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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"

11789 results found.

  1. GRB 250416C / EP250416a: SVOM/GRM observation of a burst
  2. GRB 250419A: LCO optical afterglow multi-band observations
  3. GRB 250419A: MASTER optical afterglow observation
  4. Fermi-LAT Gamma-ray Observations of IceCube-250416A
  5. GRB 250419A: Swift-XRT refined Analysis
  6. Konus-Wind detection of GRB 250416C (a counterpart of EP250416a)
  7. EP250416a: refined EP-WXT and EP-FXT analysis
  8. Konus-Wind detection of GRB 250403A
  9. IceCube-250416A: DDOTI Optical Observations
  10. EP250416a: GSP optical upper limit
  11. EP250416a: Global MASTER-Net observations report
  12. EP250416a: Einstein Probe detection of an X-ray transient
  13. IceCube-250416A: Global MASTER-Net observations report
  14. GRB 250413A: AstroSat CZTI detection
  15. GRB 250412A: AstroSat CZTI detection
  16. EP250404a: Nanshan 0.43m Telescope optical observatios
  17. Fermi trigger No 766148493: Global MASTER-Net observations report
  18. Fermi trigger No 766173972: Global MASTER-Net observations report
  19. Fermi GRB 250411A: Global MASTER-Net observations report
  20. GRB 250320B: cubesat Avion detection
  21. Fermi-LAT gamma-ray observations of IceCube-250406A
  22. Konus-Wind detection of GRB 250407A
  23. GRB 250407A: EP-WXT afterglow detection
  24. GRB 250407A: COLIBRÍ/DDRAGO Detection of the Optical Counterpart
  25. GRB 250407A: Fermi GBM Detection
  26. GRB 250407A: Swift-XRT afterglow detection
  27. Fermi GRB 250407A: Global MASTER-Net observations report
  28. GRB 250407A: SRG/ART-XC afterglow detection
  29. LIGO/Virgo/KAGRA S250331o: Upper limits from Swift/BAT-GUANO
  30. Konus-Wind detection of GRB 250406B (short/hard)
  31. GRB 250406A: AstroSat CZTI detection
  32. Fermi trigger No 765663719: Global MASTER-Net observations report
  33. Fermi GRB 250406A: Global MASTER-Net observations report
  34. EP250404a / GRB 250404A: Montarrenti Observatory optical observations
  35. EP250404a / GRB 250404A: J band observations by SYSU 80cm telescope
  36. Konus-Wind detection of GRB 250404A / EP250404a
  37. EP250404a: refined analysis of the EP-WXT and EP-FXT observations
  38. GRB 250404A / EP250404a: Leavitt Observatory optical counterpart detection
  39. GRB 250404B: AstroSat CZTI detection of a short burst
  40. GRB 250403A: AstroSat CZTI detection
  41. EP250404a: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  42. EP250404a: LCO optical counterpart detection
  43. Fermi GRB 250404A: Global MASTER-Net observations report
  44. EP250404a: Xinglong decaying optical counterpart
  45. EP250404a: Global MASTER-Net observations report
  46. EP250404a: AKO Optical Afterglow Detection
  47. EP250404a: LAST detection of optical counterpart
  48. GRB 250402A: Swift/BAT-GUANO localization skymap of a burst
  49. EP250404a: Mephisto multi-band optical detection
  50. EP250321A: J band upper limit by SYSU 80cm telescope
  51. EP250404a: BOOTES-4/JGT optical afterglow detection
  52. EP250404a: Nanshan/HMT optical counterpart detection
  53. EP250404a: Einstein Probe detection of an X-ray transient
  54. IceCube-250330A: MASTER detection of PKS 2032+107 blazar flare with Zhirkov effect
  55. GRB 250402A: EP-FXT afterglow detection
  56. GRB 250322A: 10 GHz VLA radio upper limits
  57. GRB 250403A: GOTO optical counterpart follow-up observations
  58. GRB 250403A : SVOM detection of a burst
  59. GRB 250402B: AstroSat CZTI detection of a short burst
  60. GRB 250331C: Calapai Observatory, Massa S. Giorgio (Messina), upper limit
  61. GRB 250331D: Fermi GBM observation
  62. GRB 250328A: AbAO AS-32 Optical Observations
  63. GRB 250322B: GRBAlpha detection
  64. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Epoch 2)
  65. Fermi GRB 250331D: Global MASTER-Net observations report
  66. GRB 250329A: AbAO, Mondy and SAO RAS optical upper limits
  67. Konus-Wind detection of GRB 250327B
  68. LIGO/Virgo/KAGRA S250331o: NED Galaxies in the 3-Initial Localization Volume
  69. LIGO/Virgo/KAGRA S250328ae: Swift XRT observations, 34 possible X-ray sources
  70. Fermi-LAT gamma-ray observations of IceCube-250330A
  71. GRB 250331A: MAXI/GSC detection
  72. Fermi GRB 250330B: Global MASTER-Net observations report
  73. IceCube Alert 250330.35: Global MASTER-Net observations report
  74. GRB 250329B: Swift-XRT afterglow detection
  75. Swift GRB250330.26: Global MASTER-Net observations report
  76. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Epoch 1)
  77. GRB 250329A: SVOM detection of a burst
  78. LIGO/Virgo/KAGRA S250328ae: NED Galaxies in the 4-Update Localization Volume
  79. EP250302a: SPI-ACS/INTEGRAL Upper Limit
  80. GRB 250327B: Swift-XRT detection of the X-ray afterglow
  81. GRB 250327A: Swift-XRT refined Analysis
  82. FRB 20250316A: The sub-arcsecond localization of FRB 20250316A using CHIME/FRB Outriggers coincides with reported X-ray counterparts
  83. Konus-Wind detection of GRB 250322A (short)
  84. IPN triangulation of GRB 250322B
  85. Swift follow-up observations of FRB250316A and EP J120944.2+585060
  86. GRB 250322B: NuSTAR detection of the prompt emission and regular dips during the burst
  87. GRB 250322A: AstroSat CZTI detection of a short burst
  88. GRB 250322B: AstroSat CZTI detection of a bright long burst
  89. GRB 250322A: NOT optical upper limits
  90. GRB 250321B: SVOM/COLIBRÍ (F-GFT) follow-up observations
  91. EP250321a: refined analysis of the EP-WXT and EP-FXT observations
  92. GRB 250320B: NuSTAR detection of the prompt emission from two broad bursts and preliminary analysis
  93. GRB 250320A: NuSTAR Detection of the Prompt Emission and Preliminary Results
  94. GRB 250320B: Fermi GBM Observation
  95. GRB 250320B: Fermi-LAT detection
  96. GRB 250320B: AstroSat CZTI detection
  97. Swift GRB 250321A: Global MASTER-Net observations report
  98. Fermi GRB 250321A: Global MASTER-Net observations report
  99. EP250226a/GRB 250226A: KAIT optical observations
  100. GRB 250320B: Fermi GBM Final Real-time Localization

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