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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"

5050 results found.

  1. LIGO/Virgo S190814bv: no counterpart candidates in Thacher imaging
  2. LIGO/Virgo S190814bv: no counterpart candidates in Swope imaging
  3. LIGO/Virgo S190814bv: no counterpart candidates in Nickel/Direct imaging and non-detections of 2019nmd and 2019nme
  4. LIGO/Virgo S190814bv: no counterpart candidates in Keck I MOSFIRE imaging
  5. LIGO/Virgo S190814bv: MeerLICHT coverage second preliminary skymap
  6. LIGO/Virgo S190814bv Global MASTER-Net optical observations
  7. LIGO/Virgo S190814bv : No counterpart candidate in TAROT-GRANDMA observations
  8. LIGO/Virgo S190814bv: GRAWITA TNG imaging of selected galaxies
  9. LIGO/Virgo S190814bv: Liverpool Telescope imaging of selected galaxies
  10. LIGO/Virgo S190814bv: Nordic Optical Telescope imaging of selected galaxies
  11. Fermi trigger No 587392154 Global MASTER-Net observations report
  12. FRB 190806: MASTER optical observation
  13. GRB 190726A: Insight-HXMT/HE detection
  14. GRB 190805B: AstroSat CZTI detection
  15. Fermi trigger No 586788607 Global MASTER-Net observations report
  16. GRB 190806A: Fermi GBM Final Real-time Localization
  17. GRB 190805B: MAXI/GSC detection
  18. GRB 190731A: Swift-XRT afterglow detection
  19. LIGO/Virgo S190728q: ZTF Forced Photometry for PS1 and DECam-GROWTH optical candidates, and a note on DECam Photometry from GCN 25215
  20. LIGO/Virgo S190728q: No counterpart candidates in KAIT observations
  21. GRB 190728A: Fermi GBM Final Real-time Localization
  22. LIGO/Virgo S190727h: No counterpart candidates in KAIT observations
  23. Fermi trigger No 585864875 Global MASTER-Net observations report
  24. GRB 190726A: BALROG localization (Fermi Trigger 585847498 / GRB 190726642)
  25. GRB 190726A: Fermi GBM Final Real-time Localization
  26. GRB 190723A: Insight-HXMT/HE detection
  27. Fermi trigger No 585621841 Global MASTER-Net observations report
  28. GRB 190724A: Fermi GBM Final Real-time Localization
  29. GRB 190723A: Fermi GBM Final Real-time Localization
  30. LIGO/Virgo S190720a: No counterpart candidates in KAIT observations
  31. GRB 190719C: Swift-XRT light-curve fit
  32. LIGO/Virgo S190720a : no neutrino counterpart candidate in ANTARES search
  33. LIGO/Virgo S190718y: No counterpart candidates in CNEOST
  34. LIGO/Virgo S190718y: No counterpart candidates in KAIT observations
  35. GRB 190718A: Swift-XRT refined Analysis
  36. GRB 190718A: Swift detection of a burst
  37. Fermi trigger No 584583925 Global MASTER-Net observations report
  38. IPN triangulation of GRB 190706D (short)
  39. LIGO/Virgo S190706ai: No counterpart candidates in KAIT observations
  40. IPN triangulation of GRB 190704A (short)
  41. LIGO/Virgo S190701ah: GRAWITA VST-ESO PARANAL observations
  42. GRB 190706B: Swift-XRT refined Analysis
  43. IceCube Alert 190704.78 Global MASTER-Net observations report
  44. Baksan Neutrino Observatory Alert 190703.21 Global MASTER-Net observations report
  45. Baksan Neutrino Observatory Alert 190703.56 Global MASTER-Net observations report
  46. LIGO/Virgo S190630ag: no counterpart candidate in the SVOM/GWAC observations
  47. LIGO/Virgo S190701ah: KMTNet Observation
  48. Fermi-LAT Gamma-ray Observations of IceCube-190629A
  49. GRB 190701A: Swift-XRT refined Analysis
  50. GRB 190630C: Swift-XRT refined Analysis
  51. LIGO/Virgo S190701ah: Upper limits from IceCube neutrino searches
  52. LIGO/Virgo S190630ag: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  53. GRB 190630B: Swift-XRT refined Analysis
  54. IceCube-190629A - IceCube observation of a high-energy neutrino candidate event
  55. Fermi trigger No 583327924 Global MASTER-Net observations report
  56. Swift GRB190624.86 Global MASTER-Net observations report
  57. Fermi trigger No 582856902 Global MASTER-Net observations report
  58. Fermi trigger No 582615488 Global MASTER-Net observations report
  59. Konus-Wind observation of GRB 190611B
  60. GRB 190613B: Swift-XRT refined Analysis
  61. IPN Triangulation of GRB 190611B
  62. GRB 190613A: Swift-XRT refined Analysis
  63. GRB 190611A: Swift-XRT refined Analysis
  64. GRB 190612A: Fermi GBM Final Real-time Localization
  65. Fermi trigger No 581882394 Global MASTER-Net observations report
  66. Fermi trigger No 581645543 Global MASTER-Net observations report
  67. GRB 190604B: VLT Afterglow Detection
  68. GRB 190604B: Swift-XRT refined Analysis
  69. S190602aq: MASTER OT detection
  70. GRB 190531B: Swift-XRT afterglow detection
  71. GRB 190530A: Swift-XRT afterglow detection
  72. LIGO/Virgo S190425z: No counterpart candidate in Zadko-GRANDMA observations.
  73. LIGO/Virgo S190521r: CNEOST follow-up observations
  74. LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC-F30 observations.
  75. LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC observations.
  76. LIGO/Virgo S190524q Global MASTER-Net observations report
  77. LIGO/Virgo S190517h : No counterpart candidate in TAROT-GRANDMA observations.
  78. LIGO/Virgo S190512at: SVOM/GWAC-F60A observations
  79. GRB 190519A: CALET Gamma-Ray Burst Monitor detection
  80. GRB 190519A: Swift-XRT refined Analysis
  81. LIGO/Virgo S190519bj Global MASTER-Net observations report
  82. GRB 190519A: Fermi GBM observation
  83. GRB 190519A: Fermi GBM Final Real-time Localization
  84. Fermi GRB190517.81 Global MASTER-Net observations report
  85. LIGO/Virgo S190517h: HAWC follow-up
  86. LIGO/Virgo S190517h Global MASTER-Net observations report
  87. GRB 190515B: Swift-XRT refined Analysis
  88. LIGO/Virgo S190513bm : TAROT-Calern and TAROT-Chile (TCA/TCH)/GRANDMA observation report.
  89. LIGO/Virgo S190513bm: Lick/KAIT Follow-Up Observations
  90. LIGO/Virgo S190510g: Further KMTNet observation of DECam-GROWTH and DESGW candidates
  91. LIGO/Virgo S190513bm Global MASTER-Net observations report
  92. LIGO/Virgo S190510g: Pan-STARRS and ATLAS observations and candidates
  93. LIGO/Virgo S190512at Global MASTER-Net observations report
  94. GRB 190512A: Fermi GBM observation
  95. Fermi GRB190512.61 Global MASTER-Net observations report
  96. GRB 190511A: Swift-XRT refined Analysis
  97. LIGO/Virgo S190510g: KMTNet observation of DECam-GROWTH and DESGW candidates
  98. LIGO/Virgo S190510g: Update on candidate significance
  99. GRB 190511A: Fermi-LAT detection
  100. LIGO/Virgo S190510g: Dabancheng/HMT Follow-Up Observations

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