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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"

21112 results found.

  1. GRB 200205B: ESO/NTT near-infrared imaging
  2. GRB 200205A = Swift J0840.7-3516, A newly discovered transient X-ray Pulsar
  3. Fermi trigger No 602626648: Global MASTER-Net observations report
  4. Swift GRB200205.81: Global MASTER-Net observations report
  5. GRB 200205A / Swift trigger 954304: VLT optical observations
  6. GRB 200205A: REM optical observations
  7. MAXI GRB200205.29: Global MASTER-Net observations report
  8. GRB 200205A: MASTER Ot detection
  9. Swift GRB 200205A: Global MASTER-Net observations report
  10. Fermi trigger No 602455182: Global MASTER-Net observations report
  11. LIGO/Virgo S200129m: Upper limits from Konus-Wind observations
  12. LIGO/Virgo S200128d: Upper limits from Konus-Wind observations
  13. GRB 200131A: Further RATIR Optical Observations
  14. GRB200120A: SRG/ART-XC Upper Limit
  15. AMON IceCube-HAWC_200202A: MASTER optical inspect
  16. Fermi trigger No 602392636: Global MASTER-Net observations report
  17. ZTF20aajnksq: Gemini-North r-band photometry
  18. ZTF Discovery of ZTF20aajnksq: a Rapidly Fading Luminous Transient in the GRB 200128A Localiziation Region
  19. GRB 200131A: ISON-Castelgrande optical observations
  20. GRB 200131A: CDK700 optical observations
  21. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-200202A
  22. GRB 200131A: Swift/UVOT Detection
  23. GRB 200131A: VIRT optical transient detection
  24. GRB 200131A: KAIT Optical Upper Limit
  25. GRB 200131A: RATIR Optical Observations
  26. GRB 200131A: MASTER optical transient detection
  27. Swift GRB200131.95: Global MASTER-Net observations report
  28. Konus-Wind observation of GRB 200125B
  29. LIGO/Virgo S200128d: no counterpart candidate in SVOM/GWAC observations
  30. LIGO/Virgo S200128d : No significant candidates in FRAM - TAROT - GRANDMA observations
  31. Fermi trigger No 602071201: Global MASTER-Net observations report
  32. Fermi trigger No 602056641: Global MASTER-Net observations report
  33. LIGO/Virgo S200129m: Upper limits from CALET observations.
  34. LIGO/Virgo S200129m: no counterpart candidates in the Swift/BAT observations
  35. LIGO/Virgo S200129m: NED Galaxies in the 50% Localization Volume
  36. LIGO/Virgo S200129m: No counterpart candidates in Fermi-LAT observations
  37. LIGO/Virgo S200129m: Not observable by Fermi-GBM
  38. LIGO/Virgo S200128d: upper limits from AGILE/GRID observations
  39. LIGO/Virgo S200129m: Global MASTER-Net observations report
  40. LIGO/Virgo S200129m: upper limits from AGILE/GRID observations
  41. LIGO/Virgo S200129m: upper limits from AGILE/MCAL observations
  42. LIGO/Virgo S200129m: Coverage and upper limits from MAXI/GSC observations
  43. LIGO/Virgo S200128d: No counterpart candidates in Fermi-LAT observations
  44. LIGO/Virgo S200128d: Upper limits from CALET observations
  45. LIGO/Virgo S200128d: No counterpart candidates in KAIT observations
  46. LIGO/Virgo S200128d: no counterpart candidates in the Swift/BAT observations
  47. Fermi-LAT ANTARES 200127.79 coincidence: MASTER alert observation and presence of young pulsar close to error-box
  48. GRB 200127A: Swift/UVOT Upper Limits
  49. LIGO/Virgo S200128d: Upper limits from Fermi-GBM Observations
  50. GRB 200125B: DDOTI/OAN optical observations report
  51. LIGO/Virgo S200128d: Coverage and upper limits from MAXI/GSC observations
  52. LIGO/Virgo S200128d: No counterpart candidates in HAWC observations
  53. GRB 200127A: Nanshan-0.6m optical upper limit
  54. LIGO/Virgo S200128d: Global MASTER-Net observations report
  55. Fermi trigger No 601841483: Global MASTER-Net observations report
  56. Swift GRB200127.61: Global MASTER-Net observations report
  57. GRB 200125A: Further Swift-XRT observations
  58. GRB 200125B: Fermi GBM observations
  59. GRB 200125A: Swift/UVOT Upper Limits
  60. GRB 200125A: Further RATIR Optical Observations and Confirmation of Fading
  61. Fermi trigger No 601729856: Global MASTER-Net observations report
  62. Fermi trigger No 601677816: Global MASTER-Net observations report
  63. GRB 200125A: Nanshan-0.6m optical upper limit
  64. GRB 200125A: RATIR Optical Observations
  65. Swift GRB 200125A: Global MASTER-Net observations report
  66. LIGO/Virgo S200114f : No significant candidates in TAROT - FRAM - GRANDMA observations
  67. IceCube-200120A: Event likely due to background
  68. GRB 200115A: Assy optical observations
  69. GRB 200122A: RATIR Optical Observations
  70. GRB 200122A: Xinglong-2.16m optical upper limit
  71. GRB 200122A: Swift/UVOT Upper Limits
  72. Fermi trigger No 601363105: Global MASTER-Net observations report
  73. LIGO/Virgo S200115j: Further Swift-XRT sources
  74. GRB 200122A: GOTO non-detection of optical afterglow
  75. Fermi-LAT Gamma-ray Observations of IceCube-200120A
  76. LIGO/Virgo S200115j: Upper limits from Konus-Wind observations
  77. LIGO/Virgo S200114f: Upper limits from Konus-Wind observations
  78. LIGO/Virgo S200112r: Upper limits from Konus-Wind observations
  79. Swift GRB 200122A: Global MASTER-Net observations report
  80. Fermi trigger No 601254300: Global MASTER-Net observations report
  81. GRB 191031D: XMM-Newton upper limit
  82. LIGO/VIRGO S200115j: No obvious candidates from Pan-STARRS2 observations
  83. LIGO/Virgo S200105ae: Upper limits from Konus-Wind observations
  84. LIGO/Virgo S191222n: Upper limits from Konus-Wind observations
  85. LIGO/Virgo S191216ap: Upper limits from Konus-Wind observations
  86. LIGO/Virgo S191215w: Upper limits from Konus-Wind observations
  87. IceCube-200120A: not observable by Fermi-GBM
  88. LIGO/Virgo S200114f: SOAR spectroscopy of AT2020zf, AT2020ace and AT2020ach
  89. IceCube Alert 200120.78: Global MASTER-Net observations report
  90. LIGO/Virgo S191213g: Upper limits from Konus-Wind observations
  91. LIGO/Virgo S191205ah: Upper limits from Konus-Wind observations
  92. LIGO/Virgo S191204r: Upper limits from Konus-Wind observations
  93. LIGO/Virgo S191129u: Upper limits from Konus-Wind observations
  94. LIGO/Virgo S200115j: No counterpart detection within possible host galaxies observed by the GRAWITA-Savelli telescope
  95. Fermi-LAT Gamma-ray Observations of IceCube-200117A
  96. LIGO/Virgo S200115j : No significant candidates in TAROT - FRAM - GRANDMA observations
  97. GRB 200115A: Mondy optical observations and correction to GCN 26790
  98. IceCube-200117A: One Additional Candidate Counterpart from the Zwicky Transient Facility
  99. IceCube-200117A : Upper limits from Insight-HXMT/HE observations
  100. IceCube-200117A: Candidate Counterpart from the Zwicky Transient Facility

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