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

43952 results found.

  1. IceCube Alert 250309.32: Global MASTER-Net observations report
  2. GRB 250309B: BALROG localization (Fermi Trigger 763198715 / GRB 250309318)
  3. EP250308a: Global MASTER-Net observations report
  4. EP250308a: GSP optical upper limit
  5. EP250308a: FTW optical and NIR upper limits
  6. EP250308a: Einstein Probe detection of an X-ray transient
  7. EP250308a: NOT optical upper limit
  8. GRB 250309A: Fermi GBM Final Real-time Localization
  9. GRB 250306A: EIRSAT-1 GMOD detection
  10. The EP-WXT trigger 01709132387 is likely a flaring star
  11. Fermi GRB 250307A: Global MASTER-Net observations report
  12. Konus-Wind detection of GRB 250306A
  13. GRB 250307A: Fermi GBM Final Real-time Localization
  14. GRB 250306A: Swift-BAT refined analysis
  15. GRB 250306A: NuSTAR detection of the prompt emission
  16. EP250304a: MeerKAT detection of a possible radio counterpart
  17. IceCube-241016A: MASTER flaring blazar 5BZU J073038.29-320820.2 with Zhirkov effect
  18. GRB 250305A: AstroSat CZTI detection
  19. EP250302a:Xinglong optical observations
  20. GRB 250306A: AstroSat CZTI detection
  21. Fermi trigger No 762963055: Global MASTER-Net observations report
  22. Fermi Gamma-ray Burst Monitor trigger 762963055/250306591 is not a GRB
  23. Swift GRB 250306A: Global MASTER-Net observations report
  24. LIGO/Virgo/KAGRA S250207bg: Update-5 NED Galaxies in the Localization Volume
  25. GRB 250306A: Swift detection of a burst
  26. LIGO/Virgo/KAGRA S250207bg: Updated Sky localization
  27. GRB250101A: Radio upper limits from VLA observations
  28. LIGO/Virgo/KAGRA S250306ej: Retraction of GW compact binary merger candidate
  29. GRB 250305A: SVOM/GRM observation of a burst
  30. The EP-WXT trigger 01709132323 is likely a flaring star
  31. EP250304A: Upper limits from Fermi-GBM Observations
  32. Fermi GRB 250305A: Global MASTER-Net observations report
  33. Fermi-LAT Gamma-ray Observations of IceCube-250302A
  34. GRB 250305A: Fermi GBM Final Real-time Localization
  35. EP250302a: Optical Observations at CrAO and SAO RAS
  36. GRB 250219A: SVOM/C-GFT optical upper limit at early phase
  37. EP 250304A: Optical counterpart detection by LCO
  38. EP250302A: 1.3m DFOT optical afterglow detection
  39. IceCube-250302A: Upper limits from a search for additional neutrino events in IceCube
  40. EP250304a: refined analysis of the EP-WXT and EP-FXT observations
  41. Konus-Wind detection of GRB 250222A
  42. EP250304a: REM NIR upper limits
  43. IPN triangulation of GRB 250222A
  44. EP250304a: Swift/UVOT detection of an optical counterpart with a rising light curve
  45. EP250302a: Mondy Continued Optical Observations
  46. EP250304a: VLT/X-shooter redshift z = 0.200
  47. EP250304a: Swift-XRT detection of a fading X-ray source
  48. EP250304a: TRT optical counterpart detection
  49. LIGO/Virgo/KAGRA S250304cb: Identification of a GW compact binary merger candidate
  50. EP250304a: Global MASTER-Net observations report
  51. EP250304a: Einstein Probe detection of an X-ray transient
  52. The EP-WXT trigger 01709132212 is not a real source
  53. EP250302a: SVOM/VT optical observation
  54. LIGO/Virgo/KAGRA S250223dk and Swift/BAT-GUANO ID 762004910: Swift/UVOT Upper Limits
  55. EP250302a: SAO RAS optical observations
  56. EP250302a : GIT optical follow-up
  57. EP250302a: VLT/X-shooter redshift confirmation
  58. EP250225a: the candidate optical counterpart is an AGN
  59. EP250302a: Kinder optical follow-up observations
  60. LIGO/Virgo/KAGRA S250302av: 2 counterpart neutrino candidate events from an IceCube neutrino search
  61. EP250302a: Swift/UVOT detection
  62. EP250302a: NUTTelA-TAO Early Measurments
  63. EP250302a: optical observation from the INAF Asiago Observatory
  64. EP250302a: REM NIR upper limits
  65. IceCube-241113A: MASTER flaring blazar 5BZB J1311+0853 with Zhirkov effect
  66. EP250302a: Mondy Observations and Optical Light Curve
  67. EP250302a: VLT/MUSE optical redshift z = 1.131
  68. INTEGRAL: end of scientific operations
  69. EP250302A: VLT near-infrared observations
  70. EP250302A: VLT/X-shooter tentative redshift
  71. EP250302a: OHP/T193 optical and spectroscopic observations
  72. EP250302a: Global MASTER-Net observations report
  73. EP250302a: Swift-XRT observations of a fading X-ray source
  74. EP250302a: Einstein Probe detection of an X-ray transient
  75. EP250302a: SVOM/C-GFT optical observations
  76. GRB 250226A: GRANDMA Optical Observations
  77. Fermi GRB 250302A: Global MASTER-Net observations report
  78. EP250302a: FTW optical and NIR detection
  79. EP250302a: Nanshan/HMT optical counterpart detection
  80. IceCube-250302A - IceCube observation of a high-energy neutrino candidate track-like event
  81. GRB 250302A: Fermi GBM Final Real-time Localization
  82. GRB 250228A: Fermi GBM Final Localization
  83. The EP-WXT trigger 01709132140 is likely a flaring star
  84. LIGO/Virgo/KAGRA S250206dm: early X-ray upper limits from Einstein Probe WXT and preliminary results of FXT observations
  85. EP250228a: Optical observations with Kinder and Swift/UVOT
  86. Konus-Wind detection of GRB 250226A
  87. GRB 250225B: EIRSAT-1 GMOD Detection
  88. GRB 250226A: KAO Optical Upper Limit
  89. GRB 250226A: AbAO AS-32 Optical Upper Limit
  90. EP250227a: Global MASTER-Net observations report
  91. EP250223A: Upper limits from Fermi-GBM Observations
  92. EP250227a: TRT optical upper limit
  93. GRB 250225B: VLT/HAWKI near-infrared observations
  94. EP250227a: Optical upper limits with Kinder observations
  95. EP250227a: NOT optical observations
  96. EP250227a: Einstein Probe detected of a fast X-ray transient
  97. EP250228a: updates on the EP observations
  98. GRB 250226A: Fermi GBM Observation
  99. EP250225a: EP-FXT follow-up observation
  100. EP250223a: J band upper limit by SYSU 80cm telescope

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