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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

42477 results found.

  1. GRB 251001B: Fermi GBM Final Real-time Localization
  2. GRB 251001A: Fermi GBM Detection
  3. GRB 250910A / EP250910a: VLT limits on the possible associated supernova
  4. GRB 251001A: BALROG localization (Fermi Trigger 780979261 / GRB 251001112)
  5. GRB 251001A: Fermi GBM Final Real-time Localization
  6. LIGO/Virgo/KAGRA S250830bp: SOAR spectroscopy of two DESGW candidates
  7. LIGO/Virgo/KAGRA S250818k: further MeerKAT monitoring
  8. GRB 250910A / EP250910a: VLT/X-shooter host galaxy redshift z = 0.592
  9. GRB 250925A: MAO/AZT-22 optical observations
  10. Fermi GRB 250929A: Global MASTER-Net observations report
  11. GRB 250929A: Fermi GBM Final Real-time Localization
  12. GRB 250926A: CALET Gamma-Ray Burst Monitor detection
  13. GRB 250925A: Mondy I-band optical observations
  14. GRB 250916A: SVOM/VT optical observation
  15. LIGO/Virgo/KAGRA S250929c: Identification of a GW compact binary merger candidate
  16. LIGO/Virgo/KAGRA S250927ck: Updated Sky localization
  17. Fermi-LAT Gamma-ray Observations of IceCube-250926A
  18. GRB 250926A: triangulation location with Insight-HXMT/HE and Fermi/GBM
  19. GRB 250924A: SVOM/GRM observation
  20. GRB 250925A: Swift-XRT refined Analysis
  21. LIGO/Virgo/KAGRA S250927cy: Identification of a GW compact binary merger candidate
  22. LIGO/Virgo/KAGRA S250927ck: Identification of a GW compact binary merger candidate
  23. IceCube-250926A: Upper limits from a search for additional neutrino events in IceCube
  24. GRB 250926A: Insight-HXMT detection
  25. GRB 250926B: Fermi GBM Final Localization
  26. Fermi trigger No 780609036: Global MASTER-Net observations report
  27. IceCube Alert 250926.52: Global MASTER-Net observations report
  28. GRB 250920C: ULL-ASTRO-MASTER early detection of the optical afterglow with LCO 40-cm telescope at Siding Spring Observatory
  29. GRB 250926A: AstroSat CZTI detection
  30. GRB 250925A: Swift/UVOT Upper Limits
  31. GRB 250925A: Swift-BAT refined analysis
  32. GRB 250925A: Mondy and AbAO optical observations
  33. GRB 250925A: COLIBRÍ photometric redshift
  34. IceCube-250926A - IceCube observation of a high-energy neutrino candidate track-like event
  35. GRB 250925A: SVOM/GWAC-F60A upper limit
  36. GRB 250925A/EP250925a: EP-WXT detection
  37. GRB 250926A: DDOTI Optical Observations and Spatial Coincidence with the Orion Nebula
  38. GRB 250925A : MITSuME Akeno optical upper limits
  39. GRB 250925A: JinShan optical observations
  40. GRB 250925A: 1.5m OSN optical detection and redshift with the 10.4m GTC/OSIRIS+
  41. GRB 250919A / EP250919a: Global MASTER Net before, during and after trigger optical observations
  42. GRB 250925A: COLIBRÍ optical photometry of the afterglow
  43. Fermi GRB 250926A: Global MASTER-Net observations report
  44. GRB 250926A: Fermi GBM Final Real-time Localization
  45. GRB 250925A: Optical Observations via Virtual Telescope Project, Italy
  46. GRB250925A: Liverpool Telescope optical observations
  47. GRB 250925A: NOT optical afterglow candidate
  48. GRB 250925A: Leavitt Observatory optical upper limit
  49. GRB 250925A: Enhanced Swift-XRT position
  50. GRB 250924A: Swift-BAT refined analysis
  51. GRB 250925A: GROWTH-India Telescope Upper Limits
  52. GRB 250925A: Swift detection of a burst
  53. Swift GRB 250925A: Global MASTER-Net observations report
  54. GRB 250922A: SVOM/GRM observation
  55. GRB 250924A: 1.6m Mephisto optical upper limits
  56. GRB 250924A: SAO RAS optical observations
  57. GRB 250924A: NOT optical observations
  58. GRB 250924A: AstroSat CZTI detection
  59. GRB 250914A: AstroSat CZTI detection
  60. GRB 250920B: AstroSat CZTI detection
  61. GRB 250924A: SVOM/VT optical observation
  62. GRB 250924A: Swift/UVOT Detection
  63. GRB 250924A: Swift-XRT refined Analysis
  64. GRB 250924A: Enhanced Swift-XRT position
  65. GRB 250924A: J-band detection with WINTER
  66. GRB 250924A: GROWTH-India Telescope Upper Limits
  67. GRB 250924A: KAIT optical observations
  68. GRB 250924A: Mondy optical observations, afterglow fading
  69. GRB 250924A: Kilonova-Catcher optical afterglow detection
  70. GRB 250920C: Kilonova-Catcher optical afterglow detection
  71. GRB 250922B: SVOM/GRM observation
  72. GRB 250920C: TRT optical observation
  73. GRB 250924B: Fermi GBM Final Localization
  74. GRB 250924A: COLIBRÍ optical observations
  75. Swift GRB 250924A: Global MASTER-Net observations report
  76. GRB 250919A / EP250919a: further LCO optical observation
  77. GRB 250924A: DDOTI Detection of the Optical Counterpart
  78. GRB 250924A: Swift detection of a burst with an optical counterpart
  79. GRB 250920B: AbAO optical upper limits
  80. Konus-Wind detection of GRB 250920C
  81. GRB 250920C: KAIT optical observations
  82. GRB 250920C: VLT redshift confirmation z = 1.399
  83. EP250911a: e-MERLIN radio observations
  84. GRB 250920B: CrAO ZTSH optical observations
  85. GRB 250920C: SALT redshift confirmation
  86. GRB 250920C: COLIBRÍ optical observations
  87. GRB 250922C: AstroSat CZTI detection of a short burst
  88. Fermi GRB 250922B: Global MASTER-Net observations report
  89. GRB 250920B: SAO RAS optical observations
  90. GRB 250920C: NIR observations with WINTER
  91. GRB 250920B: NIR observations with WINTER
  92. Fermi trigger No 780156732: Global MASTER-Net observations report
  93. GRB 250922B: Fermi GBM Final Real-time Localization
  94. GRB 250920C: PRIME near-infrared detection
  95. Konus-Wind detection of GRB 250920B
  96. Konus-Wind detection of GRB 250920A
  97. Konus-Wind detection of GRB 250911A
  98. GRB 250916A: Swift/UVOT Detection
  99. GRB 250920B: Glowbug gamma-ray detection
  100. GRB 250916A: CrAO ZTSh R-band optical observations

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