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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

28044 results found.

  1. IceCube-190922A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  2. LIGO/Virgo S190814bv: HST and ALMA observations of the host galaxy of ASKAP J005547-270433 / AT 2019osy
  3. GRB 190919B: LCO Optical Afterglow Detection
  4. GRB 190919B: Swift/UVOT Upper Limits
  5. GRB 190919B: Swift-XRT observations
  6. GRB 190919B: GROND detection of the NIR afterglow
  7. GRB 190919B: A long GRB detected by INTEGRAL
  8. LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019nte host galaxy
  9. LIGO/Virgo S190828l: Updated Sky Localization
  10. LIGO/Virgo S190910h: No significant candidates in TAROT-GRANDMA observations
  11. LIGO/Virgo S190910h: Updated Sky Localization
  12. HAWC-190916A: Upper limits from Insight-HXMT/HE observations
  13. HAWC-190916A: IceCube neutrino search
  14. HAWC-190916A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  15. LIGO/Virgo S190915ak: Updated Sky Localization
  16. LIGO/Virgo S190915ak: No transient candidates in CALET observations
  17. HAWC-190916A: DDOTI Optical Observations
  18. Alert from the HAWC Burst Monitor HAWC-190917A
  19. LIGO/Virgo S190915ak: no counterpart candidates in the Swift/BAT observations
  20. LIGO/Virgo S190915ak: Upper limits from Fermi-GBM Observations
  21. LIGO/Virgo S190915ak: No counterpart candidates in Fermi-LAT observations
  22. LIGO/Virgo S190915ak: Coverage and upper limits from MAXI/GSC observations
  23. GRB 190915A: Insight-HXMT/HE detection
  24. LIGO/Virgo S190915ak : no neutrino counterpart candidate in ANTARES search
  25. LIGO/Virgo S190915ak: Upper Limits from AGILE-GRID observations
  26. LIGO/Virgo S190915ak: No counterpart candidate in AGILE-MCAL observations
  27. LIGO/Virgo S190915ak: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  28. LIGO/Virgo S190915ak: Upper limits from IceCube neutrino searches
  29. LIGO/Virgo S190915ak: Identification of a GW compact binary merger candidate
  30. GRB 190915A: BALROG localization (Fermi Trigger 590219102 / GRB 190915240)
  31. LIGO/Virgo S190814bv: No counterpart candidate after completion of GRAWITA VST-ESO PARANAL transient survey.
  32. LIGO/Virgo S190910h: No counterpart candidates in Fermi-LAT observations
  33. LIGO/Virgo S190910d: No Counterparts in DDOTI/OAN Optical Observations
  34. LIGO/Virgo S190910h: Upper limits from CALET observations.
  35. LIGO/Virgo S190910d: No transient candidates in CALET observations.
  36. LIGO/Virgo S190910d: No neutrino candidates at Pierre Auger Observatory
  37. LIGO/Virgo S190910h: Four additional candidates from the Zwicky Transient Facility
  38. LIGO/Virgo S190910d: Updated Sky Localization
  39. LIGO/Virgo S190910h: no counterpart candidates in the Swift/BAT observations
  40. LIGO/Virgo S190910d: No counterpart candidates in Fermi-LAT observations
  41. LIGO/Virgo S190910h: No counterpart candidates in HAWC observations
  42. LIGO/Virgo S190910h: Upper limits from Fermi-GBM Observations
  43. LIGO/Virgo S190910h: No counterpart candidates in AGILE-MCAL observations
  44. LIGO/Virgo S190910h : no neutrino counterpart candidate in ANTARES search
  45. LIGO/Virgo S190910h: Coverage and upper limits from MAXI/GSC observations
  46. LIGO/Virgo S190910h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  47. LIGO/Virgo S190910h: Upper limits from IceCube neutrino searches
  48. LIGO/Virgo S190910h: Identification of a GW compact binary merger candidate
  49. LIGO/Virgo S190910d: no counterpart candidates in AGILE-GRID observations
  50. LIGO/Virgo S190910d: no counterpart candidates in the Swift/BAT Observations
  51. LIGO/Virgo S190910d: No counterpart candidates in AGILE-MCAL observations
  52. Swift Trigger 924641 is an outburst from MAXI J1807+132
  53. LIGO/Virgo S190910d: Coverage and upper limits from MAXI/GSC observations
  54. LIGO/Virgo S190910d : no neutrino counterpart candidate in ANTARES search
  55. LIGO/Virgo S190910d: Upper limits from Fermi-GBM Observations
  56. LIGO/Virgo S190910d: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  57. ZTF19abvizsw: No counterpart candidates from Swift/BAT targeted search
  58. LIGO/Virgo S190910d: No counterpart candidates in HAWC observations
  59. LIGO/Virgo S190910d: Identification of a GW compact binary merger candidate
  60. LIGO/Virgo S190910d: Upper limits from IceCube neutrino searches
  61. LIGO/Virgo S190814bv: VLA/JAGWAR monitoring of the 50% containment region
  62. ZTF19abvizsw/AT2019pim, search for GRB in SPI-ACS/INTEGRAL data
  63. ZTF19abvizsw: 15GHz observations with AMI
  64. GRB 190823A: Swift-XRT afterglow detection
  65. IPN triangulation of GRB 190906A (short)
  66. LIGO/Virgo S190901ap: ZTF19abwvals is a type-Ia SN near maximum
  67. GRB 180620A: SEDM Observations
  68. LIGO/Virgo S190814bv: GRAWITA VST-ESO PARANAL observations and independent transient candidates discovery.
  69. Konus-Wind observation of GRB 190829A
  70. LIGO/Virgo S190901ap: Dabancheng-0.5m optical observations of AT2019pjv
  71. GRB 190829A: Liverpool Telescope observations of a slow supernova rise
  72. LIGO/Virgo S190901ap: Additional candidates from the Zwicky Transient Facility
  73. ZTF19abvizsw: COATLI Optical Observations
  74. LIGO/Virgo S190901ap: GOTO optical coverage and detection of AT2019pjv
  75. LIGO/Virgo S190901ap: no counterpart candidate in the SVOM/GWAC observations
  76. LIGO/Virgo S190901ap: Upper limits from CALET observations.
  77. GRB 190901A: Insight-HXMT/HE detection
  78. LIGO/Virgo S190901ap: Upper limits from Insight-HXMT/HE observations
  79. Liverpool Telescope observations of ZTF19abvizsw, a candidate untriggered GRB afterglow
  80. GRB 190829A: LCO Optical Afterglow Detection
  81. GRB 190903A: Fermi GBM detection
  82. LIGO/Virgo S190901ap: Additional observations from the Zwicky Transient Facility
  83. LIGO/Virgo S190901ap: GROWTH-India follow-up of ZTF19abvionh
  84. LIGO/Virgo S190901ap: Upper limits from AGILE-GRID observations
  85. LIGO/Virgo S190828l: no counterpart candidate in the SVOM/GWAC observations
  86. LIGO/Virgo S190828j: no counterpart candidate in the SVOM/GWAC observations
  87. LIGO/Virgo S190901ap: No neutrino candidates at Pierre Auger Observatory
  88. LIGO/Virgo S190901ap: No counterpart candidates in Fermi-LAT observations
  89. LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of ZTF19abvionh
  90. LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of target galaxy; no obvious optical counterpart.
  91. LIGO/Virgo S190901ap: no counterpart candidates in the Swift/BAT Observations
  92. LIGO/Virgo S190901ap: Candidates from the Zwicky Transient Facility
  93. LIGO/Virgo S190901ap: Updated Sky Localization
  94. LIGO/Virgo S190901ap: No counterpart candidates in AGILE-MCAL observations
  95. LIGO/Virgo S190901ap: Coverage and upper limits from MAXI/GSC observations
  96. LIGO/Virgo S190901ap : no neutrino counterpart candidate in ANTARES search
  97. LIGO/Virgo S190901ap: Upper limits from Fermi-GBM Observations
  98. Fermi GBM trigger 589060361/190901828 is not a GRB
  99. LIGO/Virgo S190901ap: No counterpart candidates in HAWC observations
  100. LIGO/Virgo S190901ap: Identification of a GW compact binary merger candidate

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