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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').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

3759 results found.

  1. GRB 231110A: Terskol Zeiss-2000 optical upper limit
  2. Swift GRB231110.89: Global MASTER-Net observations report
  3. Fermi GRB 231108A: Global MASTER-Net observations report
  4. Fermi trigger No 721006392: Global MASTER-Net observations report
  5. Fermi GRB 231106A: Global MASTER-Net observations report
  6. Fermi GRB 231103A: Global MASTER-Net observations report
  7. GRB 231104A: Fermi-LAT detection
  8. GRB 231104A: Swift detection of a bright burst
  9. GRB 231104A: Fermi GBM Final Real-time Localization
  10. Fermi trigger No 720498201: Global MASTER-Net observations report
  11. GRB 231028B: VZLUSAT-2 detection
  12. Fermi GRB 231030B: Global MASTER-Net observations report
  13. IceCube-231027A: Upper limits from a search for additional neutrino events in IceCube
  14. GRB 231028A: CALET Gamma-Ray Burst Monitor detection
  15. LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
  16. GRB 231028A: AstroSat CZTI detection
  17. GRB 231028A: Glowbug gamma-ray detection
  18. GRB 231028A: Fermi GBM Detection
  19. Fermi trigger No 720224759: Global MASTER-Net observations report
  20. Swift GRB 231028A: Global MASTER-Net observations report
  21. LIGO/Virgo/KAGRA S231028bg: Identification of a GW compact binary merger candidate
  22. GRB 231028A: Fermi GBM Final Real-time Localization
  23. IceCube Alert 231027.18: Global MASTER-Net observations report
  24. LIGO/Virgo/KAGRA S231025t: Global MASTER-Net observations report
  25. LIGO/Virgo/KAGRA S231025a: Global MASTER-Net observations report
  26. Fermi trigger No 719846439: Global MASTER-Net observations report
  27. Fermi GRB 231019A: Global MASTER-Net observations report
  28. Konus-Wind detection of GRB 231018A
  29. IPN triangulation of GRB 231018A
  30. GRB 231018A: GROWTH-India Follow-Up of a Fermi Long GRB
  31. IceCube-231004A: No significant detection in HAWC
  32. LIGO/Virgo/KAGRA S231005j: Identification of a GW compact binary merger candidate
  33. NuEm-230927A: Swift-XRT follow-up
  34. LIGO/Virgo/KAGRA S230928cb: Identification of a GW compact binary merger candidate
  35. LIGO/Virgo/KAGRA S230922g: DECam GW-MMADS candidates
  36. IPN triangulation of GRB 230919A (short)
  37. GRB 230916A: NuSTAR Discovery of Prompt Emission from a Potential GRB
  38. Fermi trigger No 716449174: Global MASTER-Net observations report
  39. Fermi trigger No 716145795: Global MASTER-Net observations report
  40. GRB 230205A: LBT spectroscopy of two host galaxy candidates
  41. Fermi GRB 230906A: Global MASTER-Net observations report
  42. GRB 230904C: Fermi GBM Final Localization
  43. Fermi trigger No 715429986: Global MASTER-Net observations report
  44. Fermi GRB 230903A: Global MASTER-Net observations report
  45. GRB 230828A: AstroSat CZTI detection
  46. GRB 230828A: GRBAlpha detection
  47. GRB 230827B / GRB 230827256: Fermi GBM Observation
  48. Fermi GRB 230827A: Global MASTER-Net observations report
  49. AT 2023qxj: ZTF discovery of the likely afterglow of Fermi GRB 230827256
  50. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  51. Integral GRB230824.72: Global MASTER-Net observations report
  52. Swift GRB230821.64: Global MASTER-Net observations report
  53. Swift Triggers 1186280 and 1186291 are not GRBs
  54. GRB 230818A: SAO RAS 6-m telescope spectroscopy
  55. Fermi GRB 230818A: Global MASTER-Net observations report
  56. Swift GRB230818.98: Global MASTER-Net observations report
  57. Swift GRB230818.98: Global MASTER-Net OT detection
  58. Swift GRB230816.80: Global MASTER-Net observations report
  59. LAT GRB230812.79: Global MASTER-Net observations report
  60. Fermi trigger No 713525317: Global MASTER-Net observations report
  61. GRB 230812A: Fermi GBM Final Real-time Localization
  62. GRB 230805B : MITSuME Akeno optical upper limits
  63. transient SPT-SVJ025406.5-702837: ATCA follow-up observations
  64. Fermi trigger No 713134237: Global MASTER-Net observations report
  65. GRB 230803A: AstroSat CZTI detection
  66. IceCube-230724A: JCMT/SCUBA-2 submm observations
  67. IceCube-230707A: JCMT/SCUBA-2 submm observations
  68. GRB 230723A: Detection of candidate millimeter-band radiation by SPT-3G
  69. Fermi trigger No 712306969: Global MASTER-Net observations report
  70. IceCube-230727A: No candidates from the Zwicky Transient Facility
  71. IceCube-230727A: Upper limits from a search for additional neutrino events in IceCube
  72. GRB 230728A: BOOTES-1 optical upper limit
  73. GRB 230728A: Fermi GBM Observation
  74. GRB 230728A: LCOGT Optical Upper Limit
  75. GRB 230728A: NOT optical observations and possible host galaxy
  76. Swift GRB230728.12: Global MASTER-Net observations report
  77. Fermi GRB 230723A: Global MASTER-Net observations report
  78. IPN triangulation of GRB 230715D
  79. GRB 230709C: Fermi GBM Final Localization
  80. IceCube Alert 230707.71: Global MASTER-Net observations report
  81. LIGO/Virgo/KAGRA S230707ai: Identification of a GW compact binary merger candidate
  82. LIGO/Virgo/KAGRA low-significance gravitational wave candidate S230701z: one counterpart neutrino candidate from IceCube neutrino searches
  83. IPN triangulation of GRB 230625B (ultra-long)
  84. GRB 230625B: CALET Gamma-Ray Burst Monitor detection
  85. GRB 230625B: AstroSat CZTI detection
  86. Fermi GRB 230628D: Global MASTER-Net observations report
  87. LIGO/Virgo/KAGRA S230628ax: Identification of a GW compact binary merger candidate
  88. GRB 230628E: LCOGT Optical Upper Limit
  89. Swift GRB230628.93: Global MASTER-Net observations report
  90. GRB 230628D: BALROG localization (Fermi Trigger 709676556 / GRB 230628849)
  91. GRB 230628D: Fermi GBM Final Real-time Localization
  92. LIGO/Virgo/KAGRA low-significance gravitational wave candidate S230628aj: one counterpart neutrino candidate from IceCube neutrino searches
  93. GRB 230628C: Fermi GBM Final Real-time Localization
  94. GRB 230628A: Fermi GBM Final Localization
  95. LIGO/Virgo/KAGRA S230527c: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  96. GRB 230625B: Swift/BAT-GUANO detection of a long burst
  97. INTEGRAL upper limit on any GRB associated with ZTF23aaoohpy/AT2023lcr
  98. ATLAS23msn/ZTF23aaoohpy/AT2023lcr: Zeiss-1000 of Koshka observatory optical observations
  99. LIGO/Virgo S230620ad: Global MASTER-Net observations report
  100. LIGO/Virgo S230620au: Global MASTER-Net observations report

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