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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').
Advanced Search

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"
body:"GRB"
submitter:"Judith Racusin"

45796 results found.

  1. GRB 250307A: Fermi GBM Final Real-time Localization
  2. GRB 250306A: Swift-BAT refined analysis
  3. GRB 250306A: NuSTAR detection of the prompt emission
  4. EP250304a: MeerKAT detection of a possible radio counterpart
  5. IceCube-241016A: MASTER flaring blazar 5BZU J073038.29-320820.2 with Zhirkov effect
  6. GRB 250305A: AstroSat CZTI detection
  7. EP250302a:Xinglong optical observations
  8. GRB 250306A: AstroSat CZTI detection
  9. Fermi trigger No 762963055: Global MASTER-Net observations report
  10. Fermi Gamma-ray Burst Monitor trigger 762963055/250306591 is not a GRB
  11. Swift GRB 250306A: Global MASTER-Net observations report
  12. LIGO/Virgo/KAGRA S250207bg: Update-5 NED Galaxies in the Localization Volume
  13. GRB 250306A: Swift detection of a burst
  14. LIGO/Virgo/KAGRA S250207bg: Updated Sky localization
  15. GRB250101A: Radio upper limits from VLA observations
  16. LIGO/Virgo/KAGRA S250306ej: Retraction of GW compact binary merger candidate
  17. GRB 250305A: SVOM/GRM observation of a burst
  18. The EP-WXT trigger 01709132323 is likely a flaring star
  19. EP250304A: Upper limits from Fermi-GBM Observations
  20. Fermi GRB 250305A: Global MASTER-Net observations report
  21. Fermi-LAT Gamma-ray Observations of IceCube-250302A
  22. GRB 250305A: Fermi GBM Final Real-time Localization
  23. EP250302a: Optical Observations at CrAO and SAO RAS
  24. GRB 250219A: SVOM/C-GFT optical upper limit at early phase
  25. EP 250304A: Optical counterpart detection by LCO
  26. EP250302A: 1.3m DFOT optical afterglow detection
  27. IceCube-250302A: Upper limits from a search for additional neutrino events in IceCube
  28. EP250304a: refined analysis of the EP-WXT and EP-FXT observations
  29. Konus-Wind detection of GRB 250222A
  30. EP250304a: REM NIR upper limits
  31. IPN triangulation of GRB 250222A
  32. EP250304a: Swift/UVOT detection of an optical counterpart with a rising light curve
  33. EP250302a: Mondy Continued Optical Observations
  34. EP250304a: VLT/X-shooter redshift z = 0.200
  35. EP250304a: Swift-XRT detection of a fading X-ray source
  36. EP250304a: TRT optical counterpart detection
  37. LIGO/Virgo/KAGRA S250304cb: Identification of a GW compact binary merger candidate
  38. EP250304a: Global MASTER-Net observations report
  39. EP250304a: Einstein Probe detection of an X-ray transient
  40. The EP-WXT trigger 01709132212 is not a real source
  41. EP250302a: SVOM/VT optical observation
  42. LIGO/Virgo/KAGRA S250223dk and Swift/BAT-GUANO ID 762004910: Swift/UVOT Upper Limits
  43. EP250302a: SAO RAS optical observations
  44. EP250302a : GIT optical follow-up
  45. EP250302a: VLT/X-shooter redshift confirmation
  46. EP250225a: the candidate optical counterpart is an AGN
  47. EP250302a: Kinder optical follow-up observations
  48. LIGO/Virgo/KAGRA S250302av: 2 counterpart neutrino candidate events from an IceCube neutrino search
  49. EP250302a: Swift/UVOT detection
  50. EP250302a: NUTTelA-TAO Early Measurments
  51. EP250302a: optical observation from the INAF Asiago Observatory
  52. EP250302a: REM NIR upper limits
  53. IceCube-241113A: MASTER flaring blazar 5BZB J1311+0853 with Zhirkov effect
  54. EP250302a: Mondy Observations and Optical Light Curve
  55. EP250302a: VLT/MUSE optical redshift z = 1.131
  56. INTEGRAL: end of scientific operations
  57. EP250302A: VLT near-infrared observations
  58. EP250302A: VLT/X-shooter tentative redshift
  59. EP250302a: OHP/T193 optical and spectroscopic observations
  60. EP250302a: Global MASTER-Net observations report
  61. EP250302a: Xinglong F60B optical observation
  62. EP250302a: Swift-XRT observations of a fading X-ray source
  63. EP250302a: Einstein Probe detection of an X-ray transient
  64. EP250302a: SVOM/C-GFT optical observations
  65. GRB 250226A: GRANDMA Optical Observations
  66. EP250302a: Montarrenti Observatory optical detection
  67. Fermi GRB 250302A: Global MASTER-Net observations report
  68. EP250302a: FTW optical and NIR detection
  69. EP250302a: Nanshan/HMT optical counterpart detection
  70. IceCube-250302A - IceCube observation of a high-energy neutrino candidate track-like event
  71. GRB 250302A: Fermi GBM Final Real-time Localization
  72. GRB 250228A: Fermi GBM Final Localization
  73. The EP-WXT trigger 01709132140 is likely a flaring star
  74. LIGO/Virgo/KAGRA S250206dm: early X-ray upper limits from Einstein Probe WXT and preliminary results of FXT observations
  75. GRB 250225B: VLT near-infrared afterglow confirmation
  76. EP250228a: Optical observations with Kinder and Swift/UVOT
  77. Konus-Wind detection of GRB 250226A
  78. GRB 250225B: EIRSAT-1 GMOD Detection
  79. GRB 250226A: KAO Optical Upper Limit
  80. GRB 250226A: AbAO AS-32 Optical Upper Limit
  81. EP250227a: Global MASTER-Net observations report
  82. EP250223A: Upper limits from Fermi-GBM Observations
  83. EP250227a: TRT optical upper limit
  84. GRB 250225B: VLT/HAWKI near-infrared observations
  85. EP250227a: Optical upper limits with Kinder observations
  86. EP250227a: NOT optical observations
  87. EP250227a: Einstein Probe detected of a fast X-ray transient
  88. EP250228a: updates on the EP observations
  89. GRB 250226A: Fermi GBM Observation
  90. EP250225a: EP-FXT follow-up observation
  91. EP250223a: J band upper limit by SYSU 80cm telescope
  92. EP250228a: Swift/XRT localisation
  93. EP250228a: Global MASTER-Net observations report
  94. EP250228a: Einstein Probe detection of an X-ray transient
  95. GRB 250226A / EP250226a: LCO detection of the afterglow
  96. LIGO/Virgo/KAGRA S250227e: Updated Sky localization
  97. LIGO/Virgo/KAGRA S250226dl: Updated Sky localization
  98. GRB 250225B: VLT/Xshooter imaging
  99. GRB 250205A / EP250205A: further radio observations with the VLA
  100. GRB 250226B: INTEGRAL SPI-ACS and PICsIT detection

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