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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"

35953 results found.

  1. Swift Trigger 1180055 is not a GRB
  2. GRB 230718A: Final Localization Correction
  3. GRB 230718A: Fermi GBM Final Real-time Localization
  4. Fermi Gamma-ray Burst Monitor trigger 711329677/230717982 is not a GRB
  5. IPN triangulation of GRB 230712C (short)
  6. IPN triangulation of GRB 230712A (short)
  7. GRB 230717A: Fermi GBM Final Real-time Localization
  8. GRB 230715A: Fermi GBM Final Real-time Localization
  9. Fermi GRB 230713A: Global MASTER-Net observations report
  10. GRB 230713A: Fermi GBM Final Real-time Localization
  11. GRB 230709B: CALET Gamma-Ray Burst Monitor detection
  12. GRB 230703A: CALET Gamma-Ray Burst Monitor detection
  13. GRB 230709C: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  14. IceCube-230708A: Upper limits from Swift/BAT-GUANO
  15. GRB 230712B: Fermi GBM Final Localization
  16. GRB 230707A: Swift/BAT-GUANO position correction
  17. GRB 230712A: Fermi GBM Final Real-time Localization
  18. GRB 230709C: GRBAlpha detection
  19. GRB 230709B: GRBAlpha detection
  20. GRB 230709C: Fermi GBM Detection
  21. GRB 230709C: Fermi GBM Final Localization
  22. GRB 230707B: Fermi GBM Observation
  23. GRB 230710A: Fermi GBM Final Real-time Localization
  24. GRB 230709C: AstroSat CZTI detection
  25. GRB 230707B: CALET Gamma-Ray Burst Monitor detection
  26. GRB 230703A detected with multiple GRID detectors
  27. GRB 230709C: BALROG localization (Fermi Trigger 710617111 / GRB 230709735)
  28. GRB 230709B: BALROG localization (Fermi Trigger 710614579 / GRB 230709706)
  29. Swift Trigger 1178410: possible GRB 230709A
  30. GRB 230628C: GRID Detection
  31. GRB 230707B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  32. GRB 230707A: Swift-XRT observations
  33. GRB 230707B: Fermi GBM Final Real-time Localization
  34. GRB 230707A: Fermi GBM Detection
  35. GRB 230707A: Swift ToO observations
  36. GRB 230707A: Swift/BAT-GUANO arcminute localization of a burst
  37. Fermi GRB 230707A: Global MASTER-Net observations report
  38. GRB 230707A: Fermi GBM Final Real-time Localization
  39. IBAS trigger number 10311: not a real GRB
  40. GRB 230625A: Detection by GRID
  41. GRB 230626A: VZLUSAT-2 detection
  42. GRB 230328B: LBT detection of the likely host galaxy
  43. Konus-Wind detection of GRB 220623A
  44. GRB 230701B: AstroSat CZTI detection
  45. GRB 230628E: Swift/UVOT Detection
  46. GRB 230628E: Swift-BAT refined analysis
  47. GRB 230702A: Fermi GBM Final Real-time Localization
  48. GRB 230628E: ATCA rapid radio follow-up
  49. GRB 230701A: Fermi GBM Final Real-time Localization
  50. LIGO/Virgo/KAGRA S230627c: Upper limits from Swift/BAT-GUANO
  51. IPN triangulation of GRB 230625B (ultra-long)
  52. GRB 230625B: CALET Gamma-Ray Burst Monitor detection
  53. GRB 230628E - VLT spectroscopic observations
  54. Fermi GRB 230628C: Global MASTER-Net observations report
  55. GRB 230625B: AstroSat CZTI detection
  56. GRB230628E: VLT optical identification of afterglow candidate
  57. GRB 230628E: Swift-XRT refined Analysis
  58. GRB 230628E: Enhanced Swift-XRT position (Correction to name in GCN 34115)
  59. GRB 230628A: Enhanced Swift-XRT position
  60. Fermi GRB 230628D: Global MASTER-Net observations report
  61. GRB 230628E: LCOGT Optical Upper Limit
  62. GRB 230628E: Swift detection of a burst
  63. GRB 230628D: BALROG localization (Fermi Trigger 709676556 / GRB 230628849)
  64. GRB 230628D: Fermi GBM Final Real-time Localization
  65. GRB 230628C: Fermi GBM Final Real-time Localization
  66. GRB 230628B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  67. GRB 230623B: CALET Gamma-Ray Burst Monitor detection
  68. GRB 230628A: Fermi GBM Final Localization
  69. GRB 230626A: GRBAlpha detection
  70. LIGO/Virgo/KAGRA S230527c: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  71. LIGO/Virgo/KAGRA S230627c: Upper limits from Fermi-GBM Observations
  72. GRB230626A: Fermi GBM Detection
  73. Konus-Wind detection of GRB 230616A
  74. GRB 230618A: Swift-BAT refined analysis
  75. GRB 230625B: Swift/BAT-GUANO detection of a long burst
  76. GRB 230622A: Swift-BAT refined analysis
  77. GRB 230623A: Swift-XRT observations
  78. GRB 230625A: Fermi GBM Final Real-time Localization
  79. INTEGRAL upper limit on any GRB associated with ZTF23aaoohpy/AT2023lcr
  80. ATLAS23msn/ZTF23aaoohpy/AT2023lcr: Zeiss-1000 of Koshka observatory optical observations
  81. GRB 230623B: Swift/BAT-GUANO detection of a long burst outside the coded FOV 
  82. GRB 230623A: Tiled Swift observations
  83. MAXI GRB 230623A: MASTER optical observations
  84. GRB 230623A: Tiled Swift observations
  85. GRB 230622A: ATCA rapid radio follow-up
  86. GRB 230622A: Swift-XRT refined Analysis
  87. GRB 230623A: MAXI/GSC detection
  88. Swift GRB 230622A: Global MASTER-Net observations report
  89. Fermi GBM-230619: AstroSat CZTI non-detection and upper limits for the sub-threshold candidate
  90. GRB 230622A: Swift detection of a burst
  91. GRB 230621A: Fermi GBM Final Localization Correction
  92. Fermi GBM-230619: A soft subthreshold candidate potentially associated with a subthreshold LIGO/Virgo compact binary merger candidate
  93. ZTF23aaoohpy/AT2023lcr: Montarrenti Observatory optical observations
  94. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Upper limits from Konus-Wind observations
  95. ZTF23aaoohpy/AT2023lc: Mondy optical observations
  96. IPN triangulation of GRB 230616A (short)
  97. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): Kinder observations with Lulin observatory and a probable plateau in the g-band light curve
  98. ZTF23aaoohpy/AT2023lcr: Keck/LRIS spectroscopy and redshift
  99. ZTF23aaoohpy/AT2023lcr: Liverpool Telescope detection
  100. GRB 230618A: Osservatorio Astronomico Nastro verde upper limit

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