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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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To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
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submitter:"Judith Racusin"

28245 results found.

  1. EP250508a: KAIT optical upper limit
  2. GRB 250507A: KAIT optical upper limit
  3. EP250508a: refined analysis of the EP-WXT and EP-FXT observations
  4. GRB 250505B: SVOM/GRM observation of a short burst
  5. GRB 250502A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  6. EP250508a: REM optical/NIR observations
  7. GRB 250506A: Swift-XRT afterglow detection
  8. EP250508a: COLIBRÍ Optical Limit
  9. EP250508a: Einstein Probe detection of an X-ray transient
  10. GRB 250507A: Swift-XRT refined Analysis
  11. IceCube-250506A: Upper limits from a search for additional neutrino events in IceCube
  12. GRB 250506A: Swift/UVOT Upper Limits
  13. GRB 250507A: follow-up observation with EP-FXT
  14. GRB 250506A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  15. GRB 250507A: REM optical/NIR observations
  16. GRB 250507A: SVOM/VT optical upper limit
  17. GRB 250506A: Swift-XRT observations
  18. Fermi-LAT Gamma-ray Observations of IceCube-250506A
  19. GRB 250507A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  20. EP-WXT trigger 01709175213: a new X-ray outburst of LMXB MAXI J1957+032
  21. GRB 250507A: SVOM detection of a long burst
  22. GRB 250506A: Mephisto optical upper limits
  23. GRB 250504A: EIRSAT-1 GMOD Detection
  24. GRB 250502A: Bassano Bresciano Observatory upper limit
  25. GRB 250506A: Xinglong 2.16m optical upper limit
  26. SVOM/sb25050601: EP-FXT observations
  27. GRB 250506A: SVOM improved position and MXT detection of a fading X-ray afterglow
  28. GRB 250506A: REM optical/NIR upper limits
  29. GRB 250506A: Fermi GBM Observation
  30. GRB 250506A: Swift XRT observations and possible counterpart detection
  31. GRB 250506A: TRT optical observations
  32. GRB 250506A: SVOM/COLIBRÍ (FM-GFT) Upper Limits on the Optical Counterpart
  33. GRB 250506A: SVOM detection of a burst
  34. GRB 250504A: Swift-BAT refined analysis
  35. GRB 250430A: Swift-BAT refined analysis
  36. GRB 250504A: Swift-XRT refined Analysis
  37. GRB 250504A: VLT/X-shooter upper limits
  38. GRB 250504A: REM optical/NIR observations
  39. GRB 250502A: REM optical/NIR observations
  40. GRB 250504A: MeerLICHT optical afterglow detection
  41. GRB 250504A: Fermi GBM Observation
  42. GRB 250504A: Enhanced Swift-XRT position
  43. Fermi GRB 250504A: Global MASTER-Net observations report
  44. GRB 250504A: Swift detection of a burst
  45. GRB 250502A: Swift/UVOT Follow up
  46. GRB 250502A: Mondy and Tien-Shan Optical Observations
  47. GRB 250502A: KAIT optical observations
  48. GRB 250502A: Montarrenti Observatory optical detection
  49. GRB 250502A: Swift-XRT afterglow detection
  50. GRB 250502A: NOT optical observations
  51. GRB 250502B: AstroSat CZTI detection
  52. GRB 250502A: AKO Optical Afterglow Detection
  53. GRB 250502A: LCO optical counterpart detection
  54. GRB 250502A: Redshift from OSIRIS+/GTC z = 2.163
  55. GRB 250407A: VZLUSAT-2 detection
  56. Fermi-LAT Gamma-ray Observations of IceCube-250429A
  57. GRB 250502B: DDOTI Optical Observations
  58. GRB 250430A: Swift-XRT refined Analysis
  59. GRB 250502A: Early optical counterpart detection by LCO.
  60. GRB 250430A: Swift/UVOT Detection
  61. GRB 250502A: TRT optical afterglow confirmation
  62. GRB 250430A: Enhanced Swift-XRT position
  63. GRB 250502A: SVOM/COLIBRÍ (FM-GFT) Detection of a Bright Optical Counterpart Candidate
  64. GRB 250502A: SVOM detection of a burst
  65. GRB 250430A: Calapai Observatory, Massa S. Giorgio (Messina), upper limit
  66. GRB 250430A: KAIT optical observations
  67. GRB 250430A / EP250430a: J-band upper limits with WINTER
  68. GRB 250430A: NUTTelA-TAO Early Measurements
  69. GRB 250430A: DDOTI Optical Observations
  70. GRB 250430A: Leavitt Observatory optical upper limit
  71. GRB 250430A: Bassano Bresciano Observatory upper limit
  72. GRB 250430A : MITSuME Akeno optical upper limits
  73. SVOM/sb25043004: EP-FXT observations
  74. EP250430a/GRB 250430A: Einstein Probe WXT detection of the X-ray prompt emission
  75. GRB 250424A: CALET Gamma-Ray Burst Monitor detection
  76. IceCube-250429A: Upper limits from a search for additional neutrino events in IceCube
  77. IceCube-250426A: Upper limits from a search for additional neutrino events in IceCube
  78. GRB 250430A: AKO Optical Afterglow Detection
  79. GRB 250430A: Kanata optical upper limit
  80. EP 250427A: Optical counterpart detection by LCO.
  81. GRB 250430A: Swift detection of a burst with optical counterpart
  82. EP250427a/GRB250427A: HCT optical follow-up
  83. SVOM/sb25043004: SVOM detection of a X-ray transient
  84. EP250428b: GROWTH-India telescope optical upper limit
  85. EP250428b: SAO RAS optical upper limit
  86. EP250428b: LAST optical upper limit
  87. GRB 250427A: Swift/UVOT Detection
  88. EP250428b: Global MASTER-Net observations report
  89. EP250428b: Einstein Probe detection of a fast X-ray transient
  90. Fermi-LAT Gamma-ray Observations of IceCube-250426A
  91. EP250427a: Lesedi optical counterpart detection
  92. EP250427A: COLIBRÍ Continuing Optical Observations
  93. GRB250427A/EP250427a GIT optical afterglow detection:
  94. EP250427a: LT optical counterpart detection
  95. GRB 250427A: Swift-XRT refined Analysis
  96. EP250427a / GRB 250427A: LCO optical counterpart detection
  97. EP250427a: REM optical/NIR afterglow detection
  98. GRB 250424A: LCO optical observation
  99. GRB 250427A/ EP250427a: Fermi-GBM Sub-Threshold Detection
  100. EP250427A: COLIBRÍ Optical Detection

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