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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"

11102 results found.

  1. Fermi-LAT Gamma-ray Observations of IceCube-191001A
  2. IceCube-191001A: Not observable by Fermi-GBM
  3. IPN triangulation of GRB 191001A
  4. GRB 191001A: Swift ToO observations
  5. GRB 191001A: KAIT Optical Upper Limit
  6. GRB 191001A: RATIR Optical and NIR Observations
  7. IceCube-191001A - IceCube observation of a high-energy neutrino candidate event
  8. GRB 191001A: DDOTI Optical Counterpart Candidate
  9. LIGO/Virgo S190930t: No counterpart candidates in Fermi-LAT observations
  10. Fermi trigger No 591604915: Global MASTER-Net observations report
  11. LIGO/Virgo S190930s: No counterpart candidates in Fermi-LAT observations
  12. GRB 191001A: BALROG localization (Fermi Trigger 591604915 / GRB 191001279)
  13. GRB 191001A: Fermi GBM Final Real-time Localization
  14. LIGO/Virgo S190930t: Upper limits from Fermi-GBM Observations
  15. LIGO/Virgo S190930s: Upper limits from Fermi-GBM Observations
  16. GRB 190928A: Insight-HXMT/HE detection
  17. Fermi trigger No 591532362: Global MASTER-Net observations report
  18. GRB 190930A: Fermi GBM Final Real-time Localization
  19. IPN triangulation of GRB 190928A (long/bright)
  20. Fermi trigger No 591391412: Global MASTER-Net observations report
  21. Fermi trigger No 591321287: Global MASTER-Net observations report
  22. LIGO/Virgo S190924h: No counterpart candidates in Fermi-LAT observations
  23. LIGO/Virgo S190924h: Upper limits from Fermi-GBM Observations
  24. Fermi-LAT Gamma-ray Observations of IceCube-190922B
  25. LIGO/Virgo S190923y: No counterpart candidates in Fermi-LAT observations
  26. Fermi-LAT Gamma-ray Observations of IceCube-190922A
  27. LIGO/Virgo S190923y: Upper limits from Fermi-GBM Observations
  28. GRB 190923A: BALROG localization (Fermi Trigger 590942887 / GRB 190923617)
  29. GRB 190923A: Fermi GBM Final Real-time Localization
  30. Fermi trigger No 590899086: Global MASTER-Net observations report
  31. IceCube-190922B: Upper limits from Fermi-GBM Observations
  32. IceCube-190922A: Upper limits from Fermi-GBM Observations
  33. IceCube-190922B - IceCube observation of a high-energy neutrino candidate event
  34. IceCube-190922A - IceCube observation of a high-energy neutrino candidate event
  35. Fermi trigger No 590777160: Global MASTER-Net observations report
  36. GRB 190921A: Fermi GBM Final Real-time Localization
  37. GRB 190919B: LCO Optical Afterglow Detection
  38. Fermi trigger No 590621700: Global MASTER-Net observations report
  39. Fermi trigger No 590610007: Global MASTER-Net observations report
  40. GRB 190919A: Fermi GBM Final Real-time Localization
  41. HAWC-190916A: Upper limits from Fermi-GBM Observations
  42. GRB 190828B: AstroSat CZTI detection
  43. Fermi trigger No 590335819: Global MASTER-Net observations report
  44. LIGO/Virgo S190915ak: Upper limits from Fermi-GBM Observations
  45. LIGO/Virgo S190915ak: No counterpart candidates in Fermi-LAT observations
  46. GRB 190916A: Fermi GBM Final Real-time Localization
  47. GRB 190915A: Insight-HXMT/HE detection
  48. GRB190915A: MASTER optical observation of BALROG Fermi GRB localization
  49. GRB 190915A: BALROG localization (Fermi Trigger 590219102 / GRB 190915240)
  50. GRB 190915A: Fermi GBM Final Real-time Localization
  51. GRB 190914A: Fermi GBM Final Real-time Localization
  52. GRB 190828C: AstroSat CZTI detection
  53. Fermi trigger No 590038994: Global MASTER-Net observations report
  54. LIGO/Virgo S190910h: No counterpart candidates in Fermi-LAT observations
  55. GRB 190913A: Fermi GBM Final Real-time Localization
  56. Update to the Fermi GBM Localizations
  57. LIGO/Virgo S190910d: No counterpart candidates in Fermi-LAT observations
  58. LIGO/Virgo S190910h: Upper limits from Fermi-GBM Observations
  59. LIGO/Virgo S190910d: Upper limits from Fermi-GBM Observations
  60. GRB 190910A: Fermi GBM Final Real-time Localization
  61. GRB 190901A: AstroSat CZTI detection
  62. ZTF19abvizsw/AT2019pim, search for GRB in SPI-ACS/INTEGRAL data
  63. Fermi trigger No 589561732 Global MASTER-Net observations report
  64. GRB 190829A observations in CrAO, photometry of the SN
  65. Fermi trigger No 589487114 Global MASTER-Net observations report
  66. GRB 190906B: Fermi GBM Final Real-time Localization
  67. GRB 190829A: GTC confirmation of an associated Type Ic-BL Supernova
  68. GRB 190829A: ATCA cm-band detection
  69. Fermi trigger No 589419513 Global MASTER-Net observations report
  70. GRB 190905A: Fermi GBM Final Real-time Localization
  71. Fermi GBM GCN 25668 Retraction
  72. GRB190829A: Keck LRIS spectroscopic confirmation of the accompanying supernova
  73. IPN triangulation of GRB 190903A (short)
  74. Konus-Wind observation of GRB 190829A
  75. GRB 190829A: MASTER confirmation of GROND SN
  76. GRB 190901A: Insight-HXMT/HE detection
  77. Fermi trigger No 589263065 Global MASTER-Net observations report
  78. Liverpool Telescope observations of ZTF19abvizsw, a candidate untriggered GRB afterglow
  79. GRB 190904A: Fermi GBM Final Real-time Localization
  80. GRB 190829A: LCO Optical Afterglow Detection
  81. Fermi trigger No 589223981 Global MASTER-Net observations report
  82. GRB 190903A: Fermi GBM detection
  83. GRB 190903A: Fermi GBM Final Real-time Localization
  84. LIGO/Virgo S190901ap: No counterpart candidates in Fermi-LAT observations
  85. LIGO/Virgo S190901ap: Upper limits from Fermi-GBM Observations
  86. Fermi GBM trigger 589060361/190901828 is not a GRB
  87. Fermi trigger No 589065714 Global MASTER-Net observations report
  88. GRB 190901A: BALROG localization (Fermi Trigger 589065714 / GRB 190901890)
  89. GRB 190901A: Fermi GBM Final Real-time Localization
  90. Fermi trigger No 589060361 Global MASTER-Net observations report
  91. GRB 190829A: Liverpool Telescope observations
  92. Fermi trigger No 588962322 Global MASTER-Net observations report
  93. GRB 190829A: NOEMA detection of the mm afterglow
  94. Fermi trigger No 588931056 Global MASTER-Net observations report
  95. GRB 190831A: Fermi GBM Final Real-time Localization
  96. GRB 190829A: UKIRT detection of the NIR Afterglow
  97. GRB 190829A: MMT detection of the optical afterglow
  98. GRB 190829A: No Neutrino Counterpart detected with ANTARES
  99. GRB 190829A, Swift-BAT refined analysis
  100. GRB 190829A: AGILE-GRID upper limits

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