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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"

12170 results found.

  1. EP250404a: AKO Optical Afterglow Detection
  2. EP250404a: LAST detection of optical counterpart
  3. GRB 250402A: Swift/BAT-GUANO localization skymap of a burst
  4. EP250404a: Mephisto multi-band optical detection
  5. EP250321A: J band upper limit by SYSU 80cm telescope
  6. EP250404a: BOOTES-4/JGT optical afterglow detection
  7. EP250404a: Nanshan/HMT optical counterpart detection
  8. EP250404a: Einstein Probe detection of an X-ray transient
  9. IceCube-250330A: MASTER detection of PKS 2032+107 blazar flare with Zhirkov effect
  10. GRB 250402A: EP-FXT afterglow detection
  11. GRB 250322A: 10 GHz VLA radio upper limits
  12. GRB 250403A: GOTO optical counterpart follow-up observations
  13. GRB 250403A : SVOM detection of a burst
  14. GRB 250402B: AstroSat CZTI detection of a short burst
  15. GRB 250331C: Calapai Observatory, Massa S. Giorgio (Messina), upper limit
  16. GRB 250331D: Fermi GBM observation
  17. GRB 250328A: AbAO AS-32 Optical Observations
  18. GRB 250322B: GRBAlpha detection
  19. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Epoch 2)
  20. Fermi GRB 250331D: Global MASTER-Net observations report
  21. GRB 250329A: AbAO, Mondy and SAO RAS optical upper limits
  22. Konus-Wind detection of GRB 250327B
  23. LIGO/Virgo/KAGRA S250331o: NED Galaxies in the 3-Initial Localization Volume
  24. LIGO/Virgo/KAGRA S250328ae: Swift XRT observations, 34 possible X-ray sources
  25. Fermi-LAT gamma-ray observations of IceCube-250330A
  26. GRB 250331A: MAXI/GSC detection
  27. Fermi GRB 250330B: Global MASTER-Net observations report
  28. IceCube Alert 250330.35: Global MASTER-Net observations report
  29. GRB 250329B: Swift-XRT afterglow detection
  30. Swift GRB250330.26: Global MASTER-Net observations report
  31. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Epoch 1)
  32. GRB 250329A: SVOM detection of a burst
  33. LIGO/Virgo/KAGRA S250328ae: NED Galaxies in the 4-Update Localization Volume
  34. EP250302a: SPI-ACS/INTEGRAL Upper Limit
  35. GRB 250327B: Swift-XRT detection of the X-ray afterglow
  36. GRB 250327A: Swift-XRT refined Analysis
  37. FRB 20250316A: The sub-arcsecond localization of FRB 20250316A using CHIME/FRB Outriggers coincides with reported X-ray counterparts
  38. Konus-Wind detection of GRB 250322A (short)
  39. IPN triangulation of GRB 250322B
  40. Swift follow-up observations of FRB250316A and EP J120944.2+585060
  41. GRB 250322B: NuSTAR detection of the prompt emission and regular dips during the burst
  42. GRB 250322A: AstroSat CZTI detection of a short burst
  43. GRB 250322B: AstroSat CZTI detection of a bright long burst
  44. GRB 250322A: NOT optical upper limits
  45. GRB 250321B: SVOM/COLIBRÍ (F-GFT) follow-up observations
  46. EP250321a: refined analysis of the EP-WXT and EP-FXT observations
  47. GRB 250320B: NuSTAR detection of the prompt emission from two broad bursts and preliminary analysis
  48. GRB 250320A: NuSTAR Detection of the Prompt Emission and Preliminary Results
  49. GRB 250320B: Fermi GBM Observation
  50. GRB 250320B: Fermi-LAT detection
  51. GRB 250320B: AstroSat CZTI detection
  52. Swift GRB 250321A: Global MASTER-Net observations report
  53. Fermi GRB 250321A: Global MASTER-Net observations report
  54. EP250226a/GRB 250226A: KAIT optical observations
  55. GRB 250320B: Fermi GBM Final Real-time Localization
  56. GRB 250309B: Proof-of-concept for Joint ZTF+EP Experiment
  57. GRB 250320A: Fermi GBM Final Real-time Localization
  58. Fermi GRB 250319B: Global MASTER-Net observations report
  59. GRB 250317C: AstroSat CZTI detection
  60. GRB 250316A: Swift-XRT afterglow detection
  61. Fermi GRB 250316A: Global MASTER-Net observations report
  62. GRB 250314A: EP-FXT afterglow detection
  63. EP250315a: refined analysis of the EP-WXT and EP-FXT observations
  64. GRB 250312B: GRBAlpha detection
  65. EP250315a: Einstein Probe detection of an X-ray transient
  66. GRB 250226A: Mondy AZT-33IK and Koshka Zeiss-1000 Optical Upper Limits
  67. GRB 250314A: NOT near-infrared candidate counterpart
  68. GRB 250313A: Fermi GBM Detection
  69. GRB 250312B: Fermi GBM Observation
  70. GRB250314A: SVOM/VT lack of bright optical candidate from VHF data
  71. Konus-Wind detection of GRB 250313A
  72. Konus-Wind detection of GRB 250308A
  73. GRB 250314A: SVOM detection of a burst
  74. GRB 250313A: AstroSat CZTI detection of a bright long burst
  75. IceCube-250309A: MASTER detection of J140105.33-091631.6 blazar flare with Zhirkov effect
  76. GRB 250313A: Fermi-LAT detection
  77. GRB 250312B: Swift/BAT-GUANO localization skymap of a burst
  78. Fermi GRB 250313A: Global MASTER-Net observations report
  79. ATCA detection of the radio counterpart of GRB 250309B-AT2025dws
  80. EP250302a: Chandra X-ray Detection
  81. GRB 250312A: Swift-XRT refined Analysis
  82. Fermi trigger No 763509110: Global MASTER-Net observations report
  83. GRB 250312B: Fermi GBM Final Localization
  84. LIGO/Virgo/KAGRA S250304cb: Upper limits from Swift/BAT-GUANO
  85. GRB 250312A: Swift detection of a burst
  86. GRB 250309B: 1.3m DFOT Optical observations
  87. GRB 250308A: Swift/BAT-GUANO localization skymap of a short burst
  88. GRB 250302A: Swift/BAT-GUANO localization skymap of a burst
  89. GRB 250228A: Swift/BAT-GUANO localization skymap of a likely short burst
  90. GRB 250226B: Swift/BAT-GUANO localization skymap of a likely long GRB
  91. GRB 250226A: Swift/BAT-GUANO localization skymap of a long GRB
  92. GRB 250223B: Swift/BAT-GUANO localization skymap of a short burst
  93. GRB 250309B: PRIME near-infrared detection
  94. GRB 250311A/EP250311a: TRT optical upper limit
  95. EP250311a/GRB 250311A: EP-WXT detection
  96. GRB 250311A/MAXI J1457-026: MAXI/GSC detection
  97. Konus-Wind detection of GRB 250309B
  98. IPN triangulation of GRB 250308A (short)
  99. IceCube-241224A: MASTER detection of PKS 1217+02 blazar flare with Zhirkov effect
  100. GRB 250309B: Swift-XRT refined Analysis

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