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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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

21109 results found.

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

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