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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"

16286 results found.

  1. GRB 200205A: REM optical observations
  2. GRB 200205A: MASTER Ot detection
  3. GRB 200131A: Further RATIR Optical Observations
  4. AMON IceCube-HAWC_200202A: MASTER optical inspect
  5. ZTF20aajnksq: Gemini-North r-band photometry
  6. ZTF Discovery of ZTF20aajnksq: a Rapidly Fading Luminous Transient in the GRB 200128A Localiziation Region
  7. GRB 200131A: ISON-Castelgrande optical observations
  8. GRB 200131A: CDK700 optical observations
  9. GRB 200131A: VIRT optical transient detection
  10. GRB 200131A: LCO Optical Detection
  11. GRB 200131A: KAIT Optical Upper Limit
  12. GRB 200131A: RATIR Optical Observations
  13. GRB 200131A: MASTER optical transient detection
  14. GRB 200131A: Swift detection of a burst with an optical counterpart
  15. Fermi-LAT ANTARES 200127.79 coincidence: MASTER alert observation and presence of young pulsar close to error-box
  16. GRB 200127A: Swift/UVOT Upper Limits
  17. GRB 200127A: Mondy optical upper limit
  18. GRB200127A: Nordic Optical telecope optical upper limit
  19. GRB 200125B: DDOTI/OAN optical observations report
  20. GRB 200127A: Nanshan-0.6m optical upper limit
  21. GRB 200127A: AbAO optical upper limit
  22. GRB 200125A: Swift/UVOT Upper Limits
  23. GRB 200125A: Further RATIR Optical Observations and Confirmation of Fading
  24. GRB 200125A: AbAO optical upper limit
  25. GRB 200125A: TNG detection of a NIR counterpart candidate
  26. GRB 200125A: Nanshan-0.6m optical upper limit
  27. GRB 200125A: RATIR Optical Observations
  28. GRB 200122A: Optical upper limit: correction to the GCN circ. 26870
  29. GRB 200115A: Assy optical observations
  30. GRB 200122A: Optical upper limit
  31. GRB 200122A: Mondy optical upper limit
  32. GRB 200122A: MITSuME Akeno optical upper limits
  33. LIGO/Virgo S200115j: Zwicky Transient Facility search for optical counterparts to Swift X-ray sources
  34. GRB 200122A: RATIR Optical Observations
  35. GRB 200122A: Xinglong-2.16m optical upper limit
  36. GRB 200122A: Swift/UVOT Upper Limits
  37. LIGO/Virgo S200115j: Further Swift-XRT sources
  38. GRB 200122A: FRAM-ORM optical limit
  39. GRB 200122A: GOTO non-detection of optical afterglow
  40. LIGO/Virgo S200114f: SOAR spectroscopy of AT2020zf, AT2020ace and AT2020ach
  41. LIGO/Virgo S200115j: No counterpart detection within possible host galaxies observed by the GRAWITA-Savelli telescope
  42. GRB 200115A: Mondy optical observations and correction to GCN 26790
  43. LIGO/Virgo S200114f: More candidates from the Zwicky Transient Facility
  44. GRB 200115A: AROMA-N Optical Observation
  45. LIGO/Virgo S200115j: No notable candidates in GOTO imaging
  46. GRB 200115A: DDOTI/OAN optical observations report
  47. GRB 200115A: Mondy optical afterglow candidate
  48. GRB 200115A: Swift-BAT refined analysis
  49. GRB 200115A: MITSuME Okayama optical upper limits
  50. GRB 200115A: Nanshan-0.6m optical upper limit
  51. LIGO/Virgo S200114f: AT2020vr, AT2020vt, AT2020wa and AT2020wc 10.4m GTC spectroscopy
  52. GRB 200114A: DDOTI/OAN optical observations report
  53. LIGO/Virgo S200114f: No Counterparts in DDOTI/OAN Optical Observations
  54. LIGO/Virgo S200114f: Constraints on a CCSN origin from KM3NeT MeV neutrino search.
  55. LIGO/Virgo S200105ae: AT2020pq, AT2020ps and AT2020pv 10.4m GTC spectroscopy
  56. LIGO/Virgo S200105ae: AT2020pp and AT2020py 10.4m GTC spectroscopy
  57. LIGO/Virgo S200105ae: AT2020oo 10.4m GTC spectroscopy
  58. GRB 200107B: Swift/UVOT Observations
  59. GRB 200109A: Swift/UVOT Upper Limits
  60. Fermi-LAT ANTARES coincidence /ANTARES alert 200108.39: MASTER alert and inspect observation
  61. LIGO/Virgo S200105ae: Candidates from the Zwicky Transient Facility
  62. Swift GRB200107.81: Global MASTER-Net OT detection
  63. GRB 191228A: FRAM-ORM optical limit
  64. GRB 191228A: Early Optical Upper Limits from LCO
  65. GRB 191228A: Mondy optical upper limit
  66. GRB 191228A: Swift/UVOT Upper Limits
  67. GRB 191228A: ePESSTO+ NTT optical upper limit
  68. GRB 191227A: MITSuME Akeno optical upper limits
  69. Swift GRB191227A: Global MASTER-Net OT detection
  70. LIGO/Virgo S191213g: AT2019wxt 10.4m GTC further spectroscopy
  71. Swift trigger 946234/GRB 191226.02 : MASTER obervation
  72. GRB 191221B: ATCA detection of the radio afterglow
  73. LIGO/Virgo S191213g: Pan-STARRS monitoring shows PS19hgw (AT2019wxt) to be fading quickly
  74. GRB 191221B: iTelescope T17 detection
  75. GRB 191221B: iTelescope optical observations
  76. GRB 191221B: ALMA detection
  77. LIGO/Virgo S191216ap: No significant candidates found in Pan-STARRS observations
  78. GRB 191221B: Zadko observatory - Gingin optical observations
  79. GRB 191221B: LCO Optical Detection
  80. GRB 191221B: MASTER VWFC OT yearly detection
  81. GRB 191221B: VLT/X-shooter redshift
  82. GRB 191221B: VIRT Optical Upper Limits
  83. GRB 191221B: MASTER OT detection
  84. GRB 191221B: Swift detection of a burst and a very bright optical candidate
  85. LIGO/Virgo S191216ap: MASTER optical observation
  86. LIGO/Virgo S191213g: VLA follow-up of AT2019wxt/PS19hg
  87. GRB 191220A: Swift/UVOT Upper Limits
  88. GRB 191220A: AbAO optical observations
  89. LIGO/Virgo S191213g: AT2019wxt 10.4m GTC spectroscopy
  90. LIGO/Virgo S191213g : SAO 1-m optical observation of AT2019wxt (PS19hgw)
  91. LIGO/Virgo S191213g: LBT spectrum of AT2019wxt (PS19hgw) reveals a type IIb supernova
  92. LIGO/Virgo S191213g: VLT spectrum of AT2019wxt (PS19hgw) - a probable Ib supernova
  93. LIGO/Virgo S191205ah: AT2019wmy 10.4m GTC spectroscopy
  94. LIGO/Virgo S191213g: MASTER observation of AT2019wxt (PS19hgw)
  95. LIGO/Virgo S191216ap: No candidates found in J-GEM follow-up observations of HAWC error region
  96. LIGO/VIRGO S191213g: LT spectroscopy of AT2019wxt (PS19hgw)
  97. LIGO/Virgo S191213g: AT2019wnh, AT2019wnk and AT2019wrt 10.4m GTC spectroscopy
  98. LIGO/Virgo S191213g: NOT optical spectroscopy of AT2019wxt (PS19hgw)
  99. LIGO/Virgo S191213g: No counterpart candidate in the NOWT observations
  100. LIGO/Virgo S191213g: Pan-STARRS1 discovery of a potential optical counterpart

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