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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').

3072 results found.

  1. LIGO/Virgo/KAGRA S240422ed: EP-FXT Detection of the Potential Opitcal Electromagnetic Counterpart AT 2024hfq Reported by DECam
  2. LIGO/Virgo/KAGRA S240422ed: Continued Magellan Observations
  3. IceCube-240424A: Upper limits from a search for additional neutrino events in IceCube
  4. LIGO/Virgo/KAGRA S240422ed: Second night Pan-STARRS observations of the skymap
  5. LIGO/Virgo/KAGRA S240422ed: Further near-infrared observations with Subaru/MOIRCS by J-GEM Collaboration
  6. GRB 240421B: Swift-BAT refined analysis
  7. LIGO/Virgo/KAGRA S240422ed: No significant candidates in GRANDMA/FRAM Observations
  8. LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
  9. LIGO/Virgo/KAGRA S240422ed: Continued Imaging of Mag24a
  10. IceCube Alert 240424.08: Global MASTER-Net observations report
  11. LIGO/Virgo/KAGRA S240422ed: Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
  12. LIGO/Virgo/KAGRA S240422ed: Potential Candidates from Magellan galaxy-based search
  13. GRB 240419A: Swift-BAT refined analysis
  14. GRB 240421B: ATCA radio observations
  15. LIGO/Virgo/KAGRA S240422ed: Magellan Observations
  16. LIGO/Virgo/KAGRA S240422ed: Coverage and upper limits from MAXI/GSC observations
  17. Fermi trigger No 735470374: Global MASTER-Net observations report
  18. Fermi trigger No 735280430: Global MASTER-Net observations report
  19. IceCube Alert 240419.98: Global MASTER-Net observations report
  20. GRB 240411A: GOTO early optical upper limits
  21. Fermi GRB 240417A: Global MASTER-Net observations report
  22. LIGO/Virgo/KAGRA S240413p: X-ray upper limits from EP-WXT for the candidate AGN counterpart
  23. EP240416A: Khureltogoot optical upper limit
  24. Improved IPN triangulation of GRB 240411A
  25. EP240416A: MASTER optical observations
  26. GRB 240414A: Swift-BAT refined analysis
  27. Fermi GRB 240415A: Global MASTER-Net observations report
  28. GRB 240415A: Fermi GBM Final Real-time Localization
  29. Fermi trigger No 734754044: Global MASTER-Net observations report
  30. GRB 240414A : OHP/T193 redshift determination
  31. LIGO/Virgo/KAGRA S240413p: Global MASTER-Net observations report
  32. IceCube Alert 240412.23: Global MASTER-Net observations report
  33. EP240408a: Swift follow-up observation
  34. Fermi GRB 240405B: Global MASTER-Net observations report
  35. GRB 240403B: Glowbug gamma-ray detection
  36. GRB 240403A: Glowbug gamma-ray detection
  37. Konus-Wind detection of LXT 240402A/GRB 240402B
  38. GRB 240403A: Fermi GBM Detection
  39. GRB 240403A: BALROG localization (Fermi Trigger 733838255 / GRB 240403498)
  40. Fermi GRB 240402A: Global MASTER-Net observations report
  41. Fermi trigger No 733097506: Global MASTER-Net observations report
  42. Fermi GRB 240320A: Global MASTER-Net observations report
  43. Fermi GRB 240317B: Global MASTER-Net observations report
  44. Fermi trigger No 732299243: Global MASTER-Net observations report
  45. Fermi GRB 240314A: Global MASTER-Net observations report
  46. Fermi GRB 240310A: Global MASTER-Net observations report
  47. GRB 240309A: MAXI/GSC detection
  48. Fermi GRB 240306A: Global MASTER-Net observations report
  49. Fermi GRB 240305A: Global MASTER-Net observations report
  50. Swift J151857.0-572147: Swift-BAT refined analysis
  51. GRB 240225B: Swift-XRT afterglow detection
  52. GRB 240225B: Glowbug gamma-ray detection
  53. Fermi GRB 240229A: Global MASTER-Net observations report
  54. IceCube Alert 240229.66: Global MASTER-Net observations report
  55. GRB 240225B: Swift ToO observations
  56. Konus-Wind detection of GRB 240225B (long)
  57. GRB 240225B: VLT/X-shooter redshift
  58. GRB 240225B : MITSuME Akeno optical afterglow candidate detection
  59. GRB 240225B: 3.6m DOT observation
  60. GRB 240225B: NOT optical observations
  61. GRB 240225B: Nanshan/HMT optical afterglow detection
  62. GRB 240225B: CALET Gamma-Ray Burst Monitor detection
  63. GRB 240225B: Swift-XRT observations
  64. GRB 240225B: GOTO detection of a candidate optical afterglow
  65. Fermi trigger No 730618809: Global MASTER-Net observations report
  66. GRB 240225B: AstroSat CZTI detection
  67. GRB 240225B: Tiled Swift observations
  68. GRB 240225B: MAXI/GSC detection
  69. GRB 240216A: Glowbug gamma-ray detection
  70. GRB 240218A: Swift-BAT refined analysis
  71. GRB 240215A: Fermi GBM Observation
  72. GRB 240216A: GRBAlpha detection
  73. Fermi trigger No 729914426: Global MASTER-Net observations report
  74. GRB 240216A: Fermi GBM Final Real-time Localization
  75. GRB 240128A: Further Swift-XRT observations
  76. GRB 240214A: Tiled Swift observations
  77. GRB 240214A/1H 0451-560: MAXI/GSC detection
  78. Fermi trigger No 729152364: Global MASTER-Net observations report
  79. Fermi trigger No 729012023: Global MASTER-Net observations report
  80. Konus-Wind detection of GRB 240205B (long / very soft)
  81. GRB 240204A: Swift-BAT refined analysis
  82. Fermi trigger No 728749569: Global MASTER-Net observations report
  83. GRB 240204a: Liverpool Telescope optical afterglow detection
  84. GRB 240128A: Glowbug gamma-ray detection
  85. GRB 240128A: Swift-XRT observations
  86. GRB 240128A: GRBAlpha detection
  87. GRB 240128A: Tiled Swift observations
  88. GRB 240128A: CALET Gamma-Ray Burst Monitor detection
  89. GRB 240128A: MAXI/GSC detection
  90. GRB 240122A: ATCA detection of radio counterpart
  91. GRB240122A: PRIME near infrared detection
  92. IceCube Alert 240123.48: Global MASTER-Net observations report
  93. GRB 240122A: Swift/UVOT Upper Limits
  94. GRB 240122A: BOOTES-2/TELMA optical upper limit and 1.5m OSN detection
  95. GRB 240122A: Swift-XRT afterglow detection
  96. GRB 240122A: VLT/X-shooter redshift confirmation
  97. GRB 240122A: Redshift from OSIRIS+/GTC
  98. GRB 240122A: LT non-detection of GOTO candidate counterpart confirms fading
  99. GRB 240122A: GOTO optical counterpart candidate
  100. GRB 240122A: Tiled Swift observations

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