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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"

11528 results found.

  1. GRB 190829A: MASTER confirmation of GROND SN
  2. GRB 190901A: Insight-HXMT/HE detection
  3. Fermi trigger No 589263065 Global MASTER-Net observations report
  4. Liverpool Telescope observations of ZTF19abvizsw, a candidate untriggered GRB afterglow
  5. GRB 190904A: Fermi GBM Final Real-time Localization
  6. GRB 190829A: LCO Optical Afterglow Detection
  7. Fermi trigger No 589223981 Global MASTER-Net observations report
  8. GRB 190903A: Fermi GBM detection
  9. GRB 190903A: Fermi GBM Final Real-time Localization
  10. LIGO/Virgo S190901ap: No counterpart candidates in Fermi-LAT observations
  11. LIGO/Virgo S190901ap: Upper limits from Fermi-GBM Observations
  12. Fermi GBM trigger 589060361/190901828 is not a GRB
  13. Fermi trigger No 589065714 Global MASTER-Net observations report
  14. GRB 190901A: BALROG localization (Fermi Trigger 589065714 / GRB 190901890)
  15. GRB 190901A: Fermi GBM Final Real-time Localization
  16. Fermi trigger No 589060361 Global MASTER-Net observations report
  17. GRB 190829A: Liverpool Telescope observations
  18. Fermi trigger No 588962322 Global MASTER-Net observations report
  19. GRB 190829A: NOEMA detection of the mm afterglow
  20. Fermi trigger No 588931056 Global MASTER-Net observations report
  21. GRB 190831A: Fermi GBM Final Real-time Localization
  22. GRB 190829A: UKIRT detection of the NIR Afterglow
  23. GRB 190829A: MMT detection of the optical afterglow
  24. GRB 190829A: No Neutrino Counterpart detected with ANTARES
  25. GRB 190829A, Swift-BAT refined analysis
  26. GRB 190829A: AGILE-GRID upper limits
  27. GRB 190829A: AGILE ratemeters detection and MCAL upper limits
  28. GRB 190829A: Fermi GBM detection
  29. GRB 190829A: Fermi-LAT Upper Limits
  30. GRB 190829A:: Global MASTER-net optical clear and polarization observations scheduler and some spiculations
  31. Fermi trigger No 588838851 Global MASTER-Net observations report
  32. GRB 190829A: 10.4m GTC spectroscopy
  33. GRB 190830B: Fermi GBM Final Real-time Localization
  34. GRB 190830A: Fermi GBM Final Real-time Localization
  35. GRB 190829A: GROWTH India detection of afterglow
  36. Fermi trigger No 588801358 Global MASTER-Net observations report
  37. GRB 190829A: Swift detection of a burst consistent with a galaxy at z=0.08
  38. GRB 190829A: Fermi GBM Final Real-time Localization
  39. GRB 190828B: VLT/X-shooter optical afterglow candidate
  40. LIGO/Virgo S190828l: No counterpart candidates in Fermi-LAT observations
  41. GRB 190828B: Fermi GBM observation
  42. LIGO/Virgo S190828j: No counterpart candidates in Fermi-LAT observations
  43. LIGO/Virgo S190828l: Upper limits from Fermi-GBM Observations
  44. LIGO/Virgo S190828j: Upper limits from Fermi-GBM Observations
  45. GRB 190828C: BALROG localization (Fermi Trigger 588696271 / GRB 190828614)
  46. GRB 190828C: Fermi GBM Final Real-time Localization
  47. GRB 190828B: Fermi GBM Final Real-time Localization
  48. LIGO/Virgo S190814bv: DESGW non-detection of AT2019osy/ASKAP 005547-270433
  49. Fermi trigger No 588597173 Global MASTER-Net observations report
  50. Fermi GBM-190816: Eight additional candidates from the Zwicky Transient Facility
  51. GRB 190827A: BALROG localization (Fermi Trigger 588597173 / GRB 190827467)
  52. GRB 190827A: Fermi GBM Final Real-time Localization
  53. LIGO/Virgo S190814bv: Final list of candidates from the DESGW coadd analysis from the week long search campaign
  54. Fermi trigger No 588398821 Global MASTER-Net observations report
  55. GRB 190825A: Fermi GBM Final Real-time Localization
  56. GRB 190824A: Fermi GBM observation
  57. Fermi trigger No 588350802 Global MASTER-Net observations report
  58. Fermi GBM-190816: Updated localization of subthreshold GRB-GW candidate
  59. GRB 190824A: Fermi GBM Final Real-time Localization
  60. Fermi trigger No 588185734 Global MASTER-Net observations report
  61. Fermi GBM-190816: Coverage and upper limits from MAXI/GSC observations
  62. Fermi trigger No 588115134 Global MASTER-Net observations report
  63. Fermi GBM-190816: MASTER-Net optical observation report
  64. LIGO/Virgo S190814bv: new candidate from DESGW
  65. GRB 190821A: Fermi GBM observation
  66. Fermi GBM-190816: Upper Limits from Swift/BAT Observations
  67. Fermi GBM-190816: Correction from the Zwicky Transient Facility
  68. Fermi GBM-190816: Four additional candidates from the Zwicky Transient Facility
  69. Fermi trigger No 588100239 Global MASTER-Net observations report
  70. Fermi GBM-190816: No counterpart candidates in Fermi-LAT observations
  71. LIGO/Virgo S190814bv: further candidates from DESGW
  72. Fermi GBM-190816: AGILE in SAA at T0
  73. Fermi GBM-190816: ZTF19abqanpy 10.4m GTC spectroscopy
  74. Fermi-LAT Gamma-ray Observations of IceCube-190819A
  75. Fermi GBM-190816: One candidate counterpart from the Zwicky Transient Facility
  76. LIGO/Virgo GBM-190816: no counterpart candidates in the Swift/BAT Observations
  77. Fermi GBM-190816: Upper limits from IceCube neutrino searches
  78. IceCube-190819A: MASTER analysis
  79. Fermi GBM-190816: No counterpart candidates in HAWC observations
  80. Fermi GBM-190816+LIGO/Virgo : no neutrino counterpart candidate in ANTARES search
  81. Fermi GBM-190816: Location-dependent upper limits from INTEGRAL/SPI-ACS prompt observation
  82. Fermi GBM-190816: A subthreshold GRB candidate potentially associated with a subthreshold LIGO/Virgo compact binary merger candidate
  83. IceCube-190819A: Upper limits from Fermi-GBM Observations
  84. IceCube-190819A - IceCube observation of a high-energy neutrino candidate event
  85. LIGO/Virgo S190814bv: DESGW candidate update
  86. Fermi trigger No 587775150 Global MASTER-Net observations report
  87. GRB 190817A: Fermi GBM Final Real-time Localization
  88. LIGO/Virgo S190814bv: Fermi-LAT search for a high-energy gamma-ray counterpart
  89. LIGO/Virgo S190814bv: New candidates from DECam DESGW difference imaging search
  90. GRB 190813A: Insight-HXMT/HE detection
  91. GRB 190814A: Insight-HXMT/HE detection
  92. LIGO/Virgo S190814bv: No candidates identified in DECam data by visual inspection
  93. Fermi trigger No 587505927 Global MASTER-Net observations report
  94. LIGO/Virgo S190814bv: Candidates found in initial DESGW search
  95. IPN triangulation of GRB 190813A (short)
  96. LIGO/Virgo S190814bv: Upper limits from Fermi-GBM Observations
  97. GRB 190814A: Fermi GBM Final Real-time Localization
  98. Fermi trigger No 587392154 Global MASTER-Net observations report
  99. GRB 190813A: Fermi GBM Final Real-time Localization
  100. IPN triangulation of GRB 190805B

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