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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"

4055 results found.

  1. LIGO/Virgo G268556: VERITAS Very-High-Energy Gamma-Ray Observations
  2. LIGO/Virgo G284239: DLT40 follow-up observation
  3. LIGO/Virgo G277583: UH88/SNIFS classification of ATLAS and PS1 transients
  4. AXP CXOU J164710.2-455216: Fermi GBM observation
  5. LIGO/Virgo G275404 and G275659: SkyMapper Follow-up Observations
  6. LIGO/Virgo G284239: Konus-Wind observations
  7. LIGO/Virgo G284239: H.E.S.S. very-high energy gamma-ray follow-up
  8. LIGO/Virgo G284239: MAXI/GSC observations
  9. LIGO/Virgo G284239: AstroSat CZTI upper limits
  10. LIGO/Virgo G284239:SVOM/Mini-GWAC observations of the initial skymap
  11. LIGO/VIRGO G284239: Fermi GBM Upper Limits
  12. LIGO/Virgo G284239: HAWC follow-up
  13. LIGO/Virgo G284239: MASTER automatic follow up and synchronous observations
  14. LIGO/Virgo G284239: Fermi-LAT search for a high-energy gamma-ray counterpart
  15. LIGO/Virgo G284239: TZAC TAROT network observations with TRE/TCA/TCH
  16. LIGO/Virgo: G284239 ANTARES search
  17. LIGO/Virgo G284239: Swift/BAT data search
  18. LIGO/Virgo G284239: AGILE GRID observations
  19. LIGO/Virgo G284239: INTEGRAL search for a prompt gamma-ray counterpart
  20. LIGO/Virgo G284239: AGILE MCAL Observations
  21. LIGO/Virgo G284239: IceCube neutrino observations
  22. LIGO/Virgo G284239: Identification of a GW Burst Candidate
  23. LIGO/Virgo G268556: Refined localization from CBC parameter estimation
  24. LIGO/Virgo G275404: DLT40 follow-up observation
  25. LIGO/Virgo G277583: DLT40 follow-up observation
  26. LIGO/Virgo G275697: Update on significance from offline analyses
  27. LIGO/Virgo G275404: Update on significance from offline analyses
  28. LIGO/Virgo G275404: European VLBI Network (EVN) follow-up of the near-IR transient in the AGL J1914+1043 field
  29. LIGO/Virgo G275697: LOFAR follow-up
  30. LIGO/Virgo G277583: Konus-Wind observations
  31. LIGO/Virgo G277583: Fermi GBM Observations
  32. LIGO/Virgo G277583: INTEGRAL search for an X-ray and gamma-ray counterpart
  33. LIGO/Virgo G275697: AMI Large Array Search for a Radio Afterglow
  34. IPN Triangulation of GRB 170320A (long/intense)
  35. LIGO/Virgo G277583: CALET Observations
  36. LIGO/Virgo G277583: Asiago spectroscopic classification of ATLAS17byo and ATLAS17cgg
  37. LIGO/Virgo G277583 : MAXI/GSC observations
  38. LIGO/Virgo G275404: P200/DBSP Classification of iPTF Candidates
  39. LIGO/Virgo G277583: P200/DBSP Classification of ATLAS Candidates
  40. LIGO/Virgo G277583: AstroSat CZTI upper limits
  41. LIGO/Virgo G275697: Swift-XRT source 23 no longer fading
  42. LIGO/Virgo G277583: Swift/BAT data search
  43. LIGO/Virgo G277583: Discovery Channel Telescope Follow-Up of ATLAS17cck
  44. LIGO/Virgo G277583: ATLAS coverage and transients over the first 2 days
  45. LIGO/Virgo G277583: ATLAS17cck is likely a minor planet
  46. LIGO/Virgo G277583: GROND follow up of ATLAS17cck
  47. LIGO/Virgo G277583: ATLAS17cck - a fast declining transient
  48. LIGO/Virgo G275697: DLT40 follow-up observation
  49. LIGO/Virgo G274296: DLT40 follow-up observation
  50. LIGO/Virgo G275697: Fermi-LAT search for a high-energy gamma-ray counterpart
  51. LIGO/Virgo G277583: ERRATUM LV GCN 20871: TAROT Calern (TCA) observations
  52. LIGO/Virgo G277583: TAROT Calern (TCA) observations
  53. LIGO/Virgo G277583: SVOM/Mini-GWAC observations of the initial skymap
  54. LIGO/Virgo G275404: Medicina radio follow-up of near-infrared
  55. LIGO/Virgo G277583: INTEGRAL was inactive at the time of the event
  56. LIGO/Virgo G277583 ANTARES search
  57. LIGO/Virgo G277583: AGILE GRID observations
  58. LIGO/Virgo G277583: AGILE MCAL observations
  59. LIGO/Virgo G270580: optical observations and classification of PS and MASTER sources
  60. LIGO/Virgo G277583: IceCube neutrino observations
  61. LIGO/Virgo G277583: Identification of a GW Burst Candidate
  62. IPN Triangulation of GRB 170311B (long/very intense)
  63. LIGO/Virgo G275697: GRAWITA NOT optical observations of Swift/XRT Source 23
  64. SN MASTER OT J042250.16-820415.4 is the possible optical counterpart of the gravitational waves event LIGO/Virgo G274296
  65. LIGO/Virgo G275404: Swift-XRT observations of sources in the AGILE error region
  66. LIGO/Virgo G275697: Swift-XRT source 23 is fading
  67. LIGO/Virgo G275404: Updated localization from LIGO data
  68. LIGO/Virgo G275404 and AGL J1914+1043: INTEGRAL follow-up
  69. LIGO/Virgo G275697: Updated localization from LIGO data
  70. LIGO/Virgo G275697: Further Swift-XRT sources
  71. LIGO/Virgo G275697: P200/DBSP Classification of iPTF Candidates
  72. LIGO/Virgo G275404: P200/DBSP Classification of iPTF Candidates
  73. LIGO/Virgo G275697: Liverpool Telescope classification of EM candidates
  74. LIGO/Virgo G275404: Liverpool Telescope classification of EM candidates
  75. LIGO/Virgo G275697: Further Swift-XRT sources
  76. LIGO/Virgo G275404: HAWC follow-up
  77. LIGO/Virgo G275404: PIRATE Observations
  78. LIGO/Virgo G275404: Liverpool Telescope classification of EM candidates
  79. LIGO/Virgo G275697: Liverpool Telescope classification of EM candidates
  80. LIGO/Virgo G275697: Further Swift-XRT sources
  81. LIGO/Virgo G275697: MAXI/GSC observations
  82. LIGO/Virgo G275697: Additional iPTF Optical Transient Candidates
  83. LIGO/Virgo G275404: Additional iPTF Optical Transient Candidates
  84. LIGO/Virgo G275404: Nearby Galaxies in the Localization Volume
  85. LIGO/Virgo G275697: Further Swift-XRT sources
  86. LIGO/Virgo G275697: Fermi GBM Upper Limits
  87. LIGO/Virgo G275697: AstroSat CZTI upper limits
  88. LIGO/Virgo G275697: optical spectroscopy of Swift/XRT source 1
  89. LIGO/Virgo G268556, G270580, G274296, and G275404: Konus-Wind observations
  90. LIGO/Virgo G275697: SVOM/Mini-GWAC observations of the initial skymap
  91. LIGO/Virgo G275697: iPTF Optical Transient Candidates
  92. LIGO/Virgo G275404: iPTF Optical Transient Candidates
  93. LIGO/Virgo G275404: Fermi GBM Upper Limits
  94. LIGO/Virgo G275404: A near-infrared transient in the error circle of AGL J1914+1043
  95. LIGO/Virgo G275697: CALET Observations
  96. LIGO/Virgo G275697: MASTER automatic follow up detection
  97. LIGO/Virgo G275697: CNEOST optical observations
  98. LIGO/Virgo G274296 and G275404 : MAXI/GSC observations
  99. LIGO/Virgo G275404: Nearby galaxy observations by J-GEM collaboration
  100. LIGO/Virgo G275404: Nearby Galaxies in the Localization Region

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