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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"

24794 results found.

  1. GRB 170519A: optical observations
  2. GRB 170519A: Enhanced Swift-XRT position
  3. GRB 170519A: Swift detection of a burst with an optical counterpart
  4. LIGO/Virgo G277583: UH88/SNIFS classification of ATLAS and PS1 transients
  5. GRB 170510A: Swift-XRT afterglow detection
  6. GRB 170516A: Swift-BAT refined analysis
  7. GRB 170516A: Swift-XRT refined Analysis
  8. GRB 170516A: Swift/UVOT Upper Limits
  9. GRB 170516A: Enhanced Swift-XRT position
  10. GRB 170516A: Swift detection of a burst
  11. Swift Trigger AXP CXOU J164710.2-455216: MASTER-OAFA observations
  12. Swift Trigger on AXP CXOU J164710.2-455216
  13. GRB 170514A: Fermi GBM detection
  14. GRB 170510A: Global MASTER Net possible OT observations
  15. LIGO/Virgo G284239: Konus-Wind observations
  16. GRB 170510A: LCO possible counterpart
  17. GRB 170510A: Swift-XRT observations
  18. GRB 170510A: Fermi GBM observation
  19. LIGO/Virgo G284239: H.E.S.S. very-high energy gamma-ray follow-up
  20. LIGO/Virgo G284239: MAXI/GSC observations
  21. Swift Trigger 752193 is not a GRB
  22. LIGO/Virgo G284239: AstroSat CZTI upper limits
  23. GRB 170423A: TAROT Reunion observatory optical observations
  24. Swift XRT observations of GRB 170424A
  25. LIGO/Virgo G284239:SVOM/Mini-GWAC observations of the initial skymap
  26. LIGO/Virgo G284239: HAWC follow-up
  27. LIGO/Virgo G284239: MASTER automatic follow up and synchronous observations
  28. LIGO/Virgo G284239: Fermi-LAT search for a high-energy gamma-ray counterpart
  29. LIGO/Virgo G284239: TZAC TAROT network observations with TRE/TCA/TCH
  30. LIGO/Virgo: G284239 ANTARES search
  31. LIGO/Virgo G284239: Swift/BAT data search
  32. LIGO/Virgo G284239: AGILE GRID observations
  33. LIGO/Virgo G284239: INTEGRAL search for a prompt gamma-ray counterpart
  34. LIGO/Virgo G284239: AGILE MCAL Observations
  35. LIGO/Virgo G284239: IceCube neutrino observations
  36. GRB 170428A: GTC spectroscopic redshift of candidate host galaxy
  37. GRB 170428A: TNG optical observations
  38. GRB 170428A: TAROT La Silla observatory optical observations
  39. GRB 170428A: RATIR Afterglow Confirmation
  40. GRB 170428A: GROND detection of the afterglow
  41. GRB 170428A: Swift/UVOT Upper Limits
  42. GRB 170428A: Xinglong 2.16-m upper limit and host galaxy candidate
  43. GRB 170428A: Swift-XRT refined Analysis
  44. GRB 170428A: Swift-BAT refined analysis
  45. Swift Trigger 750337 is probably a noise fluctuation
  46. GRB 170428A: Swift detection of a short burst
  47. GRB170426.95 MASTER-Net OT detection
  48. Swift Trigger 750096 is probably a noise fluctuation
  49. Swift Trigger 750044 is probably a noise fluctuation
  50. GRB 170424A: LCO Observations
  51. GRB 170419A: Swift/UVOT Upper Limits
  52. GRB 170424A: Fermi GBM detection
  53. GRB 170424A: Fermi-LAT detection
  54. GRB 170419A: LCO Observations
  55. GRB 170423A: Fermi GBM detection
  56. Swift Trigger 748858: AbAO and TSHAO optical observations
  57. Swift Trigger 748858: TAROT La Silla observatory optical observations
  58. Swift Trigger 748858: RATIR Optical and NIR Observations
  59. GRB 170419B, Swift-BAT refined analysis
  60. GRB 170419B: Zadko observatory - Gingin optical observations
  61. GRB 170419A: Zadko observatory - Gingin optical observations
  62. GRB 170419A: Swift-XRT refined Analysis
  63. GRB 170419B: Fermi GBM observation
  64. GRB 170419A: Swift-BAT refined analysis
  65. Swift trigger 748858: Swift BAT, XRT, and UVOT refined analysis
  66. GRB 170419A: Enhanced Swift-XRT position
  67. GRB 170419A: Swift detection of a burst
  68. Swift Trigger 748858: Zadko observatory - Gingin optical observations
  69. Swift Trigger 748858: a possible GRB
  70. GRB 170409A: TAROT Reunion observatory optical observations
  71. GRB 170409A: Fermi GBM Observation
  72. GRB 170409A: Fermi-LAT detection
  73. GRB 170405A: SMARTS optical/IR afterglow observations
  74. GRB 170317A: SAO RAS optical observations
  75. GRB170405A, Swift-UVOT Detection
  76. GRB 170405A, Swift-BAT refined analysis
  77. GRB 170405A: Etelman observatory optical observations
  78. GRB 170405A: Swift-XRT refined Analysis
  79. GRB 170405A: RATIR Optical and NIR Observations
  80. Trigger 745966: Swift detection of 4U1850-03
  81. GRB 170405A: ISON/Terskol optical observations
  82. GRB 170405A: Watcher optical detection
  83. GRB 170405A: Redshift from OSIRIS/GTC
  84. GRB 170405A: TAROT Reunion observatory optical observations
  85. GRB 170405A: Enhanced Swift-XRT position
  86. GRB 170405A: Swift detection of a burst with an optical counterpart
  87. LIGO/Virgo G275697: Update on significance from offline analyses
  88. LIGO/Virgo G275404: Update on significance from offline analyses
  89. LIGO/Virgo G275404: European VLBI Network (EVN) follow-up of the near-IR transient in the AGL J1914+1043 field
  90. GRB 170325A: optical observations, possible OT/host detection
  91. Konus-Wind observation of GRB 170403A (short/hard)
  92. IPN Triangulation of GRB 170403A (short)
  93. GRB 170403A: Fermi GBM observation
  94. IceCube-170321A: Konus-Wind upper limits
  95. Swift Trigger 745090 is a noise trigger near NGC 5195
  96. Fermi-LAT Gamma-ray Observations of IceCube-170321
  97. Swift triggered on SAX J1806.5-221
  98. GRB 170330A: Swift-BAT refined analysis
  99. GRB 170331A: Swift-BAT refined analysis
  100. DOAO 1m telescope V, R, I observation of GRB 170317A

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