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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"

3040 results found.

  1. Fermi trigger No 725143760: Global MASTER-Net observations report
  2. Fermi trigger No 724781422: Global MASTER-Net observations report
  3. GRB 231215A: AMI-LA radio detection
  4. GRB 231214A: Swift-BAT refined analysis
  5. GRB 231216A: BOOTES-2/TELMA optical upper limit
  6. GRB 231205B: VZLUSAT-2 detection
  7. GRB 231215A: GAD Observatory, La Spezia, Italy upper limit;
  8. GRB 231215A: Swift/UVOT Detection
  9. GRB 231210B: MeerLICHT afterglow observations
  10. IceCube Alert 231211.03: Global MASTER-Net observations report
  11. Fermi trigger No 723906955: Global MASTER-Net observations report
  12. IPN triangulation of GRB 231205A
  13. Fermi trigger No 723581802: Global MASTER-Net observations report
  14. GRB 231205B: Nanshan/HMT optical upper limit
  15. GRB 231205A: DDOTI Upper Limits on the Afterglow
  16. Fermi trigger No 723326169: Global MASTER-Net observations report
  17. LIGO/Virgo/KAGRA S231129ac: Upper limits from Swift/BAT-GUANO
  18. Fermi trigger No 723412808: Global MASTER-Net observations report
  19. GRB 231129A: Swift-BAT refined analysis
  20. Fermi trigger No 722653947: Global MASTER-Net observations report
  21. Fermi trigger No 722400249: Global MASTER-Net observations report
  22. GRB 231117A: GTC Near-Infrared Observations
  23. Konus-Wind detection of GRB 231020A
  24. GRB 231117A : MITSuME Akeno optical afterglow candidate detection
  25. Fermi trigger No 722039659: Global MASTER-Net observations report
  26. GRB 231115A : OHP/T120 optical upper limit
  27. GRB 231117A : MITSuME Akeno optical upper limits
  28. Fermi GRB 231115A: Global MASTER-Net observations report
  29. GRB 231113A (short): Glowbug gamma-ray detection
  30. Swift GRB231111.60: Global MASTER-Net observations report
  31. Fermi trigger No 721204446: Global MASTER-Net observations report
  32. Fermi GRB 231108A: Global MASTER-Net observations report
  33. Fermi GRB 231106A: Global MASTER-Net observations report
  34. GRB 231104A: NOT upper limit
  35. Fermi GRB 231103A: Global MASTER-Net observations report
  36. Swift GRB231104.07: Global MASTER-Net observations report
  37. GRB 231030B: AstroSat CZTI detection
  38. Fermi GRB 231030B: Global MASTER-Net observations report
  39. Fermi trigger No 720224759: Global MASTER-Net observations report
  40. LIGO/Virgo/KAGRA S231025t: Global MASTER-Net observations report
  41. LIGO/Virgo/KAGRA S231025a: Global MASTER-Net observations report
  42. GRB 231020A: AstroSat CZTI detection
  43. Fermi trigger No 719846439: Global MASTER-Net observations report
  44. LIGO/Virgo/KAGRA S231021az: Coverage and upper limits from MAXI/GSC observations
  45. GRB 231018A: Fermi GBM Detection
  46. LIGO/Virgo/KAGRA S230919bj: Identification of a GW compact binary merger candidate
  47. Fermi trigger No 716449174: Global MASTER-Net observations report
  48. GRB 230903A: Enhanced Swift-XRT position
  49. GRB 230903A: Swift-BAT refined analysis
  50. Fermi trigger No 715552087: Global MASTER-Net observations report
  51. GRB 230826A: Swift-BAT refined analysis
  52. AT 2023qxj: ZTF discovery of the likely afterglow of Fermi GRB 230827256
  53. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  54. Swift GRB230821.64: Global MASTER-Net observations report
  55. GRB 230818A: Tautenburg observations
  56. GRB 230818A: Leavitt Observatory upper limit
  57. GRB 230818A: SAO RAS Zeiss-1000 observations
  58. Fermi GRB 230818A: Global MASTER-Net observations report
  59. Fermi trigger No 713974668: Global MASTER-Net observations report
  60. Swift GRB230818.98: Global MASTER-Net observations report
  61. IPN triangulation of GRB 230815B
  62. GRB 230812B: continued SAO RAS optical observation
  63. GRB 230812B: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi GRB (Trigger 713559497)
  64. Fermi trigger No 713205976: Global MASTER-Net observations report
  65. Fermi GRB 230807A: Global MASTER-Net observations report
  66. Fermi trigger No 713134237: Global MASTER-Net observations report
  67. Fermi trigger No 712927418: Global MASTER-Net observations report
  68. Fermi trigger No 712798043: Global MASTER-Net observations report
  69. LIGO/Virgo/KAGRA S230802aq: Identification of a GW compact binary merger candidate
  70. GRB 230723B: Swift-BAT refined analysis
  71. IceCube-230727A: Upper limits from a search for additional neutrino events in IceCube
  72. IceCube-230724A: Upper limits from a search for additional neutrino events in IceCube
  73. IceCube Alert 230725.90: Global MASTER-Net observations report
  74. IceCube Alert 230724.08: Global MASTER-Net observations report
  75. Fermi trigger No 711805358: Global MASTER-Net observations report
  76. Swift GRB 230723B: Global MASTER-Net observations report
  77. Fermi GRB 230723A: Global MASTER-Net observations report
  78. IceCube-230707A: No candidates from the Zwicky Transient Facility
  79. LIGO/Virgo/KAGRA S230627c: GECKO optical follow-up observations of host galaxy candidates and ZTF23aaptsuy/AT2023lxu
  80. Fermi trigger No 710117592: Global MASTER-Net observations report
  81. Konus-Wind detection of GRB 220623A
  82. Fermi GRB 230628C: Global MASTER-Net observations report
  83. Fermi GRB 230628D: Global MASTER-Net observations report
  84. ZTF23aaoohpy /AT2023lcr: TNG NIR detection
  85. LIGO/Virgo S230621ad: Global MASTER-Net observations report
  86. LIGO/Virgo S230620ad: Global MASTER-Net observations report
  87. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Swift/UVOT detection
  88. IPN triangulation of GRB 230616A (short)
  89. AT2023lcr: Neil Gehrels Swift Observatory X-ray detection
  90. LIGO/Virgo S230620al: Global MASTER-Net observations report
  91. LIGO/Virgo S230618s: Global MASTER-Net observations report
  92. LIGO/Virgo S230616aa: Global MASTER-Net observations report
  93. LIGO/Virgo S230615ak: Global MASTER-Net observations report
  94. LIGO/Virgo S230617ba: Global MASTER-Net observations report
  95. LIGO/Virgo S230618k: Global MASTER-Net observations report
  96. LIGO/Virgo S230618d: Global MASTER-Net observations report
  97. LIGO/Virgo S230617bc: Global MASTER-Net observations report
  98. LIGO/Virgo S230617aq: Global MASTER-Net observations report
  99. LIGO/Virgo S230617aj: Global MASTER-Net observations report
  100. LIGO/Virgo S230616s: Global MASTER-Net observations report

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