations
  61. LIGO/Virgo S190426c: CNEOST Optical Observations
  62. LIGO/Virgo S190425z: CNEOST Optical Observations
  63. LIGO/Virgo S190426c: Optical Wide-field Search with the Zwicky Transient Facility
  64. LIGO/Virgo S190425z: BOOTES-5/JGT observations of galaxies
  65. LIGO/Virgo S190425z: GRANDMA follow-up observations with Les Makes-T60, AZT-8 and Abastumani-T70
  66. LIGO/Virgo S190426c: SAO optical observation
  67. LIGO/Virgo S190425z: Further MMT Follow-Up Observations
  68. LIGO/Virgo S190425z: COATLI Observations of Galaxies
  69. LIGO/Virgo S190426c Global MASTER-Net observations report
  70. LIGO/Virgo S190425z: YAHPT Optical Observation
  71. LIGO/Virgo S190425z: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  72. LIGO/Virgo S190425z: KMTNet Observation
  73. LIGO/Virgo S190425z: GRAWITA TNG observations of ZTF19aarzaod
  74. LIGO/Virgo S190425z: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  75. LIGO/Virgo S190425z: ZTF19aarykkb Imaging from Las Cumbres Observatory
  76. LIGO/Virgo S190425z: J-GEM optical follow-up observations with Subaru/FOCAS
  77. LIGO/Virgo S190425z: Candidates from the Zwicky Transient Facility
  78. LIGO/Virgo S190408an: Gaia Photometric Alerts transient candidates
  79. LIGO/Virgo S190425z: MMT Follow-Up Observations
  80. LIGO/Virgo S190425z: Lick/KAIT Follow-Up Observations
  81. LIGO/Virgo S190425z: INTEGRAL SPI-ACS prompt observation
  82. Fermi GRB190425.09 Global MASTER-Net observations report
  83. LIGO/Virgo S190421ar: Lick/KAIT Follow-Up Observations
  84. LIGO/Virgo S190408an: Liverpool Telescope follow-up imaging observations
  85. Swift GRB190422.96 Global MASTER-Net observations report
  86. Fermi GRB190422.67 Global MASTER-Net observations report
  87. LIGO/Virgo S190421ar Global MASTER-Net observations report
  88. LIGO/VIRGO S190421ar: IceCube Neutrino Search
  89. LIGO/Virgo S190408an: INTEGRAL follow-up observations
  90. Fermi GRB190420.98 Global MASTER-Net observations report
  91. LIGO/Virgo S190412m: SVOM/GWAC observations of the initial skymap
  92. Fermi GRB190419.41 Global MASTER-Net observations report
  93. GRB 190406B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 576241792)
  94. GRB 190404C: MITSuME Akeno and Okayama optical upper limits
  95. GRB190404C: GROWTH-India discovery of optical counterpart
  96. GRB 140404B: MAXI/GSC detection
  97. GRB 190330A: MITSuME Akeno and Okayama optical upper limits
  98. GRB 190331A: Fermi GBM detection
  99. MAGIC follow-up of the X-ray flares of LS I +61�303 dete
  100. GRB 190324A: Swift/UVOT Observations

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