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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"
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32735 results found.

  1. EP251118a / GRB 251118C: SAO RAS optical observations
  2. GRB 251118A: Glowbug gamma-ray detection
  3. GRB 251118A: Fermi GBM Observation
  4. GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
  5. EP251118a: Optical detection with Kinder observations
  6. GRB 251118A: GECAM-B detection
  7. LIGO/Virgo/KAGRA S251112cm: SVOM/VT optical observations and preliminary results
  8. EP251118a / GRB 251118C: SVOM/VT optical observation
  9. GRB 251118A: NuSTAR detection of bright prompt emission
  10. EP251118a / GRB 251118C: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at CTIO
  11. GRB 251116C: NOT optical observations
  12. GRB 251118C: Glowbug gamma-ray detection of the fast X-ray transient EP251118A
  13. GRB 251118C: Swift/BAT rates detection of a burst with a possible association with EP 251118A
  14. EP251118A / GRB 251118C : MASTER optical counterpart observations
  15. GRB 251118C: SVOM/GRM observation of a possible gamma-ray counterpart of EP251118a
  16. Konus-Wind detection of GRB 251118C (EP251118a)
  17. EP251118a: FTW optical and NIR observations
  18. GRB 251117A: Insight-HXMT/HE detection
  19. GRB 251119A: SVOM trigger sb25111901 is not a GRB
  20. EP251118a: VLT near-infrared observation
  21. GRB 251116D: SVOM/GRM observation of a long GRB
  22. EP251118a: GOTO optical afterglow detection
  23. EP251118a: NOT spectroscopic redshift of z = 1.216
  24. EP251118a: Global MASTER-Net observations report
  25. EP251118a: preliminary result of EP-FXT follow-up observation
  26. GRB 251118A: Fermi-LAT detection
  27. EP251118a: NOT candidate optical counterpart
  28. GRB 251118A: Swift ToO observations
  29. EP251118a: Einstein Probe detected of a fast X-ray transient
  30. Fermi GRB 251118B: Global MASTER-Net observations report
  31. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
  32. GRB 251117A: FTW Observations of Swift candidate X-ray sources
  33. GRB 251116C: SVOM/ECLAIRs refined analysis
  34. GRB 251116B: SVOM/ECLAIRs refined analysis
  35. GRB 251117A: AstroSat CZTI detection
  36. GRB 251114B: Insight-HXMT/HE detection
  37. GRB 251114B: GECAM-B detection of a short burst
  38. GRB 251117A: Fermi GBM observation
  39. GRB 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
  40. LIGO/Virgo/KAGRA S251117dq: Updated Sky localization
  41. GRB 251116D: Insight-HXMT/HE detection
  42. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  43. GRB 251117A: SVOM/GRM observation of a short burst
  44. GRB 251117A: Tiled Swift observations
  45. GRB 251117A: Fermi-LAT detection
  46. LIGO/Virgo/KAGRA S251117dq: Identification of a GW compact binary merger candidate
  47. GRB 251116C: Swift/BAT arcminute localization of a burst
  48. LIGO/Virgo/KAGRA S251112cm: J-GEM follow-up observations
  49. LIGO/Virgo/KAGRA S251112cm: Classification of reported candidates with SOAR/Goodman
  50. GRB 251116B: SVOM/VT optical upper limit
  51. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  52. LIGO/Virgo/KAGRA S251116en: Updated Sky localization
  53. GRB 251116D: Glowbug gamma-ray detection
  54. EP251023a: Assy AZT-20 optical observations
  55. EP251023a: UAFO and AbAO optical observations
  56. LIGO/Virgo/KAGRA S251112cm: EP-FXT follow-up observations
  57. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  58. GRB 251116C: SVOM/VT optical upper limit
  59. GRB 251025B: further Mondy optical observations
  60. GRB 251111A: Mondy optical upper limit
  61. GRB 251116B: EP-FXT follow-up observation
  62. LIGO/Virgo/KAGRA S251116en: Identification of a GW compact binary merger candidate
  63. LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
  64. GRB 251116B: LCO optical upper limits
  65. GRB 251116C: LCO optical upper limits
  66. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  67. LIGO/Virgo/KAGRA S251112cm: AT2025adht follow-up at Maidanak observatory by GRANDMA
  68. GRB 251115A: Tiled Swift observations
  69. GRB 251115A: Fermi-LAT detection
  70. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  71. Fermi GRB 251115A: Global MASTER-Net observations report
  72. LIGO/Virgo/KAGRA S251112cm: DECam GW-MMADS candidates
  73. LIGO/Virgo/KAGRA S251112cm: Updated Sky localization and false alarm rate estimate
  74. GRB 251113A: Glowbug gamma-ray detection
  75. GRB 251113A: AstroSat CZTI detection
  76. GRB 251112A: Swift-BAT refined analysis
  77. Konus-Wind detection of GRB 251108C
  78. Konus-Wind detection of GRB 251103A
  79. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  80. IPN triangulation of GRB 251108C
  81. Fermi GRB 251114A: Global MASTER-Net observations report
  82. LIGO/Virgo/KAGRA S251112cm: Candidates from the Zwicky Transient Facility
  83. LIGO/Virgo/KAGRA S251112cm: TROVE Vetting of TNS Candidates
  84. LIGO/Virgo/KAGRA S251112cm: FTW observations of galaxies within localization region
  85. Fermi GRB 251113A: Global MASTER-Net observations report
  86. GRB 251111A: SVOM/ECLAIRs refined analysis
  87. GRB 251025B: SVOM/ECLAIRs refined analysis
  88. GRB 251112A: Swift/UVOT Upper Limits
  89. LIGO/Virgo/KAGRA S251112cm: ATLAS pre-detections of AT2025adgp and AT2025adgq
  90. LIGO/Virgo/KAGRA S251112cm: Detection of two young transients by BlackGEM/MeerLICHT: AT2025adgp and AT2025adgq
  91. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  92. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  93. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  94. GRB251111A: 1.3m DFOT optical upper limit
  95. LIGO/Virgo/KAGRA S251112cm: Identification of a GW compact binary merger candidate
  96. GRB 251106B: Glowbug gamma-ray detection of a likely short burst
  97. GRB 251111A: SVOM/VT optical observations with X-band data
  98. GRB 251111A: Swift-XRT observations
  99. GRB 251111A: EP-FXT counterpart detection
  100. GRB 251013C: Chandra X-ray observations and jet break detection

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