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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').

2982 results found.

  1. LAT GRB240513.31: Global MASTER-Net observations report
  2. Fermi GRB 240513B: Global MASTER-Net observations report
  3. LIGO/Virgo/KAGRA S240513cx: Coverage and upper limits from MAXI/GSC observations
  4. Fermi trigger No 737258655: Global MASTER-Net observations report
  5. Fermi trigger No 737247400: Global MASTER-Net observations report
  6. Fermi trigger No 737152719: Global MASTER-Net observations report
  7. Fermi trigger No 736967879: Global MASTER-Net observations report
  8. Fermi trigger No 736733320: Global MASTER-Net observations report
  9. Fermi trigger No 736564880: Global MASTER-Net observations report
  10. GRB 240502A: Fermi GBM Observation
  11. GRB 240430A: GRBAlpha detection
  12. GRB 240502A long GRB detected by INTEGRAL
  13. GRB 240502A: Fermi GBM Final Real-time Localization
  14. Fermi trigger No 736197684: Global MASTER-Net observations report
  15. GRB 240501B: AstroSat CZTI detection
  16. GRB 240429A: Fermi GBM Final Real-time Localization
  17. LIGO/Virgo/KAGRA S240422ed: ENGRAVE VLT/XShooter spectroscopy of the host galaxy of J-GEM24a
  18. LIGO/Virgo/KAGRA S240428dr: Identification of a GW compact binary merger candidate
  19. Fermi GRB 240428A: Global MASTER-Net observations report
  20. GRB 240428A: Fermi GBM Final Real-time Localization
  21. LIGO/Virgo/KAGRA S240422ed: J-band non-detection of J-GEM24a
  22. LIGO/Virgo/KAGRA S240422ed: EP240426a possible optical detection
  23. LIGO/Virgo/KAGRA S240422ed: Continued Magellan Observations
  24. S240422ed: BlackGEM/MeerLICHT transient detection AT2024hgl/MLTJ080628.10-250116.4
  25. LIGO/Virgo/KAGRA S240422ed: Second night Pan-STARRS observations of the skymap
  26. LIGO/Virgo/KAGRA S240422ed: Further near-infrared observations with Subaru/MOIRCS by J-GEM Collaboration
  27. Fermi trigger No 735697285: Global MASTER-Net observations report
  28. LIGO/Virgo/KAGRA S240422ed: No significant candidates in GRANDMA/FRAM Observations
  29. LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
  30. LIGO/Virgo/KAGRA S240422ed: Continued Imaging of Mag24a
  31. IceCube Alert 240424.08: Global MASTER-Net observations report
  32. LIGO/Virgo/KAGRA S240422ed: Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
  33. LIGO/Virgo/KAGRA S240422ed: Magellan Observations
  34. Fermi GRB 240421B: Global MASTER-Net observations report
  35. Fermi trigger No 735280430: Global MASTER-Net observations report
  36. IceCube Alert 240419.98: Global MASTER-Net observations report
  37. EP240420a: EP-WXT detection of a fast X-ray transient
  38. Fermi GRB 240417A: Global MASTER-Net observations report
  39. LIGO/Virgo/KAGRA S240413p: STEP - T80S Search and Candidate Counterpart Identification
  40. GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
  41. Fermi GRB 240415A: Global MASTER-Net observations report
  42. GRB 240414A: Photometric observation from 2.2m CAHA
  43. Fermi trigger No 734754044: Global MASTER-Net observations report
  44. LIGO/Virgo/KAGRA S240413p: Global MASTER-Net observations report
  45. GRB 240411B: 1.3m DFOT Optical observations
  46. X-ray transient EP240315a: second epoch e-MERLIN radio observations
  47. Fermi GRB 240407A: Global MASTER-Net observations report
  48. X-ray transient LXT 240402A: WFST optical upper limits​
  49. X-ray transient LXT240402A: AST3-3 optical upper limits
  50. LXT 240402A: MASTER optical observations with AGN in error-box
  51. IceCube-240327B: Upper limits from a search for additional neutrino events in IceCube
  52. IceCube-240327A: Upper limits from a search for additional neutrino events in IceCube
  53. Fermi GRB 240329A: Global MASTER-Net observations report
  54. IceCube-240327B: No candidates from the Zwicky Transient Facility
  55. GRB 240328C: Glowbug gamma-ray detection
  56. GRB 240328B: Fermi GBM Final Real-time Localization
  57. GRB 240328A: Fermi GBM Final Real-time Localization
  58. IceCube Alert 240327.68: Global MASTER-Net observations report
  59. Fermi GRB 240320A: Global MASTER-Net observations report
  60. GRB 240315B: AstroSat CZTI detection
  61. Fermi trigger No 732299243: Global MASTER-Net observations report
  62. Fermi trigger No 731839490: Global MASTER-Net observations report
  63. Fermi trigger No 731571927: Global MASTER-Net observations report
  64. GRB 231215A: further radio observations with the VLA
  65. GRB 231028C: Glowbug gamma-ray confirmation of a prior burst
  66. Swift detection of Swift J151857.0-572147
  67. Fermi trigger No 731161136: Global MASTER-Net observations report
  68. IceCube-240229A: Upper limits from a search for additional neutrino events in IceCube
  69. Fermi GRB 240229A: Global MASTER-Net observations report
  70. IceCube Alert 240229.66: Global MASTER-Net observations report
  71. GRB 240225B: 3.6m DOT observation
  72. GRB 240225B: SAO RAS optical observations
  73. Fermi GRB 240227A: Global MASTER-Net observations report
  74. GRB 240225B: MAXI/GSC detection
  75. Fermi trigger No 729914426: Global MASTER-Net observations report
  76. Gamma-ray flaring activity from the blazar 1ES 1959+650 observed by the Fermi-LAT
  77. GRB 240213A: GRBAlpha detection
  78. Fermi trigger No 729703985: Global MASTER-Net observations report
  79. Fermi GRB 240213A: Global MASTER-Net observations report
  80. Fermi trigger No 729152364: Global MASTER-Net observations report
  81. Fermi trigger No 729012023: Global MASTER-Net observations report
  82. Konus-Wind detection of GRB 240205B (long / very soft)
  83. Fermi trigger No 728749569: Global MASTER-Net observations report
  84. Fermi trigger No 728796365: Global MASTER-Net observations report
  85. Fermi GRB 240204A: Global MASTER-Net observations report
  86. Fermi trigger No 728706420: Global MASTER-Net observations report
  87. IceCube Alert 240204.38: Global MASTER-Net observations report
  88. GRB 240129A: Fermi GBM Observation
  89. GRB 240128A: Glowbug gamma-ray detection
  90. GRB 240128A: GRBAlpha detection
  91. GRB 240128A: CALET Gamma-Ray Burst Monitor detection
  92. GRB 240128A: MAXI/GSC detection
  93. GRB 240122A: MAXI/GSC detection
  94. Fermi GRB 240115B: Global MASTER-Net observations report
  95. GRB 240114A: MAXI/GSC detection
  96. Fermi trigger No 726774492: Global MASTER-Net observations report
  97. GRB 230818A: further radio observations with the VLA
  98. IceCube Alert 240105.52: Global MASTER-Net observations report
  99. GRB 240101B: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  100. GRB 231230A: GOTO optical upper limits

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