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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"

29107 results found.

  1. Fermi GRB 251125B: Global MASTER-Net observations report
  2. GRB 251125B: Fermi GBM Final Real-time Localization
  3. EP251124b: Global MASTER-Net observations report
  4. EP251124a: Xinglong GWAC-F60A optical observation
  5. EP251124a (EP-WXT trigger 01709248862) is triggered by the known source AWM 7
  6. Fermi GRB 251125A: Global MASTER-Net observations report
  7. GRB 251125A: Fermi GBM Final Real-time Localization
  8. EP251124a: NOT r- and z-band optical upper limits
  9. EP251124a: Global MASTER-Net observations report
  10. EP251124a: Swift-XRT observations
  11. GRB 251124A: Fermi GBM Localization by automated pipeline
  12. LIGO/Virgo/KAGRA S251112cm: AT 2025adht Kinder follow-up observations
  13. EP251124a: Optical upper limit with Kinder observations
  14. GRB 251122B: Fermi GBM Final Localization
  15. EP251118A: 6 GHz VLA Detection
  16. Fermi GRB 251124a: Global MASTER-Net observations report
  17. GRB 251124a: Fermi GBM Final Localization
  18. LIGO/Virgo/KAGRA S251105aj: EP-FXT follow-up observations and preliminary results on SVOM J2320.0-2901
  19. EP251124a: GROWTH-India Telescope optical upper limits
  20. GRB 251122A/EP251122a: FTW optical and NIR observations
  21. GRB 251122A/EP251122A: 1.3m DFOT optical detection
  22. The EP-WXT trigger 01709248783 is likely a flaring star
  23. GRB 251122A / EP251122a: Xinglong 2.16m optical observation
  24. EP251118A: 3.6m DOT optical afterglow detection
  25. GRB 251122A / EP251122a: EP-FXT counterpart detection
  26. GRB 251122A / EP251122a: WFST optical observations
  27. GRB 251122A/EP251122a: SVOM/VT optical observations with VHF data
  28. GRB 251122A / EP251122a: LCO optical upper limits
  29. EP251122a / GRB 251122A: optical counterpart candidate with Kinder observations
  30. EP251122a: Global MASTER-Net observations report
  31. GRB 251122A/EP251122a: SVOM/C-GFT upper limit
  32. GRB 251122A / EP251122a: SVOM detection of a long burst
  33. EP251118a: Continued Optical Detection with Kinder observations
  34. LIGO/Virgo/KAGRA S251105aj: SVOM/ECLAIRs detection of a high-energy transient SVOM J2320.0-2901 through targeted search
  35. GRB 251121A: Swift/BAT-GUANO localization skymap of a short burst
  36. GRB 251121A: Glowbug gamma-ray detection of a likely short burst
  37. EP251118a: Xinglong-2.16m optical observation
  38. GRB 251115A: Fermi GBM Observation
  39. The EP-WXT trigger 01709248635 is likely a flaring star
  40. GRB 251121A: Fermi GBM Final Real-time Localization
  41. Fermi Gamma-ray Burst Monitor trigger 785388351 / 251121143 is not a GRB
  42. Fermi trigger No 785388351: Global MASTER-Net observations report
  43. EP251118A: 1.3m DFOT optical afterglow detection
  44. GRB 251118A: Swift/UVOT Detection
  45. GRB 251118A: Glowbug gamma-ray detection
  46. GRB 251118A: Fermi GBM Observation
  47. GRB 251118A: Swift-XRT afterglow detection
  48. GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
  49. EP251118a: Optical detection with Kinder observations
  50. GRB 251118A: GECAM-B detection
  51. EP-WXT trigger 01709248403: confirmation of a stellar flare by SVOM/VT
  52. The EP-WXT trigger 01709248403 is likely a flaring star
  53. GRB 251118A: NuSTAR detection of bright prompt emission
  54. EP251118a / GRB 251118C: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at CTIO
  55. GRB 251116C: NOT optical observations
  56. GRB 251118C: Swift/BAT rates detection of a burst with a possible association with EP 251118A
  57. GRB 251018A: FRAM-Auger optical detection
  58. GRB 251117A: Swift-XRT observations
  59. The EP-WXT trigger 01709248388 is likely a flaring star
  60. EP251118a: FTW optical and NIR observations
  61. GRB 251117A: Insight-HXMT/HE detection
  62. GRB 251119A: SVOM trigger sb25111901 is not a GRB
  63. EP251118a: VLT near-infrared observation
  64. GRB 251116D: SVOM/GRM observation of a long GRB
  65. EP251118a: GOTO optical afterglow detection
  66. GRB 251119A: SVOM detection of a possible burst
  67. EP251118a: Global MASTER-Net observations report
  68. LAT GRB251118.86: Global MASTER-Net observations report
  69. GRB 251118A: Fermi-LAT detection
  70. EP251118a: NOT candidate optical counterpart
  71. GRB 251118A: Swift ToO observations
  72. EP251118a: Einstein Probe detected of a fast X-ray transient
  73. Fermi GRB 251118B: Global MASTER-Net observations report
  74. GRB 251118B: Fermi GBM Final Real-time Localization
  75. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
  76. GRB 251118A: BALROG localization (Fermi Trigger 785190695 / GRB 251118855)
  77. GRB 251117A: FTW Observations of Swift candidate X-ray sources
  78. GRB 251118A: Fermi GBM Final Real-time Localization
  79. GRB 251116C: SVOM/ECLAIRs refined analysis
  80. GRB 251117A: AstroSat CZTI detection
  81. GRB 251114B: Insight-HXMT/HE detection
  82. GRB 251114B: GECAM-B detection of a short burst
  83. GRB 251117A: Fermi GBM observation
  84. GRB 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
  85. GRB 251115A: Swift-XRT observations
  86. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  87. GRB 251117A: SVOM/GRM observation of a short burst
  88. GRB 251117A: Tiled Swift observations
  89. GRB 251117A: Fermi-LAT detection
  90. LAT GRB251117.51: Global MASTER-Net observations report
  91. GRB 251116B: SVOM/VT optical upper limit
  92. GRB 251116C: Swift-XRT observations
  93. GRB 251117A: Fermi GBM Final Localization Correction
  94. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  95. GRB 251116C: SVOM/VT optical upper limit
  96. GRB 251116B: EP-FXT follow-up observation
  97. GRB 251116B: LCO optical upper limits
  98. GRB 251116C: LCO optical upper limits
  99. SVOM GRB251116C: Global MASTER-Net observations report
  100. GRB 251116C: SVOM detection of a burst

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