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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"

3043 results found.

  1. Swift GRB240101.85: Global MASTER-Net observations report
  2. Fermi trigger No 725806648: Global MASTER-Net observations report
  3. Fermi trigger No 725592555: Global MASTER-Net observations report
  4. Fermi trigger No 725143760: Global MASTER-Net observations report
  5. Fermi trigger No 724781422: Global MASTER-Net observations report
  6. GRB 231215A: AMI-LA radio detection
  7. GRB 231214A: Swift-BAT refined analysis
  8. GRB 231216A: BOOTES-2/TELMA optical upper limit
  9. GRB 231205B: VZLUSAT-2 detection
  10. GRB 231215A: GAD Observatory, La Spezia, Italy upper limit;
  11. GRB 231215A: Swift/UVOT Detection
  12. GRB 231210B: MeerLICHT afterglow observations
  13. IceCube Alert 231211.03: Global MASTER-Net observations report
  14. Fermi trigger No 723906955: Global MASTER-Net observations report
  15. IPN triangulation of GRB 231205A
  16. Fermi trigger No 723581802: Global MASTER-Net observations report
  17. GRB 231205B: Nanshan/HMT optical upper limit
  18. GRB 231205A: DDOTI Upper Limits on the Afterglow
  19. Fermi trigger No 723326169: Global MASTER-Net observations report
  20. LIGO/Virgo/KAGRA S231129ac: Upper limits from Swift/BAT-GUANO
  21. Fermi trigger No 723412808: Global MASTER-Net observations report
  22. GRB 231129A: Swift-BAT refined analysis
  23. Fermi trigger No 722653947: Global MASTER-Net observations report
  24. Fermi trigger No 722400249: Global MASTER-Net observations report
  25. GRB 231117A: GTC Near-Infrared Observations
  26. Konus-Wind detection of GRB 231020A
  27. GRB 231117A : MITSuME Akeno optical afterglow candidate detection
  28. Fermi trigger No 722039659: Global MASTER-Net observations report
  29. GRB 231115A : OHP/T120 optical upper limit
  30. GRB 231117A : MITSuME Akeno optical upper limits
  31. Fermi GRB 231115A: Global MASTER-Net observations report
  32. GRB 231113A (short): Glowbug gamma-ray detection
  33. Swift GRB231111.60: Global MASTER-Net observations report
  34. Fermi trigger No 721204446: Global MASTER-Net observations report
  35. Fermi GRB 231108A: Global MASTER-Net observations report
  36. Fermi GRB 231106A: Global MASTER-Net observations report
  37. GRB 231104A: NOT upper limit
  38. Fermi GRB 231103A: Global MASTER-Net observations report
  39. Swift GRB231104.07: Global MASTER-Net observations report
  40. GRB 231030B: AstroSat CZTI detection
  41. Fermi GRB 231030B: Global MASTER-Net observations report
  42. Fermi trigger No 720224759: Global MASTER-Net observations report
  43. LIGO/Virgo/KAGRA S231025t: Global MASTER-Net observations report
  44. LIGO/Virgo/KAGRA S231025a: Global MASTER-Net observations report
  45. GRB 231020A: AstroSat CZTI detection
  46. Fermi trigger No 719846439: Global MASTER-Net observations report
  47. LIGO/Virgo/KAGRA S231021az: Coverage and upper limits from MAXI/GSC observations
  48. GRB 231018A: Fermi GBM Detection
  49. LIGO/Virgo/KAGRA S230919bj: Identification of a GW compact binary merger candidate
  50. Fermi trigger No 716449174: Global MASTER-Net observations report
  51. GRB 230903A: Enhanced Swift-XRT position
  52. GRB 230903A: Swift-BAT refined analysis
  53. Fermi trigger No 715552087: Global MASTER-Net observations report
  54. GRB 230826A: Swift-BAT refined analysis
  55. AT 2023qxj: ZTF discovery of the likely afterglow of Fermi GRB 230827256
  56. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  57. Swift GRB230821.64: Global MASTER-Net observations report
  58. GRB 230818A: Tautenburg observations
  59. GRB 230818A: Leavitt Observatory upper limit
  60. GRB 230818A: SAO RAS Zeiss-1000 observations
  61. Fermi GRB 230818A: Global MASTER-Net observations report
  62. Fermi trigger No 713974668: Global MASTER-Net observations report
  63. Swift GRB230818.98: Global MASTER-Net observations report
  64. IPN triangulation of GRB 230815B
  65. GRB 230812B: continued SAO RAS optical observation
  66. GRB 230812B: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi GRB (Trigger 713559497)
  67. Fermi trigger No 713205976: Global MASTER-Net observations report
  68. Fermi GRB 230807A: Global MASTER-Net observations report
  69. Fermi trigger No 713134237: Global MASTER-Net observations report
  70. Fermi trigger No 712927418: Global MASTER-Net observations report
  71. Fermi trigger No 712798043: Global MASTER-Net observations report
  72. LIGO/Virgo/KAGRA S230802aq: Identification of a GW compact binary merger candidate
  73. GRB 230723B: Swift-BAT refined analysis
  74. IceCube-230727A: Upper limits from a search for additional neutrino events in IceCube
  75. IceCube-230724A: Upper limits from a search for additional neutrino events in IceCube
  76. IceCube Alert 230725.90: Global MASTER-Net observations report
  77. IceCube Alert 230724.08: Global MASTER-Net observations report
  78. Fermi trigger No 711805358: Global MASTER-Net observations report
  79. Swift GRB 230723B: Global MASTER-Net observations report
  80. Fermi GRB 230723A: Global MASTER-Net observations report
  81. IceCube-230707A: No candidates from the Zwicky Transient Facility
  82. LIGO/Virgo/KAGRA S230627c: GECKO optical follow-up observations of host galaxy candidates and ZTF23aaptsuy/AT2023lxu
  83. Fermi trigger No 710117592: Global MASTER-Net observations report
  84. Konus-Wind detection of GRB 220623A
  85. Fermi GRB 230628C: Global MASTER-Net observations report
  86. Fermi GRB 230628D: Global MASTER-Net observations report
  87. ZTF23aaoohpy /AT2023lcr: TNG NIR detection
  88. LIGO/Virgo S230621ad: Global MASTER-Net observations report
  89. LIGO/Virgo S230620ad: Global MASTER-Net observations report
  90. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Swift/UVOT detection
  91. IPN triangulation of GRB 230616A (short)
  92. AT2023lcr: Neil Gehrels Swift Observatory X-ray detection
  93. LIGO/Virgo S230620al: Global MASTER-Net observations report
  94. LIGO/Virgo S230618s: Global MASTER-Net observations report
  95. LIGO/Virgo S230616aa: Global MASTER-Net observations report
  96. LIGO/Virgo S230615ak: Global MASTER-Net observations report
  97. LIGO/Virgo S230617ba: Global MASTER-Net observations report
  98. LIGO/Virgo S230618k: Global MASTER-Net observations report
  99. LIGO/Virgo S230618d: Global MASTER-Net observations report
  100. LIGO/Virgo S230617bc: Global MASTER-Net observations report

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