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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"

3615 results found.

  1. LIGO/Virgo S190930t and S190930s: MASTER OT J205529.78+220725.5/AT2019rpr further analysis
  2. LIGO/Virgo S190930t: Upper limits on the two of the ZTF/GROWTH candidates
  3. LIGO/Virgo S190828h: Updated Sky Localization
  4. LIGO/Virgo S190814bv: VLA 6 GHz observations of 75 galaxies in the 90% localization region
  5. LIGO/Virgo S190923y: optical spectrum of MASTER detected transient
  6. LIGO/Virgo S190930t: Transient found in Swift/UVOT counterpart search
  7. LIGO/Virgo S190930t and S190930s: MASTER PSN in unknown disk galaxy
  8. LIGO/Virgo S190930t: Candidates from the Zwicky Transient Facility
  9. LIGO/Virgo S190930t: No counterpart candidates in Fermi-LAT observations
  10. LIGO/Virgo S190930t and S190930s: MASTER optical observation and optical transient
  11. LIGO/Virgo S190930s: No counterpart candidates in Fermi-LAT observations
  12. LIGO/Virgo S190930t: Upper limits from CALET observations.
  13. LIGO/Virgo S190930s: Upper limits from CALET observations.
  14. LIGO/Virgo S190930t: Coverage and upper limits from MAXI/GSC observations
  15. LIGO/Virgo S190930s: no counterpart candidates in the Swift/BAT observations
  16. LIGO/Virgo S190930t: no counterpart candidates in the Swift/BAT observations
  17. LIGO/Virgo S190930t: Upper limits from Fermi-GBM Observations
  18. LIGO/Virgo S190930s: Upper limits from Fermi-GBM Observations
  19. LIGO/Virgo S190930t: No counterpart candidates in HAWC observations
  20. LIGO/Virgo S190930s: no counterpart candidates in AGILE-GRID observations
  21. LIGO/Virgo S190928c: Retraction of GW unmodeled transient candidate
  22. LIGO/Virgo S190930t : no neutrino counterpart candidate in ANTARES search
  23. LIGO/Virgo S190930s : no neutrino counterpart candidate in ANTARES search
  24. LIGO/Virgo S190930t: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  25. LIGO/Virgo S190930s: No counterpart candidates in AGILE-MCAL observations
  26. LIGO/Virgo S190930s: Coverage and upper limits from MAXI/GSC observations
  27. LIGO/Virgo S190930t: Identification of a GW compact binary merger candidate
  28. LIGO/Virgo S190930t: Global MASTER-Net observations report
  29. LIGO/Virgo S190930t: Upper limits from IceCube neutrino searches
  30. LIGO/Virgo S190930s: Upper limits from IceCube neutrino searches
  31. LIGO/Virgo S190930s: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  32. LIGO/Virgo S190930s: Identification of a GW compact binary merger candidate
  33. LIGO/Virgo S190930s: Global MASTER-Net observations report
  34. LIGO/Virgo S190828j: Updated Sky Localization
  35. LIGO/Virgo S190923y: MASTER OT outburst detection inside NSBH merger error-box
  36. LIGO/Virgo S190923y: No significant candidates in TAROT-GRANDMA observations
  37. LIGO/Virgo S190923y: no counterpart candidates in the Swift/BAT observations
  38. LIGO/Virgo S190924h: No counterpart candidates in Fermi-LAT observations
  39. LIGO/Virgo S190924h: Not observable by CALET
  40. LIGO/Virgo S190924h: no counterpart candidates in the Swift/BAT observations
  41. LIGO/Virgo S190923y: No neutrino candidates at Pierre Auger Observatory
  42. LIGO/Virgo S190924h: Upper limits from Fermi-GBM Observations
  43. LIGO/Virgo S190924h: no counterpart candidates in AGILE-GRID observations
  44. LIGO/Virgo S190924h: No counterpart candidates in AGILE-MCAL observations
  45. LIGO/Virgo S190924h: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  46. LIGO/Virgo S190924h : no neutrino counterpart candidate in ANTARES search
  47. LIGO/Virgo S190924h: Coverage and upper limits from MAXI/GSC observations
  48. LIGO/Virgo S190923y: No counterpart candidates in Fermi-LAT observations
  49. LIGO/Virgo S190924h: Global MASTER-Net observations report
  50. LIGO/Virgo S190923y: Upper limits from CALET observations.
  51. LIGO/Virgo S190924h: Identification of a GW compact binary merger candidate
  52. LIGO/Virgo S190924h: Upper limits from IceCube neutrino searches
  53. LIGO/Virgo S190923y: INTEGRAL IBIS coded-masked imaging observations of part of the localization area and further all-sky upper limits
  54. LIGO/Virgo S190923y: Upper limits from Fermi-GBM Observations
  55. LIGO/Virgo S190814bv: Chandra X-ray non-detection of ASKAP J005547-270433 / AT2019osy
  56. LIGO/Virgo S190923y: Upper limits from AGILE-GRID observations
  57. LIGO/Virgo S190923y: No counterpart candidates in AGILE-MCAL observations
  58. LIGO/Virgo S190923y: Coverage and upper limits from MAXI/GSC observations
  59. LIGO/Virgo S190923y : no neutrino counterpart candidate in ANTARES search
  60. LIGO/Virgo S190923y: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  61. LIGO/Virgo S190923y: Identification of a GW compact binary merger candidate
  62. LIGO/Virgo S190923y: No counterpart candidates in HAWC observations
  63. LIGO/Virgo S190923y: Global MASTER-Net observations report
  64. LIGO/Virgo S190923y: Upper limits from IceCube neutrino searches
  65. LIGO/Virgo S190814bv: HST and ALMA observations of the host galaxy of ASKAP J005547-270433 / AT 2019osy
  66. LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019nte host galaxy
  67. LIGO/Virgo S190828l: Updated Sky Localization
  68. LIGO/Virgo S190915ak: No significant candidates in TAROT-GRANDMA observations
  69. LIGO/Virgo S190910h: No significant candidates in TAROT-GRANDMA observations
  70. LIGO/Virgo S190910h: Updated Sky Localization
  71. NASA GW-EM Community Survey
  72. LIGO/Virgo S190915ak: Updated Sky Localization
  73. LIGO/Virgo S190915ak: No transient candidates in CALET observations
  74. LIGO/Virgo S190915ak: no counterpart candidates in the Swift/BAT observations
  75. LIGO/Virgo S190915ak: Upper limits from Fermi-GBM Observations
  76. LIGO/Virgo S190915ak: No counterpart candidates in Fermi-LAT observations
  77. LIGO/Virgo S190915ak: Coverage and upper limits from MAXI/GSC observations
  78. LIGO/Virgo S190915ak : no neutrino counterpart candidate in ANTARES search
  79. LIGO/Virgo S190915ak: Upper Limits from AGILE-GRID observations
  80. LIGO/Virgo S190915ak: No counterpart candidate in AGILE-MCAL observations
  81. LIGO/Virgo S190915ak: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  82. LIGO/Virgo S190915ak: Upper limits from IceCube neutrino searches
  83. LIGO/Virgo S190915ak: Identification of a GW compact binary merger candidate
  84. LIGO/Virgo S190915ak: Global MASTER-Net observations report
  85. LIGO/Virgo S190910d : No significant candidates in TAROT-GRANDMA observations
  86. LIGO/Virgo S190814bv: No counterpart candidate after completion of GRAWITA VST-ESO PARANAL transient survey.
  87. LIGO/Virgo S190910h: WHT spectroscopy of Gaia19ebl, Gaia19eba, Gaia19eaz
  88. LIGO/Virgo S190910h: No counterpart candidates in Fermi-LAT observations
  89. LIGO/Virgo S190910d: MASTER previous detection of Gaia19eba/AT2019qam
  90. LIGO/Virgo S190910h: Gaia Photometric Alerts transient candidates
  91. LIGO/Virgo S190910d: Gaia Photometric Alerts transient candidate
  92. LIGO/Virgo S190910d: No Counterparts in DDOTI/OAN Optical Observations
  93. LIGO/Virgo S190910h: Upper limits from CALET observations.
  94. LIGO/Virgo S190910d: No transient candidates in CALET observations.
  95. LIGO/Virgo S190910h: WHT spectroscopy of AT2019pyz/PS19fbi
  96. LIGO/Virgo S190910h and S190910d: WHT photometry of ZTF candidates
  97. LIGO/Virgo S190910h: AT2019pxi, AT2019pxj and AT2019pxn 10.4m GTC spectroscopy
  98. LIGO/Virgo S190910h: WHT spectroscopy of ZTF19abygvmp/AT2019pzg
  99. LIGO/Virgo S190910d and S190910h: No counterpart candidates in KAIT observations
  100. LIGO/Virgo S190910d: No neutrino candidates at Pierre Auger Observatory

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