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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').

3086 results found.

  1. Fermi trigger No 719846439: Global MASTER-Net observations report
  2. LIGO/Virgo/KAGRA S231021az: Coverage and upper limits from MAXI/GSC observations
  3. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  4. GRB 231018A: Fermi GBM Detection
  5. LIGO/Virgo/KAGRA S230917af: GRAWITA wide-field observations
  6. LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
  7. LIGO/Virgo/KAGRA S230919bj: Identification of a GW compact binary merger candidate
  8. LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
  9. LIGO/Virgo/KAGRA S230917af: MAXI/GSC observations
  10. Fermi trigger No 716449174: Global MASTER-Net observations report
  11. GRB 230903A: Enhanced Swift-XRT position
  12. GRB 230903A: Swift-BAT refined analysis
  13. Fermi trigger No 715552087: Global MASTER-Net observations report
  14. GRB 230826A: Swift-BAT refined analysis
  15. AT 2023qxj: ZTF discovery of the likely afterglow of Fermi GRB 230827256
  16. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  17. Trigger 1187142: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  18. MAXI/GSC detection of Swift J1727.8-1613 (GRB 230824A)
  19. Swift GRB230821.64: Global MASTER-Net observations report
  20. GRB 230818A: Tautenburg observations
  21. GRB 230818A: Leavitt Observatory upper limit
  22. GRB 230818A: SAO RAS Zeiss-1000 observations
  23. Fermi GRB 230818A: Global MASTER-Net observations report
  24. Fermi trigger No 713974668: Global MASTER-Net observations report
  25. Swift GRB230818.98: Global MASTER-Net observations report
  26. IPN triangulation of GRB 230815B
  27. GRB 230812B: continued SAO RAS optical observation
  28. GRB 230812B: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi GRB (Trigger 713559497)
  29. Fermi trigger No 713205976: Global MASTER-Net observations report
  30. Fermi GRB 230807A: Global MASTER-Net observations report
  31. Fermi trigger No 713134237: Global MASTER-Net observations report
  32. Fermi trigger No 712927418: Global MASTER-Net observations report
  33. Fermi trigger No 712798043: Global MASTER-Net observations report
  34. LIGO/Virgo/KAGRA S230802aq: Coverage and upper limits from MAXI/GSC observations
  35. LIGO/Virgo/KAGRA S230802aq: Identification of a GW compact binary merger candidate
  36. LIGO/Virgo/KAGRA S230731an: Coverage and upper limits from MAXI/GSC observations
  37. GRB 230723B: Swift-BAT refined analysis
  38. IceCube-230727A: Upper limits from a search for additional neutrino events in IceCube
  39. IceCube-230724A: Upper limits from a search for additional neutrino events in IceCube
  40. IceCube Alert 230725.90: Global MASTER-Net observations report
  41. IceCube Alert 230724.08: Global MASTER-Net observations report
  42. Fermi trigger No 711805358: Global MASTER-Net observations report
  43. Swift GRB 230723B: Global MASTER-Net observations report
  44. Fermi GRB 230723A: Global MASTER-Net observations report
  45. IceCube-230707A : MAXI upper limit and NICER follow-up observation of Swift J1753.5-0127
  46. IceCube-230707A: No candidates from the Zwicky Transient Facility
  47. LIGO/Virgo/KAGRA S230627c: GECKO optical follow-up observations of host galaxy candidates and ZTF23aaptsuy/AT2023lxu
  48. Fermi trigger No 710117592: Global MASTER-Net observations report
  49. Konus-Wind detection of GRB 220623A
  50. Fermi GRB 230628C: Global MASTER-Net observations report
  51. Fermi GRB 230628D: Global MASTER-Net observations report
  52. ZTF23aaoohpy /AT2023lcr: TNG NIR detection
  53. LIGO/Virgo/KAGRA S230627c: Coverage and upper limits from MAXI/GSC observations
  54. GRB 230623A: Swift-XRT observations
  55. GRB 230623A: Tiled Swift observations
  56. MAXI GRB 230623A: MASTER optical observations
  57. GRB 230623A: Tiled Swift observations
  58. GRB 230623A: MAXI/GSC detection
  59. LIGO/Virgo S230621ad: Global MASTER-Net observations report
  60. LIGO/Virgo S230620ad: Global MASTER-Net observations report
  61. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Swift/UVOT detection
  62. IPN triangulation of GRB 230616A (short)
  63. AT2023lcr: Neil Gehrels Swift Observatory X-ray detection
  64. LIGO/Virgo S230620al: Global MASTER-Net observations report
  65. LIGO/Virgo S230618s: Global MASTER-Net observations report
  66. LIGO/Virgo S230616aa: Global MASTER-Net observations report
  67. LIGO/Virgo S230615ak: Global MASTER-Net observations report
  68. LIGO/Virgo S230617ba: Global MASTER-Net observations report
  69. LIGO/Virgo S230618k: Global MASTER-Net observations report
  70. LIGO/Virgo S230618d: Global MASTER-Net observations report
  71. LIGO/Virgo S230617bc: Global MASTER-Net observations report
  72. LIGO/Virgo S230617aq: Global MASTER-Net observations report
  73. LIGO/Virgo S230617aj: Global MASTER-Net observations report
  74. LIGO/Virgo S230616s: Global MASTER-Net observations report
  75. LIGO/Virgo S230608as: Global MASTER-Net observations report
  76. LIGO/Virgo S230609a: Global MASTER-Net observations report
  77. LIGO/Virgo S230608ah: Global MASTER-Net observations report
  78. LIGO/Virgo S230529ay: Global MASTER-Net observations report
  79. LIGO/Virgo/KAGRA S230529ay: Coverage and upper limits from MAXI/GSC observations
  80. LIGO/Virgo/KAGRA S230529ay: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  81. LIGO/Virgo S230525a: Global MASTER-Net observations report
  82. LIGO/Virgo/KAGRA S230518h: Updated Sky localization
  83. IceCube Alert 230524.47: Global MASTER-Net observations report
  84. Fermi trigger No 706610076: Global MASTER-Net observations report
  85. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230523A
  86. LIGO/Virgo S230522a: Global MASTER-Net observations report
  87. LIGO/Virgo S230520ae: Global MASTER-Net observations report
  88. GRB 230520A: CALET Gamma-Ray Burst Monitor detection
  89. LIGO/Virgo/KAGRA S230520ae: Upper limits from IceCube neutrino search
  90. LIGO/Virgo/KAGRA S230518h: GECKO tiling observations with KMTNet
  91. GRB 230520A: MAXI/GSC detection
  92. LIGO/Virgo/KAGRA S230518h: Coverage and upper limits from MAXI/GSC observations
  93. LIGO/Virgo S230518h: Global MASTER-Net observations report
  94. LIGO/Virgo S230518h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  95. GRB 230510B: Fermi GBM detection
  96. GRB 230510B: AstroSat CZTI detection
  97. GRB 230510B: CALET Gamma-Ray Burst Monitor detection
  98. GRB 230510B: MAXI/GSC detection
  99. GRB 230506C: TSHAO possible afterglow candidate
  100. GRB 230420A: Swift-BAT refined analysis

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