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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"
  1. LIGO/Virgo S190517h: CALET Observations
  2. LIGO/Virgo S190426c: NICER X-ray Follow-Up of ZTF19aassfws
  3. LIGO/Virgo S190518bb: Retraction of GW compact binary merger candidate
  4. LIGO/Virgo S190518bb Global MASTER-Net observations report
  5. LIGO/Virgo S190517h: INTEGRAL prompt observation
  6. Fermi GRB190517.81 Global MASTER-Net observations report
  7. GRB 190511A: Swift/UVOT further analysis
  8. Fermi Trigger 579814215 / GRB 190517813 / GRB190517A: BALROG localization
  9. GRB 190517A: Fermi GBM Final Real-time Localization
  10. LIGO/Virgo S190512at: Updated sky localization
  11. LIGO/Virgo S190517h: Fermi-LAT search for a high-energy gamma-ray counterpart
  12. LIGO/Virgo S190517h: Swift/BAT Counterpart Search
  13. LIGO/Virgo S190517h: ANTARES neutrino search
  14. LIGO/Virgo S190517h: Insight-HXMT/HE observations
  15. LIGO/Virgo S190517h: Fermi GBM Observations
  16. LIGO/Virgo S190517h: HAWC follow-up
  17. LIGO/Virgo S190517h: MAXI/GSC Observations
  18. LIGO/Virgo S190517h Global MASTER-Net observations report
  19. GRB 190515A: CALET Gamma-Ray Burst Monitor detection
  20. LIGO-Virgo S190517h: AGILE GRID observations
  21. LIGO/Virgo S190517h: IceCube Neutrino Search
  22. LIGO/Virgo S190517h: AGILE MCAL observations
  23. LIGO/Virgo S190517h: INTEGRAL/SPI-ACS prompt observation
  24. LIGO/Virgo S190517h: Identification of a GW compact binary merger candidate
  25. Fermi GRB190517.1 Global MASTER-Net observations report
  26. GRB 190515B: Swift/UVOT Upper Limits
  27. GRB 190515B: BOOTES-4/MET and 2.2m CAHA optical limits
  28. LIGO/Virgo S190513bm: Swope follow-up observations
  29. Fermi GRB190515.49 Global MASTER-Net observations report
  30. GRB 190515B: Swift-BAT refined analysis
  31. GRB 190515A: Insight-HXMT/HE detection
  32. GRB 190515A: Fermi GBM detection
  33. GRB 190515B: Swift-XRT refined Analysis
  34. GRB 190515A: Fermi-LAT detection
  35. Fermi GRB190515.43 Global MASTER-Net observations report
  36. GRB 190515B: Optical observations from OSN
  37. GRB 190515B: Enhanced Swift-XRT position
  38. GRB 190515B: Kitab Observatory optical upper limit
  39. Correction to GRB name for Swift trigger 903845
  40. GRB 190515B: Prompt enhanced Swift-XRT position
  41. GRB 190515B: Swift detection of a burst
  42. GRB 190510A: CALET Gamma-Ray Burst Monitor detection
  43. LIGO/Virgo S190426c: AMI-LA radio observations of ZTF19aassfws
  44. GRB 190515A: Fermi GBM Final Real-time Localization
  45. LIGO/Virgo S190513bm : TAROT-Calern and TAROT-Chile (TCA/TCH)/GRANDMA observation report.
  46. LIGO/Virgo S190513bm: CALET Observations
  47. Fermi GRB190514.67 Global MASTER-Net observations report
  48. LIGO/Virgo S190513bm: Lick/KAIT Follow-Up Observations
  49. LIGO/Virgo S190503bf: Gaia Photometric Alerts transient candidate
  50. LIGO/Virgo S190510g: Gaia Photometric Alerts transient candidate
  51. LIGO/Virgo S190513bm: Swift/BAT Counterpart Search
  52. LIGO/Virgo S190513bm: Insight-HXMT/HE observation
  53. LIGO/Virgo S190510g: Swift-XRT observations and results
  54. LIGO/Virgo S190510g: DECam-GROWTH optical counterpart candidate DG19qcso
  55. LIGO/Virgo S190513bm: ANTARES neutrino search
  56. GRB 190510B: AstroSat CZTI detection
  57. LIGO/Virgo S190513bm: Fermi GBM Observations
  58. GRB 180416D: AstroSat CZTI detection
  59. LIGO/Virgo S190510g: AT2019ezb and AT2019far 10.4m GTC spectroscopy
  60. Konus-Wind observation of GRB 190511A
  61. Konus-Wind observation of GRB 190510A
  62. LIGO/Virgo S190513bm: Fermi-LAT search for a high-energy gamma-ray counterpart
  63. LIGO/Virgo S190512at: CALET Observations
  64. LIGO/Virgo S190513bm: MAXI/GSC Observations
  65. LIGO/Virgo S190510g: Further KMTNet observation of DECam-GROWTH and DESGW candidates
  66. LIGO/Virgo S190513bm: AGILE GRID observations
  67. LIGO/Virgo S190513bm: INTEGRAL prompt observation
  68. LIGO/Virgo S190513bm: AGILE MCAL observation
  69. LIGO/Virgo S190513bm Global MASTER-Net observations report
  70. LIGO/Virgo S190513bm: IceCube Neutrino Search
  71. LIGO/Virgo S190513bm: HAWC follow-up
  72. LIGO/Virgo S190513bm: Identification of a GW compact binary merger candidate
  73. LIGO/Virgo S190512at: Insight-HXMT/HE observation
  74. GRB 190512A: Swift-BAT refined analysis
  75. LIGO-Virgo S190512at: AGILE GRID observations
  76. LIGO/Virgo S190512at: Swift/BAT Counterpart Search
  77. LIGO/Virgo S190510g: Pan-STARRS and ATLAS observations and candidates
  78. LIGO/Virgo S190512at: ANTARES neutrino search
  79. LIGO/Virgo S190512at: Fermi-LAT search for a high-energy gamma-ray counterpart
  80. LIGO/Virgo S190512at: MAXI/GSC Observations
  81. LIGO/Virgo S190512at: Fermi GBM Observations
  82. LIGO/Virgo S190512at Global MASTER-Net observations report
  83. LIGO/Virgo S190510g: Spectroscopic Classification of DECam-GROWTH and DES-GW Candidate DG19fqqk/desgw-190510c with Magellan
  84. GRB 190512A: Fermi GBM observation
  85. LIGO/Virgo S190510g: MASTER OT detection inside PGC087378 galaxy
  86. LIGO/Virgo S190512at: INTEGRAL inactive at the time of the event
  87. LIGO-Virgo S190512at: AGILE MCAL observations
  88. Fermi GRB190512.62 Global MASTER-Net observations report
  89. Fermi GRB190512.61 Global MASTER-Net observations report
  90. LIGO/Virgo S190512at: IceCube Neutrino Search
  91. LIGO/Virgo S190512at: Identification of a GW compact binary merger candidate
  92. GRB 190511A: Swift-BAT refined analysis
  93. GRB 190512A: Swift detection of a burst
  94. GRB 190512A: Fermi GBM Final Real-time Localization
  95. GRB 190511A: Swift-XRT refined Analysis
  96. IPN triangulation of GRB 190510A (short)
  97. LIGO/Virgo S190510g: DOAO Observation
  98. LIGO/Virgo S190510g: CALET Observations
  99. GRB 190511A: Swift/UVOT Detection
  100. LIGO/Virgo S190510g: KMTNet observation of DECam-GROWTH and DESGW candidates

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