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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

36332 results found.

  1. GRB 230622A: Swift-XRT refined Analysis
  2. GRB 230623A: MAXI/GSC detection
  3. Swift GRB 230622A: Global MASTER-Net observations report
  4. Fermi GBM-230619: AstroSat CZTI non-detection and upper limits for the sub-threshold candidate
  5. GRB 230622A: Swift detection of a burst
  6. GRB 230621A: Fermi GBM Final Localization Correction
  7. Fermi GBM-230619: A soft subthreshold candidate potentially associated with a subthreshold LIGO/Virgo compact binary merger candidate
  8. ZTF23aaoohpy/AT2023lcr: Montarrenti Observatory optical observations
  9. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Upper limits from Konus-Wind observations
  10. ZTF23aaoohpy/AT2023lc: Mondy optical observations
  11. IPN triangulation of GRB 230616A (short)
  12. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): Kinder observations with Lulin observatory and a probable plateau in the g-band light curve
  13. ZTF23aaoohpy/AT2023lcr: Keck/LRIS spectroscopy and redshift
  14. ZTF23aaoohpy/AT2023lcr: Liverpool Telescope detection
  15. GRB 230618A: Osservatorio Astronomico Nastro verde upper limit
  16. GRB 230618A: Enhanced Swift-XRT position
  17. GRB 230618A: Swift/UVOT Upper Limits
  18. GRB 230618A: Swift-XRT refined Analysis
  19. GRB 230616A: Swift-XRT observations
  20. GRB 230618A: KAIT Optical Observations
  21. Swift GRB 230618A: Global MASTER-Net observations report
  22. GRB230618A: LCOGT Optical Observations
  23. GRB 230618B: Fermi GBM Final Real-time Localization
  24. GRB 230618A: Prompt enhanced Swift-XRT position
  25. GRB 230618A: Swift detection of a burst
  26. GRB 230616A: Swift ToO observations
  27. GRB 230617A: Fermi GBM Final Real-time Localization
  28. GRB 230614C: GRBAlpha detection
  29. GRB 230616A: AstroSat CZTI detection
  30. GRB 230616A: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  31. GRB 230614C: AstroSat CZTI detection
  32. GRB 230614B: Fermi GBM Observation
  33. GRB 230614C: Fermi GBM Detection
  34. GRB 230614B: Swift/BAT-GUANO detection outside the coded FOV
  35. GRB 230614B: Fermi GBM Final Real-time Localization
  36. GRB 230614A: Fermi GBM Final Real-time Localization
  37. GRB 230606A: LCOGT Optical Observations
  38. GRB 230608A: CALET Gamma-Ray Burst Monitor detection
  39. GRB 230608A: AstroSat CZTI detection
  40. GRB 230608A: AGILE detection
  41. Fermi GRB 230603A: Global MASTER-Net observations report
  42. GRB 230506B: Chandra localization of the X-ray afterglow
  43. GRB 230606A: Swift-BAT refined analysis
  44. GRB 230606A: Gaoyazi/GOT optical upper limit
  45. GRB 230606A: Fermi GBM Observation
  46. GRB 230606A: BOOTES-5/JGT optical upper limit
  47. GRB 230606A: Swift-XRT refined Analysis
  48. GRB 230604A: GRBAlpha detection
  49. GRB 230606A: Swift/UVOT Upper Limits
  50. GRB 230606A: Enhanced Swift-XRT position
  51. GRB 230606A: Swift detection of a burst
  52. IceCube-230603A: Upper limits from a search for additional neutrino events in IceCube
  53. GRB 230604A: AstroSat CZTI detection of a short GRB
  54. GRB 230603A: Fermi GBM Final Real-time Localization
  55. GRB 230521A: VZLUSAT-2 detection
  56. GRB 230522A: GRBAlpha and VZLUSAT-2 joint detection
  57. GRB 230525A: CALET Gamma-Ray Burst Monitor detection
  58. LIGO/Virgo/KAGRA S230529ay: Upper limits from Fermi-GBM Observations
  59. LIGO/Virgo/KAGRA S230529ay: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  60. GRB 230529A: Fermi GBM Final Real-time Localization
  61. LIGO/Virgo/KAGRA S230518h: Upper limits from Glowbug gamma-ray observations
  62. GRB 230510A: Swift-BAT refined analysis
  63. GRB 230525A: Fermi GBM Detection
  64. GRB 230525A: Fermi GBM Final Localization
  65. GRB 230523B: GRBAlpha detection
  66. GRB 230524A: Fermi GBM Observation
  67. GRB 230524B: AstroSat CZTI detection
  68. GRB 230524A: AstroSat CZTI detection
  69. GRB 230524A: AGILE detection
  70. GRB 230524A: Fermi GBM Final Real-time Localization
  71. GRB 230523B: Name correction from GCN Circular 33859
  72. GRB 230523A: Swift/BAT-GUANO detection of a short hard burst
  73. Fermi Gamma-ray Burst Monitor trigger 706536788/230523509 is not a GRB
  74. GRB 230523A: Fermi GBM Final Real-time Localization
  75. GRB 230518B: VZLUSAT-2 detection
  76. Fermi Gamma-ray Burst Monitor trigger 706338208/230521211 is not a GRB
  77. IPN triangulation of GRB 230518A (short)
  78. GRB 230520A: CALET Gamma-Ray Burst Monitor detection
  79. GRB 230521A: Fermi GBM Final Real-time Localization
  80. GRB 230520B is not a GRB
  81. GRB 230520B: Fermi GBM Final Real-time Localization
  82. GRB 230520A: MAXI/GSC detection
  83. GRB 230518A: Fermi GBM Observation
  84. LIGO/Virgo/KAGRA S230518h: Upper limits from Konus-Wind observations
  85. GRB 230518A: Swift/BAT-GUANO detection
  86. GRB 230518A: Fermi GBM Final Real-time Localization
  87. Fermi Gamma-ray Burst Monitor trigger 706068974/230518095 is not a GRB
  88. LIGO/Virgo/KAGRA S230518h: Upper limits from Fermi-GBM Observations
  89. LIGO/Virgo S230518h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  90. GRB 230513A: Zwicky Transient Facility continuous observations of a Fermi Short GRB (Trigger 705709044)
  91. GRB 230510B: GRBAlpha detection
  92. GRB 230517A: BALROG localization (Fermi Trigger 706014351 / GRB 230517462)
  93. Improved IPN triangulation of GRB 230512A
  94. GRB 230517A: Fermi GBM Final Real-time Localization
  95. GRB 230510B: Fermi GBM detection
  96. GRB 230516A: Fermi GBM Final Real-time Localization
  97. IPN triangulation of GRB 230511D (short)
  98. IPN triangulation of GRB 230512A
  99. GRB 230513A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
  100. GRB 230512A: Nanshan/NEXT non-detection of GRB afterglow candidate

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