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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

28045 results found.

  1. LIGO/Virgo S190513bm: AGILE MCAL observation
  2. LIGO/Virgo S190513bm: HAWC follow-up
  3. LIGO/Virgo S190513bm: Identification of a GW compact binary merger candidate
  4. LIGO/Virgo S190512at: Insight-HXMT/HE observation
  5. GRB 190512A: Swift-BAT refined analysis
  6. LIGO-Virgo S190512at: AGILE GRID observations
  7. LIGO/Virgo S190512at: Swift/BAT Counterpart Search
  8. LIGO/Virgo S190510g: Pan-STARRS and ATLAS observations and candidates
  9. LIGO/Virgo S190512at: ANTARES neutrino search
  10. LIGO/Virgo S190512at: Fermi-LAT search for a high-energy gamma-ray counterpart
  11. LIGO/Virgo S190512at: MAXI/GSC Observations
  12. LIGO/Virgo S190512at: Fermi GBM Observations
  13. LIGO/Virgo S190510g: Spectroscopic Classification of DECam-GROWTH and DES-GW Candidate DG19fqqk/desgw-190510c with Magellan
  14. GRB 190512A: Fermi GBM observation
  15. LIGO/Virgo S190512at: Identification of a GW compact binary merger candidate
  16. GRB 190511A: Swift-BAT refined analysis
  17. GRB 190511A: Swift-XRT refined Analysis
  18. IPN triangulation of GRB 190510A (short)
  19. LIGO/Virgo S190510g: DOAO Observation
  20. LIGO/Virgo S190510g: CALET Observations
  21. GRB 190511A: Swift/UVOT Detection
  22. LIGO/Virgo S190510g: KMTNet observation of DECam-GROWTH and DESGW candidates
  23. GRB 190511A: NOT optical afterglow
  24. LIGO/Virgo S190510g: Update on candidate significance
  25. LIGO/Virgo S190426c: VLA Follow-Up Observations of ZTF19aassfws
  26. LIGO/Virgo S190510g: GRAWITA VST-ESO PARANAL optical observations
  27. GRB 190511A: Enhanced Swift-XRT position
  28. LIGO/Virgo S190510g : Xinglong-60cm upper limit of the GRAWITA REM's OT
  29. LIGO/Virgo S190510g: Unconfirmed OT in PGC 094244
  30. LIGO/Virgo S190510g: Dabancheng/HMT Follow-Up Observations
  31. LIGO/Virgo S190510g: Xinglong/Schmidt Follow-Up Observations
  32. LIGO/Virgo S190510g: Pierre Auger Observatory follow-up
  33. GRB 190511A: Swift detection of a burst
  34. LIGO/Virgo S190510g: Insight-HXMT/HE updated observation
  35. LIGO/Virgo S190510g: SOAR/Goodman follow-up observations
  36. LIGO/Virgo S190510g: Optical Counterpart Candidates from DECam-GROWTH
  37. LIGO/Virgo S190510g: CNEOST Follow-Up Observations
  38. LIGO/Virgo S190510g: J-GEM optical/NIR follow-up observations
  39. LIGO/Virgo S190510g: Lick/KAIT Follow-Up Observations
  40. LIGO/Virgo S190510g: Updated classification and data quality report
  41. LIGO/Virgo S190510g: Fermi-LAT search for a high-energy gamma-ray counterpart
  42. LIGO-Virgo S190510g: AGILE GRID observations
  43. LIGO/Virgo S190510g: Potential host galaxies on the updated skymap from the GLADE catalog
  44. LIGO/Virgo S190510g: GRAWITA REM optical observations
  45. LIGO/Virgo S190510g: Swift/BAT Counterpart Search
  46. LIGO/Virgo S190510g: Insight-HXMT/HE observation
  47. LIGO/Virgo S190510g: HSC Y-band follow-up observation
  48. LIGO/Virgo S190510g: Updated localization from LIGO and Virgo data
  49. LIGO/Virgo S190510g: MAXI/GSC Observations
  50. LIGO/Virgo S190510g: ANTARES neutrino search
  51. LIGO/Virgo S190510g: Potential host galaxies from the GLADE catalog
  52. LIGO/Virgo S190510g: Identification of a GW compact binary merger candidate
  53. LIGO/Virgo S190510g: HAWC follow-up
  54. LIGO/Virgo S190426c: Archival VLASS Observations of ZTF19aassfws 14 days prior to Merger
  55. LIGO-Virgo S190510g: AGILE MCAL observations
  56. LIGO/Virgo S190510g: IceCube Neutrino Search
  57. GRB 190508A: GOTO optical search - no counterparts
  58. Fermi GRB190507.71 Global MASTER-Net observations report
  59. GRB 190507B: GOTO optical counterpart search
  60. LIGO/Virgo S190426c (BHNS candidate): Implications from Numerical Relativity
  61. GRB 190501A: Swift XRT and UVOT Observations
  62. LIGO/Virgo S190426c: Konus-Wind observations
  63. LIGO/Virgo S190425z: Konus-Wind observations
  64. IceCube-190504A: MASTER optical monitoring analysis
  65. Fermi Trigger 578903308 / GRB 190507270 / GRB190507A: BALROG localization
  66. LIGO/Virgo S190426c: Update on Source Classification
  67. IceCube-190504A: Insight-HXMT/HE observation
  68. GRB 190501A: CALET Gamma-Ray Burst Monitor detection
  69. IceCube-190504A: Swift-XRT Follow-up Observations
  70. IceCube-190503A: Swift-XRT Follow-up Observations
  71. Fermi-LAT Gamma-ray Observations of IceCube-190504A
  72. Search for counterpart to IceCube-190504A with ANTARES
  73. IceCube-190503A: Insight-HXMT/HE observation
  74. LIGO/Virgo S190503bf Global MASTER-Net observations report
  75. LIGO/Virgo S190503bf: Swift/BAT Counterpart Search
  76. LIGO/Virgo S190503bf: Fermi-LAT search for a high-energy gamma-ray counterpart
  77. IceCube-190503A: Insight-HXMT/HE observation
  78. LIGO/Virgo S190503bf: ANTARES neutrino search
  79. Fermi-LAT Gamma-ray Observations of IceCube-190503A
  80. LIGO/Virgo S190503bf: Fermi-GBM Observations
  81. LIGO/Virgo S190503bf: MAXI/GSC Observations
  82. LIGO/Virgo S190503bf: AGILE-GRID Observations
  83. IceCube-190503A: INTEGRAL prompt observation
  84. LIGO/Virgo S190503bf: INTEGRAL prompt observation
  85. LIGO/Virgo S190503bf: Identification of a GW compact binary merger candidate
  86. LIGO/Virgo S190421ar: Updated localization and classification from LIGO and Virgo data
  87. GRB 190501A: GOTO optical counterpart search
  88. LIGO/Virgo S190425z: Insight-HXMT observation and counterpart search
  89. LIGO/Virgo S190426c: Gaia19boq 0.6m BOOTES-5/JGT, 1.5m OSN and 10.4m GTC observations
  90. Fermi Trigger 578462495 / GRB 190502168 / GRB190502A: BALROG localization
  91. GRB 190501A: AGILE/GRID detection
  92. LIGO/Virgo S190426c: ZTF19aaslzjf, ZTF19aasmftm and ZTF19aasmddt 1.5m OSN and 10.4m GTC observations
  93. LIGO/Virgo S190425z: Gaia Photometric Alerts transient candidates
  94. LIGO/Virgo S190426c: Swift rapid follow-up observations of S190425z and S190426c and URL for observation log for all future events
  95. LIGO/Virgo S190426c: GROWTH India follow-up of GRAWITA transient
  96. LIGO/Virgo S190412m: Further J-GEM optical/NIR observations
  97. LIGO/Virgo S190425z: 1.3-m optical imaging of UVOT transient field
  98. LIGO/Virgo S190426c: Fermi-LAT search for a high-energy gamma-ray counterpart
  99. LIGO/Virgo S190426c: MASTER analysys of GRAWITA transients
  100. LIGO/Virgo S190426c: GRAWITA transients from Asiago Schmidt wide field observations

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