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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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submitter:"Judith Racusin"

32721 results found.

  1. Konus-Wind detection of GRB 251118C (EP251118a)
  2. EP251118a: FTW optical and NIR observations
  3. GRB 251117A: Insight-HXMT/HE detection
  4. GRB 251119A: SVOM trigger sb25111901 is not a GRB
  5. EP251118a: VLT near-infrared observation
  6. GRB 251116D: SVOM/GRM observation of a long GRB
  7. EP251118a: GOTO optical afterglow detection
  8. EP251118a: NOT spectroscopic redshift of z = 1.216
  9. EP251118a: Global MASTER-Net observations report
  10. EP251118a: preliminary result of EP-FXT follow-up observation
  11. GRB 251118A: Fermi-LAT detection
  12. EP251118a: NOT candidate optical counterpart
  13. GRB 251118A: Swift ToO observations
  14. EP251118a: Einstein Probe detected of a fast X-ray transient
  15. Fermi GRB 251118B: Global MASTER-Net observations report
  16. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
  17. GRB 251117A: FTW Observations of Swift candidate X-ray sources
  18. GRB 251116C: SVOM/ECLAIRs refined analysis
  19. GRB 251116B: SVOM/ECLAIRs refined analysis
  20. GRB 251117A: AstroSat CZTI detection
  21. GRB 251114B: Insight-HXMT/HE detection
  22. GRB 251114B: GECAM-B detection of a short burst
  23. GRB 251117A: Fermi GBM observation
  24. GRB 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
  25. LIGO/Virgo/KAGRA S251117dq: Updated Sky localization
  26. GRB 251116D: Insight-HXMT/HE detection
  27. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  28. GRB 251117A: SVOM/GRM observation of a short burst
  29. GRB 251117A: Tiled Swift observations
  30. GRB 251117A: Fermi-LAT detection
  31. LIGO/Virgo/KAGRA S251117dq: Identification of a GW compact binary merger candidate
  32. GRB 251116C: Swift/BAT arcminute localization of a burst
  33. LIGO/Virgo/KAGRA S251112cm: J-GEM follow-up observations
  34. LIGO/Virgo/KAGRA S251112cm: Classification of reported candidates with SOAR/Goodman
  35. GRB 251116B: SVOM/VT optical upper limit
  36. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  37. LIGO/Virgo/KAGRA S251116en: Updated Sky localization
  38. GRB 251116D: Glowbug gamma-ray detection
  39. EP251023a: Assy AZT-20 optical observations
  40. EP251023a: UAFO and AbAO optical observations
  41. LIGO/Virgo/KAGRA S251112cm: EP-FXT follow-up observations
  42. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  43. GRB 251116C: SVOM/VT optical upper limit
  44. GRB 251025B: further Mondy optical observations
  45. GRB 251111A: Mondy optical upper limit
  46. GRB 251116B: EP-FXT follow-up observation
  47. LIGO/Virgo/KAGRA S251116en: Identification of a GW compact binary merger candidate
  48. LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
  49. GRB 251116B: LCO optical upper limits
  50. GRB 251116C: LCO optical upper limits
  51. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  52. LIGO/Virgo/KAGRA S251112cm: AT2025adht follow-up at Maidanak observatory by GRANDMA
  53. GRB 251115A: Tiled Swift observations
  54. GRB 251115A: Fermi-LAT detection
  55. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  56. Fermi GRB 251115A: Global MASTER-Net observations report
  57. LIGO/Virgo/KAGRA S251112cm: DECam GW-MMADS candidates
  58. LIGO/Virgo/KAGRA S251112cm: Updated Sky localization and false alarm rate estimate
  59. GRB 251113A: Glowbug gamma-ray detection
  60. GRB 251113A: AstroSat CZTI detection
  61. GRB 251112A: Swift-BAT refined analysis
  62. Konus-Wind detection of GRB 251108C
  63. Konus-Wind detection of GRB 251103A
  64. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  65. IPN triangulation of GRB 251108C
  66. Fermi GRB 251114A: Global MASTER-Net observations report
  67. LIGO/Virgo/KAGRA S251112cm: Candidates from the Zwicky Transient Facility
  68. LIGO/Virgo/KAGRA S251112cm: TROVE Vetting of TNS Candidates
  69. LIGO/Virgo/KAGRA S251112cm: FTW observations of galaxies within localization region
  70. Fermi GRB 251113A: Global MASTER-Net observations report
  71. GRB 251111A: SVOM/ECLAIRs refined analysis
  72. GRB 251025B: SVOM/ECLAIRs refined analysis
  73. GRB 251112A: Swift/UVOT Upper Limits
  74. LIGO/Virgo/KAGRA S251112cm: ATLAS pre-detections of AT2025adgp and AT2025adgq
  75. LIGO/Virgo/KAGRA S251112cm: Detection of two young transients by BlackGEM/MeerLICHT: AT2025adgp and AT2025adgq
  76. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  77. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  78. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  79. GRB251111A: 1.3m DFOT optical upper limit
  80. LIGO/Virgo/KAGRA S251112cm: Identification of a GW compact binary merger candidate
  81. GRB 251106B: Glowbug gamma-ray detection of a likely short burst
  82. GRB 251111A: SVOM/VT optical observations with X-band data
  83. GRB 251111A: Swift-XRT observations
  84. GRB 251111A: EP-FXT counterpart detection
  85. GRB 251013C: Chandra X-ray observations and jet break detection
  86. GRB 251111A: SVOM/VT optical observations with VHF data
  87. GRB 251111A: KAIT optical upper limit
  88. GRB 251111A: LCO optical observation
  89. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  90. GRB 251103B: Swift-BAT refined analysis
  91. GRB 251106A: Swift/UVOT Upper Limits
  92. GRB 251105B: Insight-HXMT/HE detection
  93. GRB 251106B: Insight-HXMT detection
  94. LIGO/Virgo/KAGRA S251108fi: DDOTI Optical Candidate
  95. GRB 251105A: AstroSat CZTI detection
  96. LIGO/Virgo/KAGRA S251108fi: One counterpart neutrino candidate from IceCube neutrino searches
  97. LIGO/Virgo/KAGRA S251108fi: Updated Sky localization
  98. LIGO/Virgo/KAGRA S251108dn: Updated Sky localization
  99. LIGO/Virgo/KAGRA S251108fi: Identification of a GW compact binary merger candidate
  100. GRB 251102B: SVOM/GRM observation

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