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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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23687 results found.

  1. LIGO/Virgo/KAGRA S251112cm: Classification of reported candidates with SOAR/Goodman
  2. GRB 251116B: SVOM/VT optical upper limit
  3. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  4. GRB 251116C: Swift-XRT observations
  5. GRB 251116D: Glowbug gamma-ray detection
  6. EP251023a: Assy AZT-20 optical observations
  7. GRB 251116D: AstroSat CZTI detection
  8. GRB 251116C: SVOM/VT optical upper limit
  9. LIGO/Virgo/KAGRA S251116en: Identification of a GW compact binary merger candidate
  10. LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
  11. GRB 251116B: LCO optical upper limits
  12. GRB 251116C: LCO optical upper limits
  13. GRB 251116C: SVOM detection of a burst
  14. GRB 251116B: SVOM detection of a burst
  15. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  16. LIGO/Virgo/KAGRA S251112cm: AT2025adht follow-up at Maidanak observatory by GRANDMA
  17. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 4-Update Localization Volume
  18. GRB 251113A: Glowbug gamma-ray detection
  19. GRB 251113A: AstroSat CZTI detection
  20. GRB 251112A: Swift-BAT refined analysis
  21. Konus-Wind detection of GRB 251108C
  22. Konus-Wind detection of GRB 251103A
  23. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  24. LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
  25. LIGO/Virgo/KAGRA S251112cm: Candidates from the Zwicky Transient Facility
  26. LIGO/Virgo/KAGRA S251112cm: TROVE Vetting of TNS Candidates
  27. GRB 251111A: SVOM/ECLAIRs refined analysis
  28. GRB 251025B: SVOM/ECLAIRs refined analysis
  29. LIGO/Virgo/KAGRA S251112cm: ATLAS pre-detections of AT2025adgp and AT2025adgq
  30. GRB 251108C: AstroSat CZTI detection
  31. GRB 251112B: MAXI/GSC detection
  32. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  33. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  34. GRB 251108B: Glowbug gamma-ray detection
  35. Swift Trigger 1413695: a possible GRB 251112A
  36. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 3-Initial Localization Volume
  37. LIGO/Virgo/KAGRA S251112cm: Identification of a GW compact binary merger candidate
  38. GRB 251106B: Glowbug gamma-ray detection of a likely short burst
  39. GRB 251111A: Swift-XRT observations
  40. GRB 251111A: EP-FXT counterpart detection
  41. GRB 251013C: Chandra X-ray observations and jet break detection
  42. GRB 251111A: KAIT optical upper limit
  43. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  44. GRB 251103B: Swift-BAT refined analysis
  45. GRB 251106A: Swift/UVOT Upper Limits
  46. LIGO/Virgo/KAGRA S251108fi: DDOTI Optical Candidate
  47. GRB 251105A: AstroSat CZTI detection
  48. LIGO/Virgo/KAGRA S251108fi: One counterpart neutrino candidate from IceCube neutrino searches
  49. LIGO/Virgo/KAGRA S251108fi: Identification of a GW compact binary merger candidate
  50. GRB 251102B: SVOM/GRM observation
  51. LIGO/Virgo/KAGRA S251108dn: Identification of a GW compact binary merger candidate
  52. The EP-WXT trigger 01709248051 is likely a flaring star
  53. IPN triangulation of GRB 251105B (possible sGRB with EE)
  54. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) fading of the optical counterpart
  55. GRB 251106A: Kilonova-Catcher optical upper limit
  56. Fermi GBM Sub-Threshold Detection of GRB 251106A
  57. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) detection of a likely optical counterpart
  58. GRB 251106A: SVOM detection of a burst
  59. GRB 251103B: AstroSat CZTI detection
  60. GRB 251025C: TERI Gamma-ray detection
  61. GRB 251016B: TERI Gamma-ray detection
  62. GRB 251016A: TERI Gamma-ray detection of a short burst
  63. GRB 250920C: TERI Gamma-ray detection
  64. EP251102a: Xinglong 2.16-m clear-band observations of the optical counterpart
  65. GRB 251104A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  66. GRB 251105B: AstroSat CZTI detection of a short burst with extended emission
  67. GRB 251023A: SVOM/ECLAIRs detection of a burst through targeted search
  68. LIGO/Virgo/KAGRA S251105aj: Identification of a GW compact binary merger candidate
  69. GRB 251103B: Fermi GBM observation
  70. GRB 251104A: SVOM detection of a burst
  71. GRB 251103A: Xinglong 2.16m optical detection
  72. GRB 251103A: KAIT optical observations
  73. GRB 251013C: 7DT detection and Medium-band SED of Afterglow
  74. GRB 251103B: MITSuME Akeno optical upper limits
  75. LIGO/Virgo/KAGRA S251103f: Identification of a GW compact binary merger candidate
  76. EP251102a: NIR observations with WINTER
  77. GRB 251103A: J-band detection with WINTER
  78. GRB 251103A: Kilonova-Catcher optical afterglow detection
  79. GRB 251103B: Swift detection of a burst
  80. GRB 251103A: Fermi GBM Observation
  81. GRB 251103A: Swift-XRT afterglow detection
  82. GRB 251103A: SVOM/COLIBRÍ (FM-GFT) optical observations
  83. GRB 251103A: LCO optical observation
  84. EP251102.890: COLIBRÍ optical counterpart candidate
  85. GRB 251103A: GOTO optical afterglow detection
  86. GRB 251102A: AstroSat CZTI detection
  87. GRB 251026A: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical counterpart
  88. GRB 251103A: BOOTES-2/TELMA optical afterglow
  89. LIGO/Virgo/KAGRA S251031cq: Identification of a GW compact binary merger candidate
  90. Konus-Wind detection of GRB 251028A
  91. IceCube-251025A: Two Transient Candidates from the Zwicky Transient Facility
  92. GRB 251022A: Swift-XRT confirmation of fading
  93. GRB 250926B: VZLUSAT-2 detection
  94. GRB 250926A: VZLUSAT-2 detection
  95. GRB 250925A: VZLUSAT-2 detection
  96. GRB 251026B: Fermi GBM Observation
  97. GRB 251028B: Glowbug gamma-ray detection
  98. GRB 251028A: Glowbug gamma-ray detection
  99. GRB 251028B: CALET Gamma-Ray Burst Monitor detection
  100. Fermi GRB 251028B: Global MASTER-Net observations report

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