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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"

28084 results found.

  1. Fermi-LAT Gamma-ray Observations of IceCube-200614A and detection of a new gamma-ray source, Fermi J0202.8+3132
  2. LIGO/Virgo MS200615ce: Identification of a test binary black hole candidate
  3. GRB 200613A: CALET Gamma-Ray Burst Monitor detection
  4. LIGO/Virgo MS200614bz: Test Identification of a binary neutron star candidate
  5. GRB 200613A: MITSuME Akeno optical upper limits
  6. GRB 200615B: MAXI/GSC detection
  7. IceCube-200614A: Upper limits from a search for additional neutrino events in IceCube
  8. IceCube-200615A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  9. IceCube-200614A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  10. LIGO/Virgo MS200615h: Retraction of a test binary neutron star candidate
  11. GRB 200613A: Continued Xinglong-2.16m optical observations
  12. GRB 200613A: Swift/UVOT Detection
  13. GRB 200613A: Xinglong-2.16m optical observations
  14. GRB 200613A: Liverpool Telescope observations
  15. GRB 200613A: Swift-XRT afterglow detection
  16. GRB 200612A: Fermi GBM detection
  17. GRB 200613A: Fermi GBM observation
  18. GRB 200612A: Swift/UVOT Upper Limits
  19. Baksan Neutrino Observatory Alert 200611.74: Global MASTER-Net observations report
  20. BALROG localization (Fermi Trigger 613719013 / GRB 200613229)
  21. GRB 200612A: Swift-BAT refined analysis
  22. GRB 200612A: Swift-XRT refined Analysis
  23. Konus-Wind observation of ultra-long GRB 200612A
  24. GRB 200612A: Enhanced Swift-XRT position
  25. Swift GRB200612.19: Global MASTER-Net OT detection
  26. GRB 200612A: Swift detection of a burst
  27. GRB 200609A: Insight-HXMT/HE detection
  28. GRB 200608A: Swift-BAT refined analysis
  29. GRB 200608A: Swift detection of a burst
  30. GRB 200607B: AstroSat CZTI detection
  31. IPN triangulation of GRB 200605A (short)
  32. GRB 200607A: BALROG localization (Fermi Trigger 613212114 / GRB 200607362)
  33. GRB 200530A: Fermi GBM detection
  34. 1RXS J1708−4009: Swift-BAT refined analysis
  35. GRB 200604A: AstroSat CZTI detection
  36. GRB 200529A: Swift/UVOT Upper Limits
  37. Konus-Wind observation of GRB200528A
  38. GRB 200601A: Insight-HXMT/HE detection
  39. IceCube-200530A: Upper limits from a search for additional neutrino events in IceCube
  40. Fermi-LAT Gamma-ray Observations of IceCube-200530A
  41. GRB 200529A: MITSuME Akeno optical upper limits
  42. GRB 200601A: Fermi GBM Final Real-time Localization
  43. IceCube-200530A: No significant detection in HAWC
  44. IceCube-200530A: Candidate Counterparts from the Zwicky Transient Facility
  45. IceCube-200530A: No ANTARES neutrino counterpart
  46. GRB 200529A: Swift-BAT refined analysis
  47. IceCube-200530A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  48. GRB 200529A: Swift-XRT refined Analysis
  49. GRB 200529A: Fermi GBM Detection
  50. GRB 200529A: LCO Optical Afterglow Detection
  51. GRB 200528A: Swift-XRT refined Analysis
  52. GRB 200528A: Assy optical upper limit
  53. GRB 200529A: Enhanced Swift-XRT position
  54. GRB 200529A: KAIT Optical Afterglow Confirmation
  55. GRB 200529A: NOT optical afterglow
  56. GRB 200529A: Swift detection of a burst
  57. GRB 200528A: NOT optical upper limits
  58. GRB 200528A: Fermi GBM Observation
  59. GRB 200528A: Swift/UVOT Upper Limits
  60. GRB 200528A: Swift-BAT refined analysis
  61. GRB 200528A: Nanshan/NEXT optical upper limit
  62. GRB 200528A: Enhanced Swift-XRT position
  63. GRB 200528A: MITSuME Akeno optical upper limits
  64. GRB 200528A: Swift detection of a burst
  65. GRB 200524A: Assy optical observations
  66. IceCube-200523A: Upper limits from a search for additional neutrino events in IceCube
  67. GRB 200522A: Hubble Space Telescope Near-IR F160W Observations
  68. GRB 200524A: optical upper limits from further MITSuME Akeno observation
  69. GRB 200522A: Gemini North optical imaging
  70. GRB 200524A: AstroSat CZTI detection
  71. GRB 200524A: Further Liverpool Telescope observations
  72. Fermi-LAT Gamma-ray Observations of IceCube-190523A
  73. GRB200521A: ASIM observation
  74. GRB 200524A: KAIT Optical Observations
  75. GRB 200524A: MITSuME Akeno optical observation
  76. GRB 200524A: Swift-XRT afterglow detection
  77. GRB 200524A: OAJ multicolor afterglow detection
  78. GRB 200524A: Fermi GBM detection
  79. GRB 200524: Swift/UVOT observations missed the ZTF20abbiixp position
  80. GRB 200524A: CAHA multicolor afterglow detection
  81. GRB 200524A: Correction to the GCN 27800
  82. GRB 200524A: 3.6m DOT observations of the afterglow candidate ZTF20abbiixp
  83. GRB 200524A: GROWTH-India confirmation of optical afterglow
  84. GRB 200522A: Swift-BAT refined analysis
  85. GRB 200522A: LCO Optical Afterglow Detection
  86. GRB 200522A: 6 GHz VLA radio source detection
  87. GRB 200522A: Swift-XRT refined Analysis
  88. GRB 200522A: Swift/UVOT Upper Limits
  89. GRB 200522A: Enhanced Swift-XRT position
  90. GRB 200522A: Swift detection of a short burst
  91. GRB 200519A: Swift-BAT refined analysis
  92. GRB 200519A: Insight-HXMT/HE detection
  93. GRB 200519A: Swift/UVOT Detection
  94. GRB 200519A: GROWTH-India optical follow-up
  95. GRB 200519A: AstroSat CZTI detection
  96. GRB 200519A: Swift-XRT refined Analysis
  97. GRB 200519A: Enhanced Swift-XRT position
  98. GRB 200519A: LCO Optical Afterglow Detection
  99. Fermi GBM Sub-Threshold Detection of GRB 200517A
  100. GRB 200519A: iTelescope optical afterglow detection

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