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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').

2299 results found.

  1. Fermi GRB 240502A: Global MASTER-Net observations report
  2. GRB 240502B: Fermi GBM Final Real-time Localization
  3. LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet Transient Candidates
  4. Fermi trigger No 736197684: Global MASTER-Net observations report
  5. GRB 240501B: AstroSat CZTI detection
  6. GRB 240408B: VZLUSAT-2 detection
  7. LIGO/Virgo/KAGRA S240422ed: ENGRAVE VLT/XShooter spectroscopy of the host galaxy of J-GEM24a
  8. GRB 240426A: AstroSat CZTI detection
  9. EP240426a: YAHPT optical upper limit
  10. LIGO/Virgo/KAGRA S240422ed: Continued Magellan Observations
  11. LIGO/Virgo/KAGRA S240422ed: Further near-infrared observations with Subaru/MOIRCS by J-GEM Collaboration
  12. GRB 240425A: Fermi GBM Final Real-time Localization
  13. LIGO/Virgo/KAGRA S240422ed: No significant candidates in GRANDMA/FRAM Observations
  14. LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
  15. LIGO/Virgo/KAGRA S240422ed: Continued Imaging of Mag24a
  16. GRB 240421B: GRBAlpha detection
  17. LIGO/Virgo/KAGRA S240422ed: No Counterparts in DDOTI/OAN Optical Observations
  18. GRB 240419A: Possible ATCA radio detection
  19. LIGO/Virgo/KAGRA S240422ed: Magellan Observations
  20. GRB 240414A: radio detection with the VLA
  21. GRB 240421B: AstroSat CZTI detection
  22. GRB240421B: Zadko Observations
  23. Fermi GRB 240421B: Global MASTER-Net observations report
  24. Swift GRB 240421B: Global MASTER-Net observations report
  25. GRB 240421B: Fermi GBM Observation
  26. GRB 240421B: Swift-XRT refined Analysis
  27. GRB 240421B: Swift detection of a burst
  28. Fermi trigger No 735280430: Global MASTER-Net observations report
  29. IceCube Alert 240419.98: Global MASTER-Net observations report
  30. GRB 240419A: VLT/UVES redshift of z = 5.178
  31. EP240414a: GMG observation
  32. GRB 240418A: AKO Upper Limit
  33. Fermi GRB 240417A: Global MASTER-Net observations report
  34. EP240416a: BOOTES-2/TELMA Optical Upper Limit
  35. GRB 240417A: Fermi GBM Final Real-time Localization
  36. EP240416A: MASTER optical observations
  37. EP240416a: EP-WXT detection of a fast X-ray transient
  38. Fermi GRB 240415A: Global MASTER-Net observations report
  39. GRB 240414A: Photometric observation from 2.2m CAHA
  40. IceCube-240412A: Upper limits from a search for additional neutrino events in IceCube
  41. GRB 240415A: Fermi GBM Final Real-time Localization
  42. EP240413A: GOTO optical upper limits
  43. Fermi trigger No 734754044: Global MASTER-Net observations report
  44. LIGO/Virgo/KAGRA S240413p: Global MASTER-Net observations report
  45. GRB 240408B: AstroSat CZTI detection
  46. Fermi GRB 240407A: Global MASTER-Net observations report
  47. LXT 240402A: MASTER optical observations with AGN in error-box
  48. Fermi GRB 240402A: Global MASTER-Net observations report
  49. GRB 240329A: Glowbug gamma-ray detection
  50. GRB 240324A: AstroSat CZTI detection of a short burst
  51. GRB 240331A: AstroSat CZTI detection
  52. GRB 240329A: AstroSat CZTI detection
  53. Fermi trigger No 733366352: Global MASTER-Net observations report
  54. Fermi trigger No 732937833: Global MASTER-Net observations report
  55. Fermi GRB 240320A: Global MASTER-Net observations report
  56. X-ray transient EP 240315a: Chandra observations
  57. X-ray transient EP240315a: EP-FXT detection of the X-ray afterglow
  58. GRB 240317A: AstroSat CZTI detection
  59. GRB 240315B: AstroSat CZTI detection
  60. Fermi GRB 240317B: Global MASTER-Net observations report
  61. Fermi trigger No 732299243: Global MASTER-Net observations report
  62. Fermi GRB 240314A: Global MASTER-Net observations report
  63. Fermi trigger No 731839490: Global MASTER-Net observations report
  64. IceCube Alert 240307.32: Global MASTER-Net observations report
  65. GRB 240306A: AstroSat CZTI detection
  66. GRB 240305C: AstroSat CZTI detection of a short burst
  67. Improved IPN triangulation of GRB 240227A (short)
  68. Swift Trigger 1218701: Yes, we triggered on Swift J151857.0-572147 again
  69. Fermi GRB 240229A: Global MASTER-Net observations report
  70. GRB 240225C: AstroSat CZTI detection
  71. GRB 240225B: AstroSat CZTI detection
  72. Transient EPW20240219aa: 7DT Optical Upper Limits
  73. Transient EPW20240219aa: upper limit in gamma-ray range from SPI-ACS/INTEGRAL observations
  74. Insight-HXMT/HE Sub-Threshold Detection of Transient EPW20240219aa
  75. Transient EPW20240219aa: Liverpool Telescope non-detection and limiting magnitude
  76. Fermi GBM Sub-Threshold Detection of EPW20240219aa as a likely GRB
  77. EPW20240219aa is Likely a GRB Event
  78. Fermi trigger No 729914426: Global MASTER-Net observations report
  79. GRB 240209A: Wendelstein Optical Observations
  80. Fermi trigger No 729152364: Global MASTER-Net observations report
  81. GRB 240205B: AstroSat CZTI detection
  82. Fermi trigger No 729012023: Global MASTER-Net observations report
  83. GRB 240204A: AstroSat CZTI detection
  84. GRB 240205B: Skynet Optical Afterglow Observations
  85. Fermi trigger No 728749569: Global MASTER-Net observations report
  86. IceCube Alert 240204.38: Global MASTER-Net observations report
  87. GRB 240201A: AstroSat CZTI detection
  88. GRB 240125A: AstroSat CZTI detection of a short burst
  89. GRB 240124B: AstroSat CZTI detection
  90. GRB 240123C: AstroSat CZTI detection
  91. IPN triangulation of GRB 240123C (short)
  92. GRB 240123A: SAO RAS optical observations
  93. Fermi GRB 240123B: Global MASTER-Net observations report
  94. GRB 240122A: GOTO optical counterpart candidate
  95. GRB 240119A: AstroSat CZTI detection of a short burst
  96. GRB 240118D: AstroSat CZTI detection
  97. GRB 240117A: AstroSat CZTI detection
  98. IPN triangulation of GRB 240112A (long)
  99. GRB 240115B: AstroSat CZTI detection
  100. Fermi trigger No 726773850: Global MASTER-Net observations report

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