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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"

5060 results found.

  1. GRB 240303B: Fermi GBM Final Localization
  2. IceCube-240229A: Upper limits from a search for additional neutrino events in IceCube
  3. GRB 240229A: DDOTI Upper Limits on the Afterglow
  4. GRB 240225B: further SAO RAS optical observations
  5. Fermi GRB 240229A: Global MASTER-Net observations report
  6. IceCube Alert 240229.66: Global MASTER-Net observations report
  7. GRB 240225B: Mondy afterglow observations
  8. Fermi GRB 240227A: Global MASTER-Net observations report
  9. GRB 240216A: GRBAlpha detection
  10. Fermi trigger No 729914426: Global MASTER-Net observations report
  11. GRB 240214A/1H 0451-560: MAXI/GSC detection
  12. GRB 240209A: GOTO optical counterpart candidate
  13. Fermi trigger No 729152364: Global MASTER-Net observations report
  14. Fermi trigger No 729012023: Global MASTER-Net observations report
  15. Fermi trigger No 728749569: Global MASTER-Net observations report
  16. IceCube-240204A: Upper limits from a search for additional neutrino events in IceCube
  17. GRB 240128A: MAXI/GSC detection
  18. GRB 240123A: further SAO RAS optical observations
  19. GRB 240123A: SAO RAS optical observations
  20. GRB 240123A: Mondy continued optical observations + correction of the GRB name in GCN 35605
  21. GRB 240123B: Fermi GBM Final Real-time Localization
  22. GRB 240122A: MAXI/GSC detection
  23. GRB 240115A: Fermi GBM Observation
  24. GRB 240115A: Swift/BAT-GUANO detection of a short burst
  25. Fermi GRB 240115A: Global MASTER-Net observations report
  26. GRB 240115A: Fermi GBM Final Real-time Localization
  27. GRB 240112C: SAO RAS optical observations
  28. GRB 231215A: radio detection with the VLA
  29. GRB 240107A: MAXI/GSC detection
  30. Fermi trigger No 726347794: Global MASTER-Net observations report
  31. GRB 240102C: AstroSat CZTI detection
  32. Fermi trigger No 725806648: Global MASTER-Net observations report
  33. GRB 231222B: GRBAlpha detection
  34. LIGO/Virgo/KAGRA S231223j: Identification of a GW compact binary merger candidate
  35. Fermi trigger No 724781422: Global MASTER-Net observations report
  36. Fermi trigger No 724278269: Global MASTER-Net observations report
  37. IceCube Alert 231211.03: Global MASTER-Net observations report
  38. Fermi trigger No 723581802: Global MASTER-Net observations report
  39. Fermi trigger No 723435916: Global MASTER-Net observations report
  40. Fermi trigger No 723326169: Global MASTER-Net observations report
  41. IceCube-231202A: Upper limits from a search for additional neutrino events in IceCube
  42. Fermi trigger No 723412808: Global MASTER-Net observations report
  43. GRB 231203A: Fermi GBM Observation
  44. GRB 231204A: Fermi GBM Final Real-time Localization
  45. Fermi trigger No 723279695: Global MASTER-Net observations report
  46. GRB 231129B: MAXI/GSC detection
  47. Fermi trigger No 722507896: Global MASTER-Net observations report
  48. Fermi trigger No 722462310: Global MASTER-Net observations report
  49. Fermi trigger No 722400249: Global MASTER-Net observations report
  50. GRB 231117A: CALET Gamma-Ray Burst Monitor detection
  51. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
  52. GRB 231117A: MAAO 0.7-m telescope optical upper limit
  53. GRB 231117A: GECAM-C detection
  54. GRB 231117A: GRBAlpha detection
  55. GRB 231117A: REM optical and NIR early-time observations
  56. GRB 231117A (short): Glowbug gamma-ray detection
  57. GRB 231117A: ATLAS non-detection of an optical counterpart
  58. Konus-Wind detection of GRB 231117A (short/hard)
  59. GRB 231115A: optical observations from INAF observatories
  60. GRB 231117A: AGILE detection of a bright short burst
  61. GRB 231117A: AstroSat CZTI detection of a bright short burst
  62. GRB 231117A: Swift detection of a bright short burst
  63. GRB231115A: Liverpool Telescope imaging
  64. GRB 231115A: archival HST observations
  65. Fermi GRB 231115A: Global MASTER-Net observations report
  66. GRB 231111A: GMG observation (correction)
  67. GRB 231111A: GMG observation upper limit
  68. LIGO/Virgo/KAGRA S231110g: Identification of a GW compact binary merger candidate
  69. IceCube-231103A: No candidates from the Zwicky Transient Facility
  70. Fermi trigger No 721204446: Global MASTER-Net observations report
  71. Fermi GRB 231108A: Global MASTER-Net observations report
  72. GRB 231108A: Fermi GBM Final Real-time Localization
  73. Fermi GRB 231106A: Global MASTER-Net observations report
  74. IceCube-231103A: Upper limits from a search for additional neutrino events in IceCube
  75. Fermi-LAT gamma-ray observations of IceCube-231103A
  76. Fermi GRB 231103A: Global MASTER-Net observations report
  77. GRB231104A: LCOGT Optical Upper Limits
  78. IceCube Alert 231103.39: Global MASTER-Net observations report
  79. IceCube-231103A - IceCube observation of a high-energy neutrino candidate track-like event
  80. GRB 231024A: GRANDMA observations of AT2023vuc/GOTO23baj candidate
  81. Fermi trigger No 720498201: Global MASTER-Net observations report
  82. Fermi GRB 231030B: Global MASTER-Net observations report
  83. LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
  84. Fermi trigger No 720224759: Global MASTER-Net observations report
  85. IceCube Alert 231027.18: Global MASTER-Net observations report
  86. LIGO/Virgo/KAGRA S231025t: Global MASTER-Net observations report
  87. LIGO/Virgo/KAGRA S231025a: Global MASTER-Net observations report
  88. LIGO/Virgo/KAGRA S231025a: two counterpart neutrino candidates from IceCube neutrino searches
  89. IceCube-231004A: Upper limits from a search for additional neutrino events in IceCube
  90. IceCube-231004A: No significant detection in HAWC
  91. GRB 231003A is not a GRB
  92. LIGO/Virgo/KAGRA S230922g: DECam GW-MMADS candidates
  93. LIGO/Virgo/KAGRA S230922g: Identification of a GW compact binary merger candidate
  94. Fermi GBM Statement for Trigger 716527670/230916144
  95. AT2023sva: redshift from OSIRIS+/GTC of the ZTF afterglow
  96. ZTF and SEDM Observations of the Candidate Optical Afterglow AT 2023sva
  97. GRB 230911A: Fermi GBM Observation
  98. Swift GRB230916.13: Global MASTER-Net observations report
  99. GRB 230911A: Swift-XRT afterglow detection
  100. Fermi trigger No 716449174: Global MASTER-Net observations report

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