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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"

32725 results found.

  1. GRB 251118C: Glowbug gamma-ray detection of the fast X-ray transient EP251118A
  2. GRB 251118C: Swift/BAT rates detection of a burst with a possible association with EP 251118A
  3. EP251118A / GRB 251118C : MASTER optical counterpart observations
  4. GRB 251118C: SVOM/GRM observation of a possible gamma-ray counterpart of EP251118a
  5. Konus-Wind detection of GRB 251118C (EP251118a)
  6. EP251118a: FTW optical and NIR observations
  7. GRB 251117A: Insight-HXMT/HE detection
  8. GRB 251119A: SVOM trigger sb25111901 is not a GRB
  9. EP251118a: VLT near-infrared observation
  10. GRB 251116D: SVOM/GRM observation of a long GRB
  11. EP251118a: GOTO optical afterglow detection
  12. EP251118a: NOT spectroscopic redshift of z = 1.216
  13. EP251118a: Global MASTER-Net observations report
  14. EP251118a: preliminary result of EP-FXT follow-up observation
  15. GRB 251118A: Fermi-LAT detection
  16. EP251118a: NOT candidate optical counterpart
  17. GRB 251118A: Swift ToO observations
  18. EP251118a: Einstein Probe detected of a fast X-ray transient
  19. Fermi GRB 251118B: Global MASTER-Net observations report
  20. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
  21. GRB 251117A: FTW Observations of Swift candidate X-ray sources
  22. GRB 251116C: SVOM/ECLAIRs refined analysis
  23. GRB 251116B: SVOM/ECLAIRs refined analysis
  24. GRB 251117A: AstroSat CZTI detection
  25. GRB 251114B: Insight-HXMT/HE detection
  26. GRB 251114B: GECAM-B detection of a short burst
  27. GRB 251117A: Fermi GBM observation
  28. GRB 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
  29. LIGO/Virgo/KAGRA S251117dq: Updated Sky localization
  30. GRB 251116D: Insight-HXMT/HE detection
  31. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  32. GRB 251117A: SVOM/GRM observation of a short burst
  33. GRB 251117A: Tiled Swift observations
  34. GRB 251117A: Fermi-LAT detection
  35. LIGO/Virgo/KAGRA S251117dq: Identification of a GW compact binary merger candidate
  36. GRB 251116C: Swift/BAT arcminute localization of a burst
  37. LIGO/Virgo/KAGRA S251112cm: J-GEM follow-up observations
  38. LIGO/Virgo/KAGRA S251112cm: Classification of reported candidates with SOAR/Goodman
  39. GRB 251116B: SVOM/VT optical upper limit
  40. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  41. LIGO/Virgo/KAGRA S251116en: Updated Sky localization
  42. GRB 251116D: Glowbug gamma-ray detection
  43. EP251023a: Assy AZT-20 optical observations
  44. EP251023a: UAFO and AbAO optical observations
  45. LIGO/Virgo/KAGRA S251112cm: EP-FXT follow-up observations
  46. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  47. GRB 251116C: SVOM/VT optical upper limit
  48. GRB 251025B: further Mondy optical observations
  49. GRB 251111A: Mondy optical upper limit
  50. GRB 251116B: EP-FXT follow-up observation
  51. LIGO/Virgo/KAGRA S251116en: Identification of a GW compact binary merger candidate
  52. LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
  53. GRB 251116B: LCO optical upper limits
  54. GRB 251116C: LCO optical upper limits
  55. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  56. LIGO/Virgo/KAGRA S251112cm: AT2025adht follow-up at Maidanak observatory by GRANDMA
  57. GRB 251115A: Tiled Swift observations
  58. GRB 251115A: Fermi-LAT detection
  59. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  60. Fermi GRB 251115A: Global MASTER-Net observations report
  61. LIGO/Virgo/KAGRA S251112cm: DECam GW-MMADS candidates
  62. LIGO/Virgo/KAGRA S251112cm: Updated Sky localization and false alarm rate estimate
  63. GRB 251113A: Glowbug gamma-ray detection
  64. GRB 251113A: AstroSat CZTI detection
  65. GRB 251112A: Swift-BAT refined analysis
  66. Konus-Wind detection of GRB 251108C
  67. Konus-Wind detection of GRB 251103A
  68. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  69. IPN triangulation of GRB 251108C
  70. Fermi GRB 251114A: Global MASTER-Net observations report
  71. LIGO/Virgo/KAGRA S251112cm: Candidates from the Zwicky Transient Facility
  72. LIGO/Virgo/KAGRA S251112cm: TROVE Vetting of TNS Candidates
  73. LIGO/Virgo/KAGRA S251112cm: FTW observations of galaxies within localization region
  74. Fermi GRB 251113A: Global MASTER-Net observations report
  75. GRB 251111A: SVOM/ECLAIRs refined analysis
  76. GRB 251025B: SVOM/ECLAIRs refined analysis
  77. GRB 251112A: Swift/UVOT Upper Limits
  78. LIGO/Virgo/KAGRA S251112cm: ATLAS pre-detections of AT2025adgp and AT2025adgq
  79. LIGO/Virgo/KAGRA S251112cm: Detection of two young transients by BlackGEM/MeerLICHT: AT2025adgp and AT2025adgq
  80. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  81. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  82. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  83. GRB251111A: 1.3m DFOT optical upper limit
  84. LIGO/Virgo/KAGRA S251112cm: Identification of a GW compact binary merger candidate
  85. GRB 251106B: Glowbug gamma-ray detection of a likely short burst
  86. GRB 251111A: SVOM/VT optical observations with X-band data
  87. GRB 251111A: Swift-XRT observations
  88. GRB 251111A: EP-FXT counterpart detection
  89. GRB 251013C: Chandra X-ray observations and jet break detection
  90. GRB 251111A: SVOM/VT optical observations with VHF data
  91. GRB 251111A: KAIT optical upper limit
  92. GRB 251111A: LCO optical observation
  93. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  94. GRB 251103B: Swift-BAT refined analysis
  95. GRB 251106A: Swift/UVOT Upper Limits
  96. GRB 251105B: Insight-HXMT/HE detection
  97. GRB 251106B: Insight-HXMT detection
  98. LIGO/Virgo/KAGRA S251108fi: DDOTI Optical Candidate
  99. GRB 251105A: AstroSat CZTI detection
  100. LIGO/Virgo/KAGRA S251108fi: One counterpart neutrino candidate from IceCube neutrino searches

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