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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

43952 results found.

  1. INTEGRAL observation of IceCube HESE 65274589 129281
  2. GRB 170311A: Swift-BAT refined analysis
  3. LIGO/Virgo G275697: GRAWITA NOT optical observations of Swift/XRT Source 23
  4. GRB 170311A: Swift-XRT refined Analysis
  5. GRB 170311A: Enhanced Swift-XRT position
  6. SN MASTER OT J042250.16-820415.4 is the possible optical counterpart of the gravitational waves event LIGO/Virgo G274296
  7. GRB 170311A: GROND upper limits
  8. GRB 170311A: MASTER-OAFA early optical observations
  9. GRB 170311A: Swift detection of a burst
  10. GRB 170309A: POLAR Observation
  11. GRB170306A: SALT observations
  12. GRB 170306A: GROND afterglow detection
  13. LIGO/Virgo G275404: Swift-XRT observations of sources in the AGILE error region
  14. LIGO/Virgo G275697: Swift-XRT source 23 is fading
  15. LIGO/Virgo G275404: Updated localization from LIGO data
  16. GRB 170306B: POLAR observation
  17. GRB 170307A (trigger 741528): Swift-BAT refined analysis
  18. GRB 170305A: POLAR observation
  19. Swift trigger 741567: MASTER red star flare detection
  20. GRB 170307A: Fermi GBM observation
  21. LIGO/Virgo G275404 and AGL J1914+1043: INTEGRAL follow-up
  22. LIGO/Virgo G275697: Updated localization from LIGO data
  23. Swift Trigger 741528: a possible GRB
  24. Konus-Wind observation of GRB 170306B
  25. GRB 170306B: Swift-XRT observations
  26. GRB 170306A, Swift-BAT refined analysis
  27. GRB 170306A: Swift-XRT refined Analysis
  28. GRB 170306B: Fermi GBM detection
  29. GRB 170306B: Fermi-LAT detection
  30. GRB 170306B: Tiled Swift observations
  31. IPN Triangulation of GRB 170305A (short)
  32. LIGO/Virgo G275697: Further Swift-XRT sources
  33. GRB 170306A: LCO Cerro Tololo observations
  34. GRB 170306A: Swift detection of a burst
  35. GRB170305A: Fermi GBM detection
  36. LIGO/Virgo G275697: Liverpool Telescope classification of EM candidates
  37. LIGO/Virgo G275404: Liverpool Telescope classification of EM candidates
  38. GRB 170304A: Fermi GBM observation
  39. LIGO/Virgo G275697: Further Swift-XRT sources
  40. LIGO/Virgo G275404: HAWC follow-up
  41. LIGO/Virgo G275404: PIRATE Observations
  42. LIGO/Virgo G275404: Liverpool Telescope classification of EM candidates
  43. LIGO/Virgo G275697: Liverpool Telescope classification of EM candidates
  44. LIGO/Virgo G275697: Further Swift-XRT sources
  45. Konus-Wind observation of GRB 170228A
  46. Fermi GBM trigger 510207699/170303182 is not a GRB
  47. LIGO/Virgo G275697: MAXI/GSC observations
  48. GRB 170228B CALET Gamma-Ray Burst Monitor detection
  49. LIGO/Virgo G275697: Additional iPTF Optical Transient Candidates
  50. LIGO/Virgo G275404: Additional iPTF Optical Transient Candidates
  51. LIGO/Virgo G275404: Nearby Galaxies in the Localization Volume
  52. LIGO/Virgo G275697: Further Swift-XRT sources
  53. LIGO/Virgo G275697: Fermi GBM Upper Limits
  54. LIGO/Virgo G275697: AstroSat CZTI upper limits
  55. LIGO/Virgo G275697: optical spectroscopy of Swift/XRT source 1
  56. LIGO/Virgo G268556, G270580, G274296, and G275404: Konus-Wind observations
  57. LIGO/Virgo G275697: SVOM/Mini-GWAC observations of the initial skymap
  58. GRB 170228B: POLAR Observation
  59. LIGO/Virgo G275697: iPTF Optical Transient Candidates
  60. LIGO/Virgo G275404: iPTF Optical Transient Candidates
  61. LIGO/Virgo G275404: Fermi GBM Upper Limits
  62. GRB 170228A: AstroSat CZTI detection
  63. GRB 170206B: 15 GHz upper limits from AMI
  64. GRB 170228A: Fermi GBM observation
  65. GRB 170228A: Fermi-LAT detection
  66. LIGO/Virgo G275404: A near-infrared transient in the error circle of AGL J1914+1043
  67. LIGO/Virgo G275697: CALET Observations
  68. LIGO/Virgo G275697: MASTER automatic follow up detection
  69. LIGO/Virgo G275697: CNEOST optical observations
  70. LIGO/Virgo G274296 and G275404 : MAXI/GSC observations
  71. LIGO/Virgo G275404: Nearby Galaxies in the Localization Region
  72. LIGO/Virgo G275697: Fermi-LAT search for a high-energy gamma-ray counterpart
  73. LIGO/Virgo G275697: REM optical/NIR observations
  74. LIGO/Virgo G275697: Konus-Wind observations
  75. LIGO/Virgo G275404: CNEOST optical observations
  76. LIGO/Virgo G275697: Swift-XRT sources
  77. LIGO/Virgo G275697: Swift/BAT data search
  78. LIGO/Virgo G275404: MASTER bright PSN detected on 27 Feb from the maximum of probability of LIGO localization
  79. LIGO/Virgo G275697: AGILE-GRID preliminary analysis
  80. LIGO/Virgo G275697: AGILE MCAL Observations
  81. LIGO/Virgo G275697: INTEGRAL search for a prompt gamma-ray counterpart
  82. LIGO/VIRGO G275697: Fermi GBM Observations
  83. LIGO/Virgo G275404: AstroSat CZTI upper limits
  84. LIGO/Virgo G275697 ANTARES search
  85. LIGO/Virgo G275697: IceCube neutrino observations
  86. LIGO/Virgo G275697: Identification of a GW CBC Candidate
  87. LIGO/Virgo G275404: Keck LRIS classification of MASTER PSN candidate
  88. LIGO/Virgo G274296: MASTER new PSN detected on 22 feb
  89. LIGO/Virgo G275404: REM optical/NIR observations
  90. LIGO/Virgo G275404: MASTER PSN detection from the maximal probability LIGO region
  91. LIGO/Virgo G275404: Keck spectrum of MASTER OT J105958.00-115756.5
  92. LIGO/Virgo G275404: Fermi-LAT search for a high-energy gamma-ray counterpart
  93. LIGO/Virgo G275404: INTEGRAL search for a prompt gamma-ray counterpart
  94. LIGO/Virgo G275404: AGILE-GRID detection of a possible gamma-ray transient
  95. LIGO/Virgo G275404: NOT Follow-up of MASTER OT
  96. LIGO/Virgo G275404: Swift-XRT sources
  97. LIGO/Virgo G275404 ANTARES search
  98. LIGO/Virgo G275404: Follow-up of MASTER OT J173532.70+103810.5
  99. GRB 170222A: CALET Gamma-Ray Burst Monitor detection
  100. LIGO/Virgo G275404: MASTER bright OT detection

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