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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"

45772 results found.

  1. EP251130a: KAIT optical observations
  2. EP251130A: Optical observation from 1.3m DFOT
  3. EP251130a: refined analysis of the EP-WXT and EP-FXT observations
  4. EP251130a: JinShan optical observations
  5. GRB 251201A: MAXI/GSC detection
  6. Fermi GRB 251130B: Global MASTER-Net observations report
  7. GRB 251127A: SVOM/GRM observation
  8. IceCube Alert 251130.75: Global MASTER-Net observations report
  9. IceCube-251130A - IceCube observation of a high-energy neutrino candidate track-like event
  10. EP251130a: Swift-XRT counterpart detection
  11. GRB 251130B: Fermi GBM Final Localization Correction
  12. EP251130a: Global MASTER-Net observations report
  13. GRB 251130B: Fermi GBM Final Real-time Localization
  14. EP251130a: COLIBRÍ optical counterpart candidate
  15. EP251130a: Einstein Probe detection of an X-ray transient
  16. EP251129a/GRB 251129A: EP-FXT follow-up observations
  17. GRB 251130A: Fermi GBM Final Real-time Localization
  18. GRB 251129A / EP251129a: GTC/OSIRIS+ spectroscopic redshift z = 1.460
  19. GRB 251129A / EP251129a: OSN and CAHA optical follow-up
  20. GRB 251128A: AstroSat CZTI detection
  21. GRB 251129A / EP251129a: SAO RAS optical observations
  22. GRB 251126A: SAO RAS optical observations
  23. GRB 251128A: GECAM-B detection
  24. GRB 251128A: SVOM/GRM observation of a long burst
  25. GRB 251128A: Insight-HXMT/HE detection
  26. SVOM GRB 251129A : MASTER optical counterpart detection
  27. GRB 251129A: Swift-XRT afterglow detection
  28. The EP-WXT trigger 01709248941 is triggered by the known source Perseus Cluster
  29. Swift trigger 1418333 is not an astrophysical source
  30. GRB 251129A: Swift ToO observations
  31. GRB 251129A / EP251129a: SVOM/VT optical fading
  32. EP251129a: Global MASTER-Net observations report
  33. GRB 251129A: Optical Observations via Virtual Telescope Project, Italy
  34. EP251129a/GRB 251129A : Einstein Probe detection of an X-ray transient
  35. GRB 251129A: Correction to the position of the optical counterpar
  36. GRB 251129A: SVOM/VT optical counterpart confirmation with VHF data
  37. GRB 251128A: Fermi GBM Observation
  38. GRB 251129A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  39. GRB 251129A: SVOM detection of a burst
  40. SVOM GRB251129A: Global MASTER-Net observations report
  41. GRB 251129A: SVOM detection of a burst
  42. GRB 251126A: Swift-BAT refined analysis
  43. GRB 251126A: TShAO, Mondy, and AbAO optical observations
  44. GRB 251128A: Swift/BAT-GUANO localization skymap of a burst
  45. Fermi GRB 251128A: Global MASTER-Net observations report
  46. GRB 251127A: Glowbug gamma-ray detection
  47. GRB 251126A: OHP/T193 optical observations and tentative spectroscopic redshift
  48. GRB 251126A: further SAO RAS optical observations
  49. GRB 250702B: detection of the compact radio counterpart 139 days after the burst
  50. GRB 251126A NUTTelA-TAO Early Measurements
  51. LIGO/Virgo/KAGRA S251112cm: GECKO/KMTNet tiling observations and transient candidates
  52. GRB251126A: MAO/AZT-22 optical observations
  53. GRB 251128A: Fermi GBM Final Real-time Localization
  54. GRB251126A: Continued optical observation from 1.3m DFOT
  55. GRB 251126A: Swift/UVOT Detection
  56. EP251124a: Pan-STARRS ri-band imaging and photometry
  57. GRB 251126A: Mondy and SAO RAS optical observations
  58. GRB 251126A: Swift-XRT refined Analysis
  59. GRB 251126A : MITSuME Akeno optical afterglow candidate detection
  60. GRB 251126A: NOT optical observations
  61. GRB 251126A: 1.3m DFOT optical afterglow detection
  62. GRB 251126A: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at McDonald Observatory
  63. GRB 251126A: COLIBRÍ photometric redshift z = 3.5
  64. GRB 251125B: GECAM-B detection
  65. Fermi GRB 251127A: Global MASTER-Net observations report
  66. GRB 251127A: Fermi GBM Final Real-time Localization
  67. GRB 251126A: Enhanced Swift-XRT position
  68. GRB 251126A: Kilonova-Catcher optical afterglow detection
  69. GRB 251126A: Asiago i-band detection
  70. GRB 251126A: Nanshan/HMT optical afterglow detection
  71. Swift GRB 251126A: Global MASTER-Net observations report
  72. GRB 251121A: Fermi GBM Observation
  73. GRB 251126A: Prompt enhanced Swift-XRT position
  74. GRB 251126A: GIT discovery of the likely optical afterglow
  75. GRB 251126A: Swift detection of a burst
  76. GRB 251125B: COLIBRÍ further observations and photometric redshift upper limit of z < 3
  77. EP251124b follow-up observation by EP-FXT
  78. GRB 251125B: COLIBRÍ observations of fading of the MASTER OT candidate
  79. EP251124b: NOT r- and z-band optical upper limits
  80. Fermi GRB 251125B : MASTER OT J155558.56+581224.1 optical counterpart discovery
  81. Fermi GRB 251125B: Global MASTER-Net observations report
  82. GRB 251125B: Fermi GBM Final Real-time Localization
  83. EP251124b: Global MASTER-Net observations report
  84. EP251124b: EP-WXT detection of a fast X-ray transient
  85. EP251124a: Xinglong GWAC-F60A optical observation
  86. EP251124a (EP-WXT trigger 01709248862) is triggered by the known source AWM 7
  87. Fermi GRB 251125A: Global MASTER-Net observations report
  88. GRB 251125A: Fermi GBM Final Real-time Localization
  89. EP251124a: NOT r- and z-band optical upper limits
  90. EP251124a: Global MASTER-Net observations report
  91. EP251124a: Swift-XRT observations
  92. GRB 251124A: Fermi GBM Localization by automated pipeline
  93. LIGO/Virgo/KAGRA S251112cm: AT 2025adht Kinder follow-up observations
  94. EP251124a: Optical upper limit with Kinder observations
  95. GRB 251122B: Fermi GBM Final Localization
  96. EP251118A: 6 GHz VLA Detection
  97. Fermi GRB 251124a: Global MASTER-Net observations report
  98. GRB 251124a: Fermi GBM Final Localization
  99. LIGO/Virgo/KAGRA S251105aj: SVOM/VT optical observations and preliminary results on SVOM J2320.0-2901
  100. LIGO/Virgo/KAGRA S251105aj: EP-FXT follow-up observations and preliminary results on SVOM J2320.0-2901

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