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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"

28235 results found.

  1. EP240506a: TRT optical upper limit
  2. LIGO/Virgo/KAGRA S240507p: Updated Sky localization and EM Bright Classification
  3. LIGO/Virgo/KAGRA S240422ed: Upper limits from a two-week IceCube neutrino search
  4. EP240506a: Optical upper limit with Kinder observations
  5. IPN triangulation of GRB 240504A
  6. GRB 240502A: 1.3m DFOT Optical upper limit
  7. EP240506a: EP-WXT detection of a new fast X-ray transient
  8. LIGO/Virgo/KAGRA S240507p: Identification of a GW compact binary merger candidate
  9. LIGO/Virgo/KAGRA S240422ed: Additional WINTER near-infrared J-band observations
  10. GRB 240504A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  11. LIGO/Virgo/KAGRA S240505av: Updated Sky localization and EM Bright Classification
  12. LIGO/Virgo/KAGRA S240505av: Identification of a GW compact binary merger candidate
  13. Fermi trigger No 736461232: Global MASTER-Net observations report
  14. GW170817: VLA observations at ~5.5 yrs since merger
  15. GRB 240504A: BALROG localization (Fermi Trigger 736492377 / GRB 240504217)
  16. GRB 240502A: Fermi GBM Observation
  17. GRB 240415A 1.3m DFOT Optical upper limit
  18. LIGO/Virgo/KAGRA S240501an: Updated Sky localization and EM Bright Classification
  19. LIGO/Virgo/KAGRA S240430ca: Updated Sky localization and EM Bright Classification
  20. GRB 240426A: VZLUSAT-2 detection
  21. GRB 240425A: VZLUSAT-2 detection
  22. MeerKAT Discovery of a Probable Radio Counterpart to EP240414a
  23. GRB 240501B: AstroSat CZTI detection
  24. GRB 240501A: Fermi GBM Final Real-time Localization
  25. GRB 240408B: VZLUSAT-2 detection
  26. GRB 240407A: VZLUSAT-2 detection
  27. LIGO/Virgo/KAGRA S240501an: Identification of a GW compact binary merger candidate
  28. LIGO/Virgo/KAGRA S240430ca: Updated Sky localization and EM Bright Classification
  29. LIGO/Virgo/KAGRA S240430ca: Identification of a GW compact binary merger candidate
  30. LIGO/Virgo/KAGRA S240422ed: GECKO/7DT ToO observations
  31. Additional DECam GW-MMADS Candidates from three nights of observations
  32. Fermi-LAT gamma-ray observations of IceCube-240424A
  33. LIGO/Virgo/KAGRA S240426s: Updated Sky localization
  34. LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limit for EP240426a
  35. LIGO/Virgo/KAGRA S240426dl: Updated Sky localization
  36. LIGO/Virgo/KAGRA S240428dr: Updated Sky localization
  37. LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet ToO observations
  38. LIGO/Virgo/KAGRA S240428dr: Identification of a GW compact binary merger candidate
  39. LIGO/Virgo/KAGRA S240422ed: J-band non-detection of J-GEM24a
  40. LIGO/Virgo/KAGRA S240422ed: DDOTI Optical Upper Limit for J-GEM24a
  41. EP240426b: AST3-2 optical upper limit
  42. LIGO/Virgo/KAGRA S240422ed: Observations with 1.6m Mephisto
  43. LIGO/Virgo S240422ed: Swift XRT observation of EP240426a
  44. LIGO/Virgo/KAGRA S240422ed: NOT optical observations of EP240426a
  45. EP240426b: EP-WXT detection of a new fast X-ray transient
  46. LIGO/Virgo/KAGRA S240422ed: Archival radio detection of EP240426a
  47. LIGO/Virgo/KAGRA S240422ed: Swope Follow-up of AT2024hfq, AT2024hfr, AT2024hfs, and AT2024hfx
  48. LIGO/Virgo/KAGRA S240422ed: BOOTES-6/DPRT optical upper limits for EP240426a
  49. LIGO/VIRGO/KAGRA S240422ed: Historical variability for EP240426a
  50. GRB 240426A: AstroSat CZTI detection
  51. XMM-Newton observation of EP240426a
  52. LIGO/Virgo/KAGRA S240426dl: Identification of a GW compact binary merger candidate
  53. GRB 240414A: NOEMA detection
  54. LIGO/Virgo/KAGRA S240422ed: EP240426a possible optical detection
  55. EP240426a: GMG optical upper limit
  56. LVK S240422ed: Further Swift-XRT followup of three sources
  57. LIGO/Virgo/KAGRA S240426s: Identification of a GW compact binary merger candidate
  58. IceCube-240424A: Upper limits from a search for additional neutrino events in IceCube
  59. LIGO/Virgo/KAGRA S240422ed: PRIME near-infrared observations
  60. LIGO/Virgo/KAGRA S240422ed: 2.5m PRL Telescope follow-up of the Swift/XRT source S240422ed_X190
  61. LIGO/Virgo/KAGRA S240422ed: Second night Pan-STARRS observations of the skymap
  62. LIGO/Virgo/KAGRA S240422ed: Further near-infrared observations with Subaru/MOIRCS by J-GEM Collaboration
  63. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-FXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
  64. LIGO/Virgo/KAGRA S240422ed: Upper limits from GECAM Observations
  65. LIGO/Virgo/KAGRA S240422ed: No significant candidates in GRANDMA and Kilonova-Catcher galaxy targeting observations
  66. LIGO/Virgo/KAGRA S240422ed: Additional DECam GW-MMADS Candidates from the first two nights of observations
  67. LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limits for Swift/XRT candidates
  68. GRB 240419B: Swift-BAT refined analysis
  69. GRB 240421B: Swift-BAT refined analysis
  70. GRB 240422A: Glowbug gamma-ray detection
  71. LIGO/Virgo/KAGRA S240422ed: Archival BlackGEM/MeerLICHT detections of AT 2024hdr & AT 2024hdq
  72. LIGO/Virgo/KAGRA S240422ed: Himalayan Chandra Telescope follow-up of the Swift/XRT source S240422ed_X101
  73. LIGO/Virgo/KAGRA S240422ed: No significant counterpart candidates in HAWC observations
  74. LIGO/Virgo/KAGRA S240422ed: No significant candidates in GRANDMA/FRAM Observations
  75. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
  76. LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
  77. LIGO/Virgo/KAGRA S240422ed: Early X-ray Upper Limits from EP-WXT for the LVK Sky Localization Region
  78. LIGO/Virgo/KAGRA S240422ed: J-band non-detection of Mag24a
  79. LIGO/Virgo/KAGRA S240422ed: Continued Imaging of Mag24a
  80. LIGO/Virgo/KAGRA S240422ed: Archival DECaPSs2 observations of the field of Mag24a
  81. LIGO/Virgo/KAGRA S240422ed: NOT J-band upper limit on the Swift/XRT source S240422ed_X61
  82. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Three Potential Electromagnetic Counterparts Reported So Far
  83. LIGO/Virgo/KAGRA S240422ed: Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
  84. LIGO/Virgo/KAGRA S240422ed: WINTER J-band upper limits on the Swift/XRT source S240422ed_X61
  85. IceCube-240419A: Upper limits from a search for additional neutrino events in IceCube
  86. LIGO/Virgo/KAGRA S240421ar: Updated Sky localization
  87. LIGO/Virgo/KAGRA S240422ed: GW-MMADS DECam upper limits on the Swift/XRT source S240422ed_X61
  88. LIGO/Virgo/KAGRA S240422ed: no candidate counterparts from Pan-STARRS observations of the skymap
  89. LIGO/Virgo/KAGRA S240422ed: No Counterparts in DDOTI/OAN Optical Observations
  90. GRB 240419A: Swift-BAT refined analysis
  91. GRB 240418A: Swift-BAT refined analysis
  92. LXT240402A/GRB240402B: Chandra X-ray detection
  93. LIGO/Virgo/KAGRA S240422ed: no candidate counterparts from ATLAS observations
  94. LIGO/Virgo/KAGRA S240422ed: WINTER near-infrared J-band observations
  95. LIGO/Virgo S240422ed: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  96. LIGO/Virgo/KAGRA S240422ed: GW-MMADS DECam observations
  97. LIGO/Virgo/KAGRA S240422ed: Updated NED Galaxies in the Localization Volume
  98. LIGO/Virgo/KAGRA S240422ed: AstroSat CZTI non-detection and upper limits
  99. LIGO/Virgo/KAGRA S240422ed: Upper limits from Fermi-GBM Observations
  100. LIGO/Virgo/KAGRA S240422ed: Updated Sky localization and EM Bright Classification

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