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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').

3410 results found.

  1. Fermi trigger No 720224759: Global MASTER-Net observations report
  2. LIGO/Virgo/KAGRA S231025t: Global MASTER-Net observations report
  3. LIGO/Virgo/KAGRA S231025a: Global MASTER-Net observations report
  4. IC231004A: GRANDMA observations of AT2023uqf/ZTF23abidzvf candidate
  5. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  6. LIGO/Virgo/KAGRA S231020ba: Identification of a GW compact binary merger candidate
  7. Fermi GRB 231019A: Global MASTER-Net observations report
  8. LIGO/Virgo/KAGRA S231014r: Identification of a GW compact binary merger candidate
  9. GRB 230827B: 10.4m GTC spectroscopic redshift
  10. LIGO/Virgo/KAGRA S230927l: Identification of a GW compact binary merger candidate
  11. LIGO/Virgo/KAGRA S230922g: DECam GW-MMADS candidates
  12. IPN triangulation of GRB 230919A (short)
  13. transient AT2023sva: imaging and spectroscopic observations from MISTRAL at Observatoire de Haute-Provence
  14. LIGO/Virgo/KAGRA S230920al: Identification of a GW compact binary merger candidate
  15. LIGO/Virgo/KAGRA S230919bj: Identification of a GW compact binary merger candidate
  16. IceCube-230914A: Upper limits from a search for additional neutrino events in IceCube
  17. GRB 230911A: Swift-XRT afterglow detection
  18. Fermi trigger No 716449174: Global MASTER-Net observations report
  19. IceCube Alert 230914.22: Global MASTER-Net observations report
  20. GRB 230911A: GOTO optical counterpart candidate
  21. GRB 230906A: Chandra detection of the X-ray afterglow
  22. GRB 230903A: VLT/X-shooter optical observations
  23. GRB 230904C: Fermi GBM Final Localization
  24. Fermi GRB 230903A: Global MASTER-Net observations report
  25. GRB 230904B is not a GRB
  26. GRB 230904B: BALROG localization (Fermi Trigger 715526984 / GRB 230904562)
  27. GRB 230828A: AstroSat CZTI detection
  28. GRB 230828A: GRBAlpha detection
  29. Swift Trigger 1188089 is not a GRB
  30. Fermi GRB 230827A: Global MASTER-Net observations report
  31. GRB 230824A: AKO Photometric Follow-up Observations
  32. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  33. GRB 230818B: VZLUSAT-2 detection
  34. LIGO/Virgo/KAGRA S230820bq: Identification of a GW compact binary merger candidate
  35. GRB 230818A: SAO RAS Zeiss-1000 observations
  36. Fermi GRB 230818A: Global MASTER-Net observations report
  37. GRB 230818A: Swift detection of a burst
  38. Fermi GRB 230817A: Global MASTER-Net observations report
  39. GRB 230816A: TShAO and Assy optical observations
  40. GRB 230816A: SAO RAS optical observations
  41. IPN triangulation of GRB 230815B
  42. GRB 230812B: Fermi-LAT detection
  43. GRB 230812B: Fermi GBM Observation of a very bright burst
  44. LAT GRB230812.79: Global MASTER-Net observations report
  45. GRB 230812B: Fermi GBM detection of an extremely bright GRB
  46. LIGO/Virgo/KAGRA S230802aq: AstroSat CZTI non-detection and upper limits
  47. IceCube-230724A: JCMT/SCUBA-2 submm observations
  48. LIGO/Virgo/KAGRA S230731an: AstroSat CZTI non-detection and upper limits
  49. LIGO/Virgo/KAGRA S230729z: Identification of a GW compact binary merger candidate
  50. LIGO/Virgo/KAGRA S230726a: Identification of a GW compact binary merger candidate
  51. IceCube Alert 230724.08: Global MASTER-Net observations report
  52. GRB 230724A: Fermi GBM Final Real-time Localization
  53. Fermi trigger No 711805358: Global MASTER-Net observations report
  54. Fermi GRB 230723A: Global MASTER-Net observations report
  55. GRB 230707A: Fermi GBM Detection
  56. Fermi GRB 230707A: Global MASTER-Net observations report
  57. Fermi trigger No 710117592: Global MASTER-Net observations report
  58. GRB 230628E: ATCA rapid radio follow-up
  59. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): ALMA 100 GHz Detection
  60. GRB 230628E - VLT spectroscopic observations
  61. Fermi GRB 230628C: Global MASTER-Net observations report
  62. Fermi GRB 230628D: Global MASTER-Net observations report
  63. GRB 230628E: Swift detection of a burst
  64. GRB 230626A: GRBAlpha detection
  65. GRB 230623A: MAXI/GSC detection
  66. LIGO/Virgo S230621ad: Global MASTER-Net observations report
  67. Fermi GBM-230619: AstroSat CZTI non-detection and upper limits for the sub-threshold candidate
  68. LIGO/Virgo S230620ad: Global MASTER-Net observations report
  69. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): Kinder observations with Lulin observatory and a probable plateau in the g-band light curve
  70. LIGO/Virgo/KAGRA S230615az: Wendelstein observations of DESI galaxies and GIT candidates
  71. ZTF23aaoohpy/AT2023lcr: Liverpool Telescope detection
  72. GRB 230618A: Osservatorio Astronomico Nastro verde upper limit
  73. LIGO/Virgo S230619i: Global MASTER-Net observations report
  74. LIGO/Virgo S230618aq: Global MASTER-Net observations report
  75. LIGO/Virgo S230618y: Global MASTER-Net observations report
  76. LIGO/Virgo S230618s: Global MASTER-Net observations report
  77. LIGO/Virgo S230616aa: Global MASTER-Net observations report
  78. LIGO/Virgo S230615ak: Global MASTER-Net observations report
  79. LIGO/Virgo S230618k: Global MASTER-Net observations report
  80. LIGO/Virgo S230617bc: Global MASTER-Net observations report
  81. LIGO/Virgo S230617aq: Global MASTER-Net observations report
  82. LIGO/Virgo S230617aj: Global MASTER-Net observations report
  83. GRB 230616A: AstroSat CZTI detection
  84. LIGO/Virgo/KAGRA S230529ay: Upper limits from a two-week IceCube neutrino search
  85. LIGO/Virgo S230615be: Global MASTER-Net observations report
  86. LIGO/Virgo S230608aw: Global MASTER-Net observations report
  87. LIGO/Virgo S230609a: Global MASTER-Net observations report
  88. LIGO/Virgo S230608ah: Global MASTER-Net observations report
  89. GRB 230606A: Enhanced Swift-XRT position
  90. GRB 230606A: Swift detection of a burst
  91. GRB 230603A: Fermi GBM Final Real-time Localization
  92. LIGO/Virgo S230601bf: Global MASTER-Net observations report
  93. LIGO/Virgo/KAGRA S230529ay: Upper limits from CALET observations.
  94. LIGO/Virgo/KAGRA S230529ay: AstroSat CZTI non-detection and upper limits
  95. LIGO/Virgo S230529ay: Global MASTER-Net observations report
  96. LIGO/Virgo/KAGRA S230529ay: upper limits from AGILE/MCAL
  97. LIGO/Virgo/KAGRA S230529ay: Coverage and upper limits from MAXI/GSC observations
  98. LIGO/Virgo/KAGRA S230529ay: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  99. LIGO/Virgo/KAGRA S230529ay: Identification of a GW compact binary merger candidate
  100. LIGO/Virgo S230529p: Global MASTER-Net observations report

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