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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').
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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

18515 results found.

  1. GRB 250129A: COLIBRÍ Optical Observations
  2. GRB 250129A: iTelescope optical observation
  3. GRB 250129a: Liverpool Telescope optical follow-up
  4. GRB 250129A: TNG NIR afterglow detection
  5. GRB 250129A: AKO Optical Afterglow Detection
  6. GRB 250129A: GRANDMA/TAROT optical afterglow detection
  7. GRB 250127A: EP-FXT second observation epoch and confirmation of the x-ray afterglow fading
  8. GRB 250128B: SAO RAS Zeiss-1000 and CrAO ZTSh optical upper limits
  9. GRB 250128B: VLA radio upper limit
  10. Ep250125A: 1.3m DFOT optical upper limit
  11. GRB 250129A: Skynet optical observations
  12. GRB 250128B: TNG optical upper limit
  13. GRB 250129A: Swift/UVOT Detection
  14. GRB 250128B: VLT/HAWKI near-infrared observations
  15. GRB 250127A: CrAO and Terskol optical upper limits
  16. GRB 250129A: Enhanced Swift-XRT position
  17. GRB 250128B: NOT optical upper limit
  18. GRB 250128B: VLT/FORS2 optical observations
  19. GRB 250129A: REM optical/NIR afterglow detection
  20. GRB 250129A: OHP/T193 optical and spectroscopy observations
  21. GRB 250129A: Early afterglow detection by LCO.
  22. GRB 250128B: OHP/T193 optical upper limit
  23. GRB 250129A: LCO optical observations
  24. GRB 250128B: Enhanced Swift-XRT position
  25. The EP-WXT trigger 01709131085 is likely a flaring star
  26. Fermi GRB 250128B: Global MASTER-Net observations report
  27. GRB 250129A: Swift detection of a burst with an optical counterpart
  28. GRB 250128B: Swift-XRT refined Analysis
  29. GRB 250128B: Fermi GBM Observation
  30. GRB 250128B: GOTO optical upper limit
  31. GRB 250128B: LCO optical observations
  32. GRB 250128B: Swift detection of a short burst
  33. GRB 250127A: Swift-XRT observations
  34. GRB 250127B: DDOTI Upper Limit on the Afterglow
  35. GRB 250127A: EP-FXT afterglow detection
  36. IPN triangulation of GRB 250119C
  37. GRB 250127A: LCO optical upper limit
  38. EP250125a: Optical upper limit with Kinder observations
  39. EP250125a: REM optical counterpart detection
  40. EP250125a: a new X-ray transient detected by Einstein Probe
  41. EP250125a: Gemini-South optical afterglow discovery and redshift z = 2.89
  42. The EP-WXT trigger 01709130758 is a false trigger
  43. The EP-WXT trigger 01709130758 is a false trigger
  44. GRB 250121A: Swift/BAT-GUANO localization skymap of a burst
  45. EP250108a: AbAO, CMO and Terskol optical upper limits
  46. IPN triangulation of GRB 250118B
  47. IPN triangulation of GRB 250119B
  48. LIGO/Virgo S250119cv: Swift XRT observations, 5 X-ray sources
  49. GRB 250119C: Swift/BAT-GUANO localization skymap of a short burst
  50. GRB 250119B: Swift/BAT-GUANO localization skymap of a long burst
  51. Fermi-LAT Gamma-ray Observations of IceCube-241224A
  52. GRB 250118A: Swift/BAT-GUANO localization skymap of a short burst
  53. EP250108a/AT2025kg: 1.3m DFOT Optical observations
  54. IPN triangulation of GRB 250117A (short)
  55. EP250108a / SN2025kg: Non-detection from ATCA radio follow-up observations
  56. EP 250108A: Late-time optical observation by LCO
  57. LIGO/Virgo/KAGRA S250119cv: Updated Sky localization and EM Bright Classification
  58. GRB 250117A: Swift/BAT-GUANO localization skymap of a short burst
  59. EP250108a / AT2025kg: GMG Optical Observations
  60. GRB 241217A / EP241217B: radio detection with the VLA
  61. GRB 250114B: Swift-XRT afterglow detection
  62. EP250108a: MeerKAT radio upper limit
  63. GRB 250101A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations and rebrightening.
  64. IPN triangulation of GRB 250113A
  65. GRB 250114B: Liverpool Telescope optical upper limit
  66. GRB 250114B : MITSuME Akeno optical afterglow candidate detection
  67. GRB 250114A: LCO optical counterpart detection.
  68. GRB 250114B: OHP/T193 optical upper limit
  69. GRB 250114A: GRANDMA/TAROT optical afterglow detection
  70. GRB 250114A: Swift-XRT refined Analysis
  71. GRB 250114A: LCOGT optical afterglow i-band detection
  72. GRB 250114B : GIT optical upper limit
  73. EP250111a: SAO RAS optical upper limit
  74. GRB 250114A: Enhanced Swift-XRT position
  75. GRB 250114A: REM detection of the optical and NIR counterpart
  76. LIGO/Virgo/KAGRA S250114ax: Identification of a GW compact binary merger candidate
  77. GRB 250114A: LCO optical observations
  78. GRB 250114A: TRT optical observations
  79. GRB 250114A: Swift detection of a burst with an optical counterpart
  80. GRB 250101A: Terskol Zeiss-2000 optical observations
  81. EP250108a / AT 2025kg: SAO RAS optical observations
  82. EP241021a: SMA radio observation
  83. GRB 250113A: SVOM/GRM observation of a long burst
  84. GRB 250107A: VZLUSAT-2 detection
  85. EP250109b: optical upper limits with the Liverpool Telescope
  86. GRB 250106A: Swift-XRT afterglow detection
  87. Fermi trigger No 758442826: Global MASTER-Net observations report
  88. EP250111a: KAIT optical observations
  89. GRB 250109A / EP250109a: Mephisto optical upper limits
  90. EP250108a: Mephisto detection
  91. EP250111a: Mondy optical observation
  92. EP250108a / AT 2025kg: LCO optical observations
  93. EP250111a: NOT likely optical counterpart
  94. EP250111a: a new X-ray transient detected by Einstein Probe
  95. EP250108a: further NOT optical observations
  96. GRB 250109A / EP250109a: Terskol (INASAN) and SAO RAS observations
  97. GRB 250109A / EP250109A: Swift/BAT-GUANO localization skymap of a burst
  98. GRB 250109A / EP250109a: Swift detection of the X-ray afterglow
  99. EP-WXT trigger EP250108a：Xinglong optical follow-up observations
  100. GRB 250101A: CMO RC-500 optical observations

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