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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"
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submitter:"Judith Racusin"

11851 results found.

  1. LIGO/Virgo S190930t: Candidates from ATLAS observations and constraints on AT2019rpr and AT2019rpn
  2. GRB 191001A: RATIR Optical and NIR Observations
  3. LIGO/Virgo S190930t: Lulin Follow-up Observations of AT2019rpn and AT2019rpj
  4. IceCube-191001A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  5. IceCube-191001A - IceCube observation of a high-energy neutrino candidate event
  6. LIGO/Virgo S190930s: No counterpart candidates in KAIT observations
  7. GRB 191001A: DDOTI Optical Counterpart Candidate
  8. IceCube Alert 191001.84: Global MASTER-Net observations report
  9. LIGO/Virgo S190814bv: VLA 6 GHz observations of 75 galaxies in the 90% localization region
  10. GRB 191001B: Swift detection of a burst
  11. LIGO/Virgo S190930t: No counterpart candidates in Fermi-LAT observations
  12. LIGO/Virgo S190930s: No counterpart candidates in Fermi-LAT 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 S190930t: No counterpart candidates in HAWC observations
  16. LIGO/Virgo S190930s: Coverage and upper limits from MAXI/GSC observations
  17. Fermi trigger No 591532362: Global MASTER-Net observations report
  18. Konus-Wind observation of GRB 190928A
  19. Fermi trigger No 591391412: Global MASTER-Net observations report
  20. GRB 190928A: AGILE/MCAL detection of a burst
  21. GRB 190926A: Swift-XRT refined Analysis
  22. LIGO/Virgo S190923y: No significant candidates in TAROT-GRANDMA observations
  23. LIGO/Virgo S190924h: No counterpart candidates in Fermi-LAT observations
  24. Fermi-LAT Gamma-ray Observations of IceCube-190922B
  25. LIGO/Virgo S190924h: Coverage and upper limits from MAXI/GSC observations
  26. LIGO/Virgo S190923y: No counterpart candidates in Fermi-LAT observations
  27. Fermi-LAT Gamma-ray Observations of IceCube-190922A
  28. LIGO/Virgo S190923y: Coverage and upper limits from MAXI/GSC observations
  29. LIGO/Virgo S190923y: No counterpart candidates in HAWC observations
  30. IceCube Alert 190922.96: Global MASTER-Net observations report
  31. IceCube-190922A - IceCube observation of a high-energy neutrino candidate event
  32. Baksan Neutrino Observatory Alert 190920.65: Global MASTER-Net observations report
  33. GRB 190919B: LCO Optical Afterglow Detection
  34. GRB 190919B: FRAM-Auger optical detection
  35. GRB 190919B: Swift-XRT observations
  36. GRB 190919B: A long GRB detected by INTEGRAL
  37. Integral GRB190919.99: Global MASTER-Net observations report
  38. Fermi trigger No 590621700: Global MASTER-Net observations report
  39. GRB 190919A: Fermi GBM Final Real-time Localization
  40. LIGO/Virgo S190915ak: No significant candidates in TAROT-GRANDMA observations
  41. LIGO/Virgo S190910h: No significant candidates in TAROT-GRANDMA observations
  42. LIGO/Virgo S190915ak: No counterpart candidates in Fermi-LAT observations
  43. LIGO/Virgo S190915ak: Coverage and upper limits from MAXI/GSC observations
  44. LIGO/Virgo S190915ak: Global MASTER-Net observations report
  45. LIGO/Virgo S190910d : No significant candidates in TAROT-GRANDMA observations
  46. Fermi trigger No 590038994: Global MASTER-Net observations report
  47. LIGO/Virgo S190910h: No counterpart candidates in Fermi-LAT observations
  48. LIGO/Virgo S190910h: Gaia Photometric Alerts transient candidates
  49. LIGO/Virgo S190910d and S190910h: No counterpart candidates in KAIT observations
  50. LIGO/Virgo S190910d: AT2019pvu, AT2019pvv, AT2019pvz and AT2019pwa 10.4m GTC spectroscopy
  51. LIGO/Virgo S190910d: Liverpool Telescope spectroscopy of ZTF19abyfazm
  52. LIGO/Virgo S190910d: AstroSat CZTI upper limits
  53. LIGO/Virgo S190910d: No counterpart candidates in Fermi-LAT observations
  54. LIGO/Virgo S190910h: No counterpart candidates in HAWC observations
  55. LIGO/Virgo S190910h Global MASTER-Net observations report
  56. LIGO/Virgo S190910h: Coverage and upper limits from MAXI/GSC observations
  57. LIGO/Virgo S190910d: Coverage and upper limits from MAXI/GSC observations
  58. LIGO/Virgo S190910d: No counterpart candidates in HAWC observations
  59. LIGO/Virgo S190901ap : No significant candidates found in GRANDMA citizen science observations
  60. ZTF19abvizsw: AbAO and CrAO photometry
  61. LIGO/Virgo S190814bv: GRAWITA VST-ESO PARANAL observations and independent transient candidates discovery.
  62. LIGO/Virgo S190901ap : No significant candidates in TAROT-GRANDMA
  63. LIGO/Virgo S190901ap: No counterpart candidates in KAIT observations
  64. Konus-Wind observation of GRB 190829A
  65. Swift XRT Detection of X-ray Emission from ZTF19abvizsw
  66. LIGO/Virgo S190901ap: GOTO optical coverage and detection of AT2019pjv
  67. LIGO/Virgo S190901ap: GTC follow-up spectroscopic observations of ZTF19abvizsw
  68. LIGO/Virgo S190901ap : GRAWITA photometric observation of candidate ZTFabvizsw and GCN 25618 revision
  69. LIGO/Virgo S190901ap: no counterpart candidate in the SVOM/GWAC observations
  70. Liverpool Telescope observations of ZTF19abvizsw, a candidate untriggered GRB afterglow
  71. LIGO/Virgo S190901ap: Upper limits from AGILE-GRID observations
  72. LIGO/Virgo S190828l: no counterpart candidate in the SVOM/GWAC observations
  73. LIGO/Virgo S190828j: no counterpart candidate in the SVOM/GWAC observations
  74. LIGO/Virgo S190901ap: No counterpart candidates in Fermi-LAT observations
  75. LIGO/Virgo S190901ap: Coverage and upper limits from MAXI/GSC observations
  76. LIGO/Virgo S190901ap: No counterpart candidates in HAWC observations
  77. Fermi trigger No 589060361 Global MASTER-Net observations report
  78. GRB 190829A: Keck LRIS spectroscopy of the optical afterglow
  79. LIGO/Virgo S190828j : No significant candidates in TAROT-GRANDMA observations
  80. LIGO/Virgo S190828l: No significant candidates in TAROT-GRANDMA observations
  81. GRB 190829A: Follow up VLA and VLBI radio observations urged
  82. GRB 190829A, Swift-BAT refined analysis
  83. GRB 190829A: Fermi GBM detection
  84. GRB 190829A: Fermi-LAT Upper Limits
  85. GRB 190829A:: Global MASTER-net optical clear and polarization observations scheduler and some spiculations
  86. GRB 190829A: Swift-XRT refined Analysis
  87. GRB 190830B: Fermi GBM Final Real-time Localization
  88. LIGO/Virgo S190828l: No counterpart candidates in KAIT observations
  89. GRB 190829A:: MASTER-net bright and decay OT detection
  90. GRB 190829A: Dabancheng-0.5m optical afterglow detection
  91. Fermi trigger No 588801358 Global MASTER-Net observations report
  92. GRB 190828B: Swift-XRT refined Analysis
  93. LIGO/Virgo S190814bv: VLA observation of ASKAP J005547-270433/AT2019osy
  94. LIGO/Virgo S190828l: No counterpart candidates in Fermi-LAT observations
  95. LIGO/Virgo S190828j: No counterpart candidates in KAIT observations
  96. LIGO/Virgo S190828j: No counterpart candidates in Fermi-LAT observations
  97. GRB 190828D: A long GRB detected by INTEGRAL
  98. Integral GRB190828.78 Global MASTER-Net observations report
  99. GRB 190828B: Swift detection of a burst
  100. LIGO/Virgo S190828l: Coverage and upper limits from MAXI/GSC observations

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