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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. IceCube-200620A: MASTER previous detection of ZTF20abgvabi/AT2020ncr
  2. IceCube-200620A: not observable by Fermi-GBM
  3. IceCube-200620A: One Candidate Counterpart from the Zwicky Transient Facility
  4. Fermi-LAT Gamma-ray Observations of IceCube-200620A
  5. GRB 200613A: Continued CrAO optical observations
  6. IceCube-200620A: No ANTARES neutrino counterpart
  7. IceCube Alert 200620.13: Global MASTER-Net observations report
  8. GRB 200613A: CrAO optical observations
  9. GRB 200613A: R-band observations from HCT
  10. GRB 200613A: Further Liverpool Telescope observations
  11. IceCube-200620A - IceCube observation of a high-energy neutrino candidate track-like event
  12. GRB 200619C: Fermi GBM Final Real-time Localization
  13. Fermi GRB 200619B: Global MASTER-Net observations report
  14. GRB 200619B: AstroSat CZTI detection
  15. GRB 200619A: Fermi GBM observation
  16. Fermi trigger No 614239407: Global MASTER-Net observations report
  17. GRB 200619A: AGILE detection
  18. LIGO/Virgo MS200618aq: Retraction of a test binary neutron star candidate
  19. LIGO/Virgo MS200619bf: Retraction of a test binary neutron star candidate
  20. LIGO/Virgo MS200618bx: Retraction of a test binary neutron star candidate
  21. LIGO/Virgo MS200618bq: Retraction of a test binary neutron star candidate
  22. GRB 200619B: Fermi GBM Final Real-time Localization
  23. GRB 200619A: Insight-HXMT/HE detection
  24. Fermi trigger No 614226976: Global MASTER-Net observations report
  25. GRB 200613A: continued Kitab optical observations
  26. GRB 200613A: SAO RAS optical observations
  27. GRB 200617A: Insight-HXMT/HE detection
  28. IceCube-200530A - SN2020lls likely unrelated
  29. Swift/UVOT Observations of IceCube 200615A
  30. GRB 200613A: Mondy optical observations
  31. LIGO/Virgo MS200614ct: Identification of a test binary black hole candidate
  32. Fermi trigger No 614103490: Global MASTER-Net observations report
  33. Baksan Neutrino Observatory Alert 200617.47: Global MASTER-Net observations report
  34. GRB 200615B: CALET Gamma-Ray Burst Monitor detection
  35. Swift-XRT observations of IceCube 200615A
  36. IceCube-200615A: No significant detection in HAWC
  37. GRB 200613A: Jet-break from Xinglong-2.16m optical observations
  38. Fermi-LAT Gamma-ray Observations of IceCube-200615A
  39. IceCube-200614A: No significant detection in HAWC
  40. IceCube-200615A: Upper limits from a search for additional neutrino events in IceCube
  41. GRB 200616B: Fermi GBM Final Real-time Localization
  42. Fermi-LAT Gamma-ray Observations of IceCube-200614A and detection of a new gamma-ray source, Fermi J0202.8+3132
  43. LIGO/Virgo MS200615ce: Identification of a test binary black hole candidate
  44. GRB 200613A: CALET Gamma-Ray Burst Monitor detection
  45. LIGO/Virgo MS200614bz: Test Identification of a binary neutron star candidate
  46. GRB 200613A: MITSuME Akeno optical upper limits
  47. Fermi GRB 200616A: Global MASTER-Net observations report
  48. GRB 200615B: MAXI/GSC detection
  49. GRB 200616A: Fermi GBM Final Real-time Localization
  50. GRB 200613A: continued AbAO optical afterglow observations
  51. IceCube-200615A: Upper limits from Fermi-GBM Observations
  52. IceCube-200614A: Upper limits from a search for additional neutrino events in IceCube
  53. IceCube-200614A: not observable by Fermi-GBM
  54. IceCube-200615A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  55. IceCube Alert 200615.62: Global MASTER-Net observations report
  56. IceCube-200614A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  57. LIGO/Virgo MS200615h: Retraction of a test binary neutron star candidate
  58. IceCube-200615A: IceCube observation of a high-energy neutrino candidate event
  59. GRB 200613A: Continued Xinglong-2.16m optical observations
  60. Fermi GRB 200615A: Global MASTER-Net observations report
  61. GRB 200615A: Fermi GBM Final Real-time Localization
  62. Baksan Neutrino Observatory Alert 200614.34: Global MASTER-Net observations report
  63. IceCube Alert 200614.53: Global MASTER-Net observations report
  64. GRB 200613A: Swift/UVOT Detection
  65. GRB 200613A: Xinglong-2.16m optical observations
  66. Fermi GRB 200614A: Global MASTER-Net observations report
  67. IceCube-200614A - IceCube observation of a high-energy neutrino candidate track-like event
  68. GRB 200614A: Fermi GBM Final Real-time Localization
  69. GRB 200613A: Liverpool Telescope observations
  70. GRB 200613A: OAJ Afterglow: Error in Coordinates
  71. GRB 200613A: Kitab and AbAO optical afterglow observations, host galaxy candidate
  72. GRB 200613A: Swift-XRT afterglow detection
  73. GRB 200613A: Candidate afterglow from OAJ
  74. GRB 200612A: Fermi GBM detection
  75. Fermi GRB 200613A: Global MASTER-Net observations report
  76. GRB 200613A: Swift ToO observations
  77. GRB 200613A: Fermi-LAT detection
  78. GRB 200613A: Fermi GBM observation
  79. GRB 200612A: Swift/UVOT Upper Limits
  80. Baksan Neutrino Observatory Alert 200611.74: Global MASTER-Net observations report
  81. BALROG localization (Fermi Trigger 613719013 / GRB 200613229)
  82. GRB 200613A: Fermi GBM Final Real-time Localization
  83. GRB 200612A: Swift-BAT refined analysis
  84. GRB 200612A: Swift-XRT refined Analysis
  85. Konus-Wind observation of ultra-long GRB 200612A
  86. GRB 200612A: Enhanced Swift-XRT position
  87. GRB 200612A: Late Optical Maximum Deteted by MASTER
  88. GRB 200612A: BOOTES-3/YA optical upper limit
  89. Fermi trigger No 613630183: Global MASTER-Net observations report
  90. Swift GRB200612.19: Global MASTER-Net OT detection
  91. Swift GRB200612.19: Global MASTER-Net observations report
  92. GRB 200612A: Swift detection of a burst
  93. GRB 200609A: Insight-HXMT/HE detection
  94. GRB 200608A: Swift-BAT refined analysis
  95. Konus-Wind detection of GRB 200605A
  96. GRB 200605A: CALET Gamma-Ray Burst Monitor detection
  97. IceCube-200530A - SN2020lam classified as SN II without evidence of CSM interaction
  98. GRB 200609A: Fermi GBM Final Real-time Localization
  99. Swift GRB 200608A: Global MASTER-Net observations report
  100. GRB 200608A: BOOTES-3 and BOOTES-4 optical upper limit

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