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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"

2676 results found.

  1. Fermi trigger No 588100239 Global MASTER-Net observations report
  2. LIGO/Virgo S190814bv: Further Pan-STARRS observations and transient sources
  3. IceCube-190819A - HAWC follow-up
  4. LIGO/Virgo S190814bv: GRAWITA TNG NIR imaging of AT2019nqq and AT2019nqc
  5. LIGO/Virgo S190814bv: Prioritization of Counterpart Candidates based on a Photometric Redshift Analysis by the DECam-GROWTH Team
  6. LIGO/Virgo S190814bv : No Counterpart Candidates in Continued Galaxy Targeted Search with Magellan
  7. S190814bv: MASTER analysis of DECam-GROWTH candidates
  8. GRB 190816A: Swift detection of a burst
  9. LIGO/Virgo S190814bv : No Counterpart Candidates in Galaxy Targeted Search with Magellan
  10. LIGO/Virgo S190814bv: GRAWITA TNG infrared imaging of selected galaxies
  11. Fermi trigger No 587505927 Global MASTER-Net observations report
  12. LIGO/Virgo S190814bv Global MASTER-Net observations report
  13. LIGO/Virgo S190814bv: No counterpart candidates in KAIT observations
  14. LIGO/Virgo S190814bv: no counterpart candidates in Thacher imaging
  15. LIGO/Virgo S190814bv: no counterpart candidates in Swope imaging
  16. LIGO/Virgo S190814bv: no counterpart candidates in Nickel/Direct imaging and non-detections of 2019nmd and 2019nme
  17. LIGO/Virgo S190814bv: KMTNet observation
  18. LIGO/Virgo S190814bv Global MASTER-Net optical observations
  19. LIGO/Virgo S190814bv: Liverpool Telescope imaging of selected galaxies
  20. LIGO/Virgo S190814bv: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  21. IPN triangulation of GRB 190810A (short)
  22. GRB 190810A: Fermi GBM Final Real-time Localization
  23. GRB 190808B: Fermi GBM Final Real-time Localization
  24. Fermi trigger No 586788607 Global MASTER-Net observations report
  25. GRB 190804B: MAXI/GSC detection
  26. Fermi trigger No 586574612 Global MASTER-Net observations report
  27. GRB 190731A: no OT detected by MASTER
  28. Fermi trigger No 586305505 Global MASTER-Net observations report
  29. LIGO/Virgo S190728q: ZTF Forced Photometry for PS1 and DECam-GROWTH optical candidates, and a note on DECam Photometry from GCN 25215
  30. LIGO/Virgo S190728q: Optical transients from Pan-STARRS coverage during first 2 nights
  31. LIGO/Virgo S190728q: No counterpart candidates in KAIT observations
  32. Fermi trigger No 585988241 Global MASTER-Net observations report
  33. LIGO/Virgo S190727h: No counterpart candidates in KAIT observations
  34. GRB 190727B: Swift detection of a burst
  35. GRB 190720A: CALET Gamma-Ray Burst Monitor detection
  36. IPN triangulation of GRB 190720A
  37. LIGO/Virgo S190720a: No counterpart candidates in KAIT observations
  38. GRB 190720A: Fermi GBM detection
  39. GRB 190720A: BALROG localization (Fermi Trigger 585326534 / GRB 190720613)
  40. GRB 190720A: Fermi GBM Final Real-time Localization
  41. LIGO/Virgo S190718y: No counterpart candidates in CNEOST
  42. LIGO/Virgo S190720a Global MASTER-Net observations report
  43. LIGO/Virgo S190718y: No counterpart candidates in KAIT observations
  44. GRB 190719A: Fermi GBM Final Real-time Localization
  45. Swift GRB190718.2 Global MASTER-Net observations report
  46. GRB 190718A: Swift detection of a burst
  47. Fermi trigger No 585007213 Global MASTER-Net observations report
  48. Fermi trigger No 584977168 Global MASTER-Net observations report
  49. Fermi trigger No 584804684 Global MASTER-Net observations report
  50. GRB 190706C: Insight-HXMT/HE detection
  51. IceCube Alert 190712.05 Global MASTER-Net observations report
  52. Fermi trigger No 584590606 Global MASTER-Net observations report
  53. Fermi trigger No 584583925 Global MASTER-Net observations report
  54. Konus-Wind observation of GRB 190706C
  55. GRB 190706C: CALET Gamma-Ray Burst Monitor detection
  56. GRB 190708B: MAXI/GSC detection
  57. IPN triangulation of GRB 190706D (short)
  58. IPN triangulation of GRB 190706C (long/very bright)
  59. LIGO/Virgo S190706ai: No counterpart candidates in KAIT observations
  60. IPN triangulation of GRB 190704A (short)
  61. GRB 190706B: Swift detection of a burst
  62. Fermi trigger No 583854113 Global MASTER-Net observations report
  63. LIGO/Virgo S190630ag: no counterpart candidate in the SVOM/GWAC observations
  64. LIGO/Virgo S190701ah: Coverage and upper limits from MAXI/GSC observations
  65. GRB 190630B: Tien Shan and Koshka Zeiss-1000 optical upper limits
  66. GRB 190630C: ISON-Castelgrande optical upper limit
  67. LIGO/Virgo S190630ag: No counterpart candidates in AGILE-GRID observations
  68. GRB 190701A: MAXI/GSC detection
  69. Fermi trigger No 583567803 Global MASTER-Net observations report
  70. GRB 190627A: Koshka Zeiss-1000 optical counterpart observations
  71. GRB 190627A: Optical imaging and spectroscopy from Calar Alto
  72. Fermi trigger No 583327924 Global MASTER-Net observations report
  73. Fermi trigger No 583221986 Global MASTER-Net observations report
  74. Fermi trigger No 583111521 Global MASTER-Net observations report
  75. Swift GRB190624.86 Global MASTER-Net observations report
  76. Swift trigger 911102: D50 optical limit
  77. Fermi trigger No 582856902 Global MASTER-Net observations report
  78. GRB 190615B: AstroSat CZTI detection
  79. Fermi trigger No 582615488 Global MASTER-Net observations report
  80. Fermi trigger No 582615488 Global MASTER-Net observations report
  81. Fermi trigger No 582596766 Global MASTER-Net observations report
  82. GRB 190615B: Insight-HXMT/HE detection
  83. Fermi trigger No 582115625 Global MASTER-Net observations report
  84. Fermi trigger No 581986074 Global MASTER-Net observations report
  85. GRB 190604A: Insight-HXMT/HE detection
  86. Fermi trigger No 581469752 Global MASTER-Net observations report
  87. GRB 190604A: AstroSat CZTI detection
  88. GRB190604A: BALROG localization (Fermi Trigger 581337762 / GRB 190604446)
  89. GRB 190604A: Fermi GBM Final Real-time Localization
  90. Fermi Fermi trigger No 581002688 Global MASTER-Net observations report
  91. LIGO/Virgo S190521r: CNEOST follow-up observations
  92. LIGO/Virgo S190521g: No optical counterpart from SVOM/GWAC observations.
  93. LIGO/Virgo S190512at: SVOM/GWAC-F60A observations
  94. LIGO/Virgo S190519bj: MAXI/GSC Observations
  95. LIGO/Virgo S190519bj Global MASTER-Net observations report
  96. Fermi GRB190517.81 Global MASTER-Net observations report
  97. LIGO/Virgo S190517h Global MASTER-Net observations report
  98. LIGO/Virgo S190517h: IceCube Neutrino Search
  99. Fermi GRB190514.67 Global MASTER-Net observations report
  100. LIGO/Virgo S190513bm: Lick/KAIT Follow-Up Observations

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