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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"

4067 results found.

  1. LIGO/Virgo S200311bg: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  2. LIGO/Virgo S200311bg: Upper limits from IceCube neutrino searches
  3. LIGO/Virgo S200311bg: Identification of a GW compact binary merger candidate
  4. LIGO/Virgo S200308e: Retraction of GW compact binary merger candidate
  5. LIGO/Virgo S200302c: No notable candidates in GOTO imaging
  6. LIGO/Virgo S200302c : No significant candidates in FRAM - TAROT - GRANDMA observations.
  7. LIGO/Virgo S200225q: No notable candidates in GOTO imaging
  8. LIGO/Virgo S200302c: AstroSat CZTI upper limits
  9. LIGO/Virgo S200302c: Upper limits from Insight-HXMT/HE observations
  10. LIGO/Virgo S200303ba: Retraction of GW compact binary merger candidate
  11. LIGO/Virgo S200302c: No transient candidates in CALET observations
  12. LIGO/Virgo S200224ca: No counterpart candidates in TOROS observations
  13. LIGO/Virgo S200302c: Updated Sky Localization
  14. LIGO/Virgo S200302c: No significant counterpart candidates in Fermi-LAT observations
  15. LIGO/Virgo S200302c: No counterpart candidates in KAIT observations
  16. LIGO/Virgo S200302c: no counterpart candidates in the Swift/BAT observations
  17. LIGO/Virgo S200224ca: Transient found in Swift/UVOT counterpart search
  18. LIGO/Virgo S200302c: No counterpart candidates in HAWC observations
  19. LIGO/Virgo S200302c: Upper limits from Fermi-GBM Observations
  20. LIGO/Virgo S200302c: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  21. LIGO/Virgo S200302c : no neutrino counterpart candidate in ANTARES search
  22. LIGO/Virgo S200302c: upper limits from AGILE/MCAL observations
  23. LIGO/Virgo S200225q: AstroSat CZTI upper limits
  24. LIGO/Virgo S200219ac: AstroSat CZTI upper limits
  25. LIGO/Virgo S200302c: Coverage and upper limits from MAXI/GSC observations
  26. LIGO/Virgo S200302c: Upper limits from IceCube neutrino searches
  27. LIGO/Virgo S200302c: Identification of a GW compact binary merger candidate
  28. LIGO/Virgo S200302c: Global MASTER-Net observations report
  29. LIGO/Virgo S200225q : No significant candidates in TAROT - FRAM - GRANDMA observations.
  30. LIGO/Virgo S200224ca: Updated Sky Localization and EM Bright Classification
  31. LIGO/Virgo S200213t: No significant EM counterparts identified from continued GECKO observation of host galaxy candidates
  32. IceCube-200227A : Upper limits from Insight-HXMT/HE observations
  33. LIGO/Virgo S200224ca : No significant candidates in TAROT - FRAM - GRANDMA observations
  34. LIGO/Virgo S200225q: Not observable by CALET
  35. LIGO/Virgo S200224ca: Upper limits from CALET observations.
  36. LIGO/Virgo S200224car: GRAWITA VST-ESO PARANAL observations.
  37. LIGO/Virgo S200225q: Updated Sky Localization
  38. LIGO/Virgo S200224ca: DESGW Optical counterpart candidates from DECam
  39. LIGO/Virgo S200219ac: Upper limits from Konus-Wind observations
  40. LIGO/Virgo S200213t: Upper limits from Konus-Wind observations
  41. LIGO/Virgo S200208q: Upper limits from Konus-Wind observations
  42. LIGO/Virgo S200225q: no counterpart candidate in SVOM/GWAC observations
  43. LIGO/Virgo S200225q: Upper limits from Insight-HXMT/HE observations
  44. LIGO/Virgo S200224ca: Upper limits from Insight-HXMT/HE observations
  45. LIGO/Virgo S200225q: no counterpart candidates in the Swift/BAT observations
  46. LIGO/Virgo S200224ca: no counterpart candidates in the Swift/BAT observations
  47. LIGO/Virgo S200219ac: Updated Sky Localization
  48. LIGO/Virgo S200224ca: No counterpart candidates in KAIT observations
  49. LIGO/Virgo S200224ca: No Counterparts in DDOTI/OAN Optical Observations
  50. LIGO/Virgo S200224ca: GRAWITA-Campo Imperatore observations.
  51. LIGO/Virgo S200225q: Upper limits from Fermi-GBM Observations
  52. LIGO/Virgo S200225q: No counterpart candidates in Fermi-LAT observations
  53. LIGO/Virgo S200225q: upper limits from AGILE/GRID observations
  54. LIGO/Virgo S200224ca: Subaru/Hyper Suprime-Cam follow-up observations
  55. LIGO/Virgo S200225q: upper limits from AGILE/MCAL observations
  56. LIGO/Virgo S200225q: Upper limits from IceCube neutrino searches
  57. LIGO/Virgo S200225q: No counterpart candidates in HAWC observations
  58. LIGO/Virgo S200225q : no neutrino counterpart candidate in ANTARES search
  59. LIGO/Virgo S200225q: Global MASTER-Net observations report
  60. LIGO/Virgo S200224ca: No counterpart candidates in Fermi-LAT observations
  61. LIGO/Virgo S200225q: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  62. LIGO/Virgo S200225q: Coverage and upper limits from MAXI/GSC observations
  63. LIGO/Virgo S200219ac: No counterpart candidates from Nanshan/NEXT observations
  64. LIGO/Virgo S200224ca: upper limits from AGILE/GRID observations
  65. LIGO/Virgo S200225q: Identification of a GW compact binary merger candidate The LIGO Scientific Collaboration and the Virgo Collaboration
  66. LIGO/Virgo S200224ca: not observable by Fermi-GBM
  67. LIGO/Virgo S200224ca: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  68. LIGO/Virgo S200224ca: Coverage and upper limits from MAXI/GSC observations
  69. LIGO/Virgo S200224ca: upper limits from AGILE/MCAL observations
  70. LIGO/Virgo S200224ca: Global MASTER-Net observations report
  71. LIGO/Virgo S200224ca: Upper limits from IceCube neutrino searches
  72. LIGO/Virgo S200224ca: Identification of a GW compact binary merger candidate The LIGO Scientific Collaboration and the Virgo Collaboration
  73. GRB 200224A: Swift-XRT refined Analysis
  74. GRB 200224C: Fermi GBM Final Real-time Localization
  75. GRB 200224A: Tautenburg observations
  76. GRB 200224A: BOOTES-1 and 1.5m OSN optical observations
  77. Fermi trigger No 604213554: Global MASTER-Net observations report
  78. GRB 200224B: Fermi GBM Final Real-time Localization
  79. GRB 200224A: Swift detection of a burst
  80. Swift GRB200224.14: Global MASTER-Net observations report
  81. LIGO/Virgo S200219ac: no counterpart candidate in SVOM/GWAC-F30 observations
  82. LIGO/Virgo S200219ac: no counterpart candidate in SVOM/GWAC observations
  83. LIGO/Virgo S200219ac : No significant candidates in TAROT - FRAM - GRANDMA observations.
  84. IPN triangulation of GRB 200219B (inconsistent with the LIGO/Virgo S200219ac)
  85. LIGO/Virgo S200219ac: No counterpart candidates in KAIT observations
  86. LIGO/Virgo S200213t: AT2020clw/ZTF20aanaoyz, AT2020crd/ZTF20aanakge and AT2020cly/ZTF20aanakes 10.4m GTC spectroscopy
  87. LIGO/Virgo S200213t: Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)
  88. LIGO/Virgo S200219ac: No transient candidates in CALET observations
  89. LIGO/Virgo S200219ac: no counterpart candidates in the Swift/BAT observations
  90. LIGO/Virgo S200219ac: Fermi GBM transient event not confidently associated with GW signal
  91. LIGO/Virgo S200219ac: No counterpart candidates in Fermi-LAT observations
  92. LIGO/Virgo S200219ac: upper limits from AGILE/GRID observations
  93. LIGO/Virgo S200213t: Keck/LRIS spectroscopy of counterpart candidates from the Zwicky Transient Facility
  94. LIGO/Virgo S200219ac: upper limits from AGILE/MCAL observations
  95. LIGO/Virgo S200219ac : no neutrino counterpart candidate in ANTARES search
  96. LIGO/Virgo S200219ac: Upper limits from IceCube neutrino searches
  97. LIGO/Virgo S200219ac: No counterpart candidates in HAWC observations
  98. LIGO/Virgo S200219ac: Coverage and upper limits from MAXI/GSC observations
  99. LIGO/Virgo S200219ac: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  100. LIGO/Virgo S200219ac: Identification of a GW compact binary merger candidate

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