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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"

19548 results found.

  1. LIGO/Virgo S190814bv: No radio counterpart to DG19wxnjc/AT2019npv in ASKAP observations
  2. GRB 190824A: Enhanced Swift-XRT position
  3. Fermi GBM-190816: Updated localization of subthreshold GRB-GW candidate
  4. GRB 190824A: Swift detection of a burst
  5. GRB 190823A: Tiled Swift observations
  6. LIGO/Virgo S190814bv: GROND follow-up observations of AT2019npv
  7. GRB 190821A: Swift/UVOT Upper Limits
  8. LIGO/Virgo S190814bv: NIR imaging follow-up of ASKAP transient
  9. GRB 190821A: MASTER VWFC syncronous optical observations
  10. LIGO/Virgo S190814bv: ENGRAVE VLT/HAWK-I observations and archival detection of the CFHT candidate
  11. LIGO/Virgo S190814bv: No radio counterpart detected in ASKAP observations
  12. GRB 190821A: Enhanced Swift-XRT position
  13. Fermi GBM-190816: Upper Limits from Swift/BAT Observations
  14. GRB 190821A: T60 Les Makes optical detection of the afterglow
  15. Swift GRB190821.72 Global MASTER-Net observations report
  16. GRB 190821A: Swift detection of a burst
  17. Fermi GBM-190816: No counterpart candidates in Fermi-LAT observations
  18. Fermi-LAT Gamma-ray Observations of IceCube-190819A
  19. LIGO/Virgo S190814bv: RATIR Optical observations of DECam transients
  20. LIGO/Virgo GBM-190816: no counterpart candidates in the Swift/BAT Observations
  21. IceCube-190819A - HAWC follow-up
  22. Fermi GBM-190816: No counterpart candidates in HAWC observations
  23. LIGO/Virgo S190814bv: No neutrino candidates at Pierre Auger Observatory
  24. Fermi GBM-190816+LIGO/Virgo : no neutrino counterpart candidate in ANTARES search
  25. Fermi GBM-190816: Location-dependent upper limits from INTEGRAL/SPI-ACS prompt observation
  26. Fermi GBM-190816: A subthreshold GRB candidate potentially associated with a subthreshold LIGO/Virgo compact binary merger candidate
  27. IceCube-190819A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  28. LIGO/Virgo S190814bv: No candidates from image subtraction in DCT galaxy targeted search
  29. LIGO/Virgo S190814bv: WIRC NIR imaging follow-up of DECam transients
  30. LIGO/VIRGO S190814bv: AbAO non-detection of AT2019nme
  31. LIGO/Virgo S190814bv: No candidates found in J-GEM follow-up observations
  32. LIGO/Virgo S190814bv: Fermi-LAT search for a high-energy gamma-ray counterpart
  33. LIGO/Virgo S190814bv : No Counterpart Candidates in Continued Galaxy Targeted Search with Magellan
  34. LIGO/Virgo S190814bv: No candidates found in J-GEM follow-up observations
  35. LIGO/VIRGO S190814bv: No candidates from ATLAS observations
  36. LIGO/Virgo S190814bv: No candidates from DCT galaxy targeted search and observations of DECam-GROWTH candidates
  37. LIGO/Virgo S190814bv: GROND imaging of candidate galaxies
  38. SUBJECT: LIGO/Virgo S190814bv: GRAWITA VST-ESO PARANAL observations
  39. LIGO/Virgo S190814bv : No Counterpart Candidates in Galaxy Targeted Search with Magellan
  40. LIGO/Virgo S190814bv: No Candidates Found in Wide-Field Infrared Search with Palomar Gattini-IR
  41. LIGO/Virgo S190814bv: No Counterparts in DDOTI/OAN Optical Observations
  42. LIGO/Virgo S190814bv: no counterpart candidates in Thacher imaging
  43. LIGO/Virgo S190814bv: no counterpart candidates in Swope imaging
  44. LIGO/Virgo S190814bv: no counterpart candidates in Nickel/Direct imaging and non-detections of 2019nmd and 2019nme
  45. LIGO/Virgo S190814bv: ATLAS forced photometry non-detections of DESGW candidates
  46. Non-detection of DESGW-190814a in ZTF forced photometry
  47. LIGO/Virgo S190814bv: no counterpart candidates in Keck I MOSFIRE imaging
  48. LIGO/Virgo S190814bv: KMTNet observation
  49. LIGO/Virgo S190814bv: No counterpart candidates in the Swift/BAT Observations
  50. LIGO/Virgo S190814bv: MeerLICHT coverage second preliminary skymap
  51. LIGO/Virgo S190814bv: no candidates from GOTO imaging observations
  52. LIGO/Virgo S190814bv : no neutrino counterpart candidate in ANTARES search
  53. LIGO/Virgo S190814bv: Upper limits from Fermi-GBM Observations
  54. LIGO/Virgo S190814bv: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  55. IPN triangulation of GRB 190810A (short)
  56. HAWC-190806A: upper limits from INTEGRAL SPI-ACS and IBIS prompt observation
  57. Trigger_11505: Tiled Swift observations
  58. LIGO/Virgo S190808ae: Coverage and upper limits from MAXI/GSC observations
  59. LIGO/Virgo S190808ae: No counterpart candidates in HAWC observations
  60. GRB 190808B: Fermi GBM Final Real-time Localization
  61. GRB 190808A: Fermi GBM Final Real-time Localization
  62. GRB 190804B: Swift-XRT afterglow detection
  63. Alert from the HAWC Burst Monitor
  64. GRB 190805B: Swift-XRT observations
  65. GRB 190805B: Tiled Swift observations
  66. GRB 190804B: Tiled Swift observations
  67. GRB 190731A: Swift/UVOT Upper Limits
  68. GRB 190731A: no OT detected by MASTER
  69. IceCube 190730A: No counterpart candidates or blazar activity in GOTO observations
  70. GRB 190731A: Swift-XRT afterglow detection
  71. IPN Triangulation of GRB 190731A
  72. GRB 190731A: Swift ToO observations
  73. Fermi-LAT Gamma-ray Observations of IceCube-190730A
  74. IceCube-190730A - HAWC follow-up
  75. IceCube 190730A: one weakly associated counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
  76. LIGO/Virgo S190707q: AstroSat CZTI upper limits
  77. LIGO/Virgo S190728q: GRAWITA VST-ESO PARANAL observations
  78. LIGO/Virgo S190728q/IceCube neutrino candidate: No counterpart candidates in the Swift-XRT Observations
  79. S190728q: MASTER multiple previous outbursts detection of ZTF19abjethn=AT2019lvs
  80. LIGO/Virgo S190728q: No counterpart candidates in the Swift/BAT Observations
  81. LIGO/Virgo S190728q: Optical Candidate from the Zwicky Transient Facility ZTF19abjethn
  82. LIGO/Virgo S190728q: No counterpart candidates in Fermi-LAT observations
  83. LIGO/Virgo S190728q : no neutrino counterpart candidate in ANTARES search
  84. LIGO/Virgo S190728q: No counterpart candidates in HAWC observations
  85. LIGO/Virgo S190728q: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  86. LIGO/Virgo S190727h: No counterpart candidates in the Swift/BAT Observations
  87. LIGO/Virgo S190727h: No counterpart candidates in Fermi-LAT observations
  88. LIGO/Virgo S190727h: possible counterpart candidate in SPI-ACS/INTEGRAL
  89. LIGO/Virgo S190727h: No counterpart candidates in HAWC observations
  90. LIGO/Virgo S190727h : no neutrino counterpart candidate in ANTARES search
  91. LIGO/Virgo S190727h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  92. LIGO/Virgo S190727h: Coverage and upper limits from MAXI/GSC observations
  93. LIGO/Virgo S190727h: Identification of a GW compact binary merger candidate
  94. LIGO/Virgo S190720a: Thacher Observatory follow-up observations
  95. GRB 190719C: optical afterglow confirmation
  96. LIGO/Virgo S190720a: No counterpart candidates in CNEOST observations
  97. LIGO/Virgo S190720a: No counterpart candidates in Fermi-LAT observations
  98. GRB 190719C: Swift/UVOT Upper Limits
  99. LIGO/Virgo S190720a: No counterpart candidates in the Swift/BAT Observations
  100. LIGO/Virgo S190720a: Upper limits from Fermi-GBM Observations

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