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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').
Advanced Search

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"

21110 results found.

  1. GRB 191228A: UKIRT NIR upper limit
  2. LIGO/Virgo S191222n: No transient candidates in CALET observations
  3. Swift GRB191228.00: Global MASTER-Net observations report
  4. Swift GRB191227A: Global MASTER-Net OT detection
  5. Swift GRB191227.07: Global MASTER-Net observations report
  6. LIGO/Virgo S191213g: AT2019wxt 10.4m GTC further spectroscopy
  7. Swift GRB191226.25: Global MASTER-Net observations report
  8. Swift GRB191226.02: Global MASTER-Net observations report
  9. Swift trigger 946234/GRB 191226.02 : MASTER obervation
  10. LIGO/Virgo S191225aq: Global MASTER-Net observations report
  11. Fermi trigger No 598988276: Global MASTER-Net observations report
  12. GRB 191221B: ATCA detection of the radio afterglow
  13. LIGO/Virgo S191205ah: MASTER OT detection
  14. LIGO/Virgo S191213g: Pan-STARRS monitoring shows PS19hgw (AT2019wxt) to be fading quickly
  15. LIGO/Virgo S191222n : No significant candidates in FRAM-TAROT-GRANDMA observations
  16. GRB 191221B: Swift/UVOT Detection
  17. LIGO/Virgo S191222n: no counterpart candidate in SVOM/GWAC observations
  18. LIGO/Virgo S191216ap: Upper limits from Insight-HXMT/HE observations
  19. GRB 191221B: iTelescope optical observations
  20. GRB 191221B: ALMA detection
  21. LIGO/Virgo S191216ap: No significant candidates found in Pan-STARRS observations
  22. GRB 191221B: Zadko observatory - Gingin optical observations
  23. LIGO/Virgo S191213g : No significant candidates found in GRANDMA citizen science observations
  24. LIGO/Virgo S191222n: no counterpart candidates in the Swift/BAT observations
  25. LIGO/Virgo S191222n: No counterpart candidates in Fermi-LAT observations
  26. GRB 191221B: MASTER VWFC OT yearly detection
  27. GRB 191221B: Correction to GCN26551 - VIRT OT observation
  28. GRB 191221B: VIRT Optical Upper Limits
  29. GRB 191221B: AGILE/MCAL observations
  30. LIGO/Virgo S191222n: upper limits from AGILE-GRID observations
  31. LIGO/Virgo S191222n: upper limits from AGILE/MCAL observations
  32. LIGO/Virgo S191222n: Coverage and upper limits from MAXI/GSC observations
  33. LIGO/Virgo S191222n: INTEGRAL was inactive at the time of the event
  34. LIGO/Virgo S191222n: No counterpart candidates in HAWC observations
  35. LIGO/Virgo S191222n: Global MASTER-Net observations report
  36. Baksan Neutrino Observatory Alert 191222.09: Global MASTER-Net observations report
  37. GRB 191221B: MASTER OT detection
  38. Swift GRB 191221B: Global MASTER-Net observations report
  39. Fermi trigger No 598648473: Global MASTER-Net observations report
  40. LIGO/Virgo S191216ap: VLA/JAGWAR radio monitoring of the 1-sigma HAWC region
  41. LIGO/Virgo S191216ap: No radio candidates so far in the VLA/JAGWAR galaxy targeted search
  42. LIGO/Virgo S191216ap: MASTER optical observation
  43. LIGO/Virgo S191216ap : No significant candidates in FRAM-TAROT-GRANDMA observations
  44. LIGO/Virgo S191213g: VLA follow-up of AT2019wxt/PS19hg
  45. GRB 191220A: Swift/UVOT Upper Limits
  46. GRB 191220A: AbAO optical observations
  47. Fermi trigger No 598543714: Global MASTER-Net observations report
  48. LIGO/Virgo S191213g: AT2019wxt 10.4m GTC spectroscopy
  49. LIGO/Virgo S191213g : SAO 1-m optical observation of AT2019wxt (PS19hgw)
  50. GRB 191220A: SAO RAS possible OT detection
  51. LIGO/Virgo S191213g: DCT observation of AT2019wxt
  52. Swift GRB191220.56: Global MASTER-Net observations report
  53. LIGO/Virgo S191220af: Global MASTER-Net observations report
  54. LIGO/Virgo S191213g: YAHPT Observations of AT2019wxt(PS19hgw)
  55. LIGO/Virgo S191216ap: Subaru/Hyper Suprime-Cam observations of GW+IceCube+HAWC error region
  56. LIGO/Virgo S191213g: LBT spectrum of AT2019wxt (PS19hgw) reveals a type IIb supernova
  57. LIGO/Virgo S191213g: VLT spectrum of AT2019wxt (PS19hgw) - a probable Ib supernova
  58. LIGO/Virgo S191213g: Lulin Follow-up Observations of AT2019wxt
  59. LIGO/Virgo S191213g: Swift UVOT/XRT observations of Pan-STARRS1 candidate: PS19hgw
  60. LIGO/Virgo S191213g: GRAWITA TNG NIR imaging of AT2019wxt (PS19hgw)
  61. LIGO/Virgo S191216ap, Swift XRT observations: 16 X-ray sources in the HAWC error region search
  62. LIGO/Virgo S191216ap: No candidates found in J-GEM follow-up observations of HAWC error region
  63. LIGO/VIRGO S191213g: ePESSTO+ spectroscopy of AT2019wxt (PS19hgw)
  64. LIGO/VIRGO S191213g: LT spectroscopy of AT2019wxt (PS19hgw)
  65. LIGO/Virgo S191213g: HCT spectroscopy of PS19hgw / AT2019wxt
  66. LIGO/Virgo S191216ap: Correction to GCN 26488 (NOWT observations)
  67. LIGO/Virgo S191213g: No counterpart candidate in the NOWT observations
  68. LIGO/Virgo S191216ap: No candidates found in CHES observations of HAWC error region
  69. LIGO/Virgo S191216ap and IceCube neutrino: no counterpart candidates from AGILE-GRID observations
  70. LIGO/Virgo S191216ap: GRAWITA Loiano observations of HAWC error region
  71. LIGO/Virgo S191216ap: No transient candidates in CALET observations
  72. LIGO/Virgo S191216ap: Nanshan follow-up observations
  73. LIGO/Virgo S191213g: No candidates found in J-GEM follow-up observations
  74. LIGO/Virgo S191216ap: galaxies consistent with GW + Neutrino + HAWC position
  75. LIGO/Virgo S191216ap and IceCube neutrino: Swift XRT sources
  76. LIGO/Virgo S191216ap: IceCube event: MASTER OF detection in GW and Neutrino error field
  77. LIGO/Virgo S191216ap: No significant counterpart candidates in SAGUARO observations
  78. LIGO/Virgo S191216ap: HAWC gamma-ray sub-threshold event coincident with LIGO/Virgo and IceCube localizations
  79. LIGO/Virgo S191213g: Swift UVOT/XRT observations of three ZTF sources
  80. LIGO/Virgo S191215w : No significant candidates in TAROT - FRAM - GRANDMA observations.
  81. LIGO/Virgo G191216ap: No counterpart candidates in Fermi-LAT observations
  82. LIGO/Virgo S191213g: MASTER OT detection in BNS error-box
  83. LIGO/Virgo S191216ap: no counterpart candidates in the Swift/BAT observations
  84. LIGO/Virgo S191215w: No transient candidates in CALET observations
  85. LIGO/Virgo S191216ap: No Candidates from the Zwicky Transient Facility
  86. LIGO/Virgo S191216ap: Coverage and upper limits from MAXI/GSC observations
  87. LIGO/Virgo S191216ap: Upper limits from Fermi-GBM Observations
  88. Fermi-LAT Gamma-ray Observations of IceCube-191215A
  89. LIGO/Virgo S191216ap: Global MASTER-Net observations report
  90. LIGO/Virgo S191216ap: No counterpart candidates in HAWC observations
  91. LIGO/Virgo S191215w: no counterpart candidates in the Swift/BAT observations
  92. LIGO/Virgo S191215w: No counterpart candidates in Fermi-LAT observations
  93. UKIRT photometry of ZTF19acyldun/AT 2019wrt
  94. LIGO/Virgo S191215w: upper limits from AGILE-GRID observations
  95. LIGO/Virgo S191215w: upper limits from AGILE/MCAL observations
  96. LIGO/Virgo S191215w: Upper limits from Fermi-GBM Observations
  97. LIGO/Virgo S191215w: No counterpart candidates in HAWC observations
  98. LIGO/Virgo S191215w: Coverage and upper limits from MAXI/GSC observations
  99. LIGO/Virgo S191215w: Global MASTER-Net observations report
  100. IceCube-191215A: not observable by Fermi-GBM

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