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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"

3926 results found.

  1. LIGO/Virgo G268556: NOWT of EWE, Xinglong 0.6/0.9m, Xuyi 1m optical upper limits of ATLAS17aeu and a reminder of GCN 20394
  2. LIGO/Virgo G268556/GW170104: TNG observations of ATLAS17aeu
  3. LIGO/Virgo G268556: Swift-XRT confirms that ATLAS17aeu is fading in X-rays
  4. LIGO/Virgo G268556: ATLAS17aeu position is consistent with GRB170105A
  5. LIGO/Virgo G268556: Liverpool Telescope Spectroscopy of iPTF candidates
  6. LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
  7. LIGO/Virgo G268556/GW170104: 10.4m GTC spectroscopic observations of iPTF17fs
  8. LIGO/Virgo G268556/GW170104: TNG spectroscopic observations of iPTF17ck and iPTF17dz
  9. LIGO/Virgo G268556: Gemini spectrum and Pan-STARRS observations of ATLAS17aeu
  10. LIGO/Virgo G268556: IPN Triangulation of GRB 170105A (association with ATLAS17aeu)
  11. LIGO/Virgo G268556: GWAC_F60B (60cm) follow-up two events of EWE001 and EWE002
  12. LIGO/Virgo G268556/GW170104: Lomonosov BDRG observations
  13. LIGO/Virgo G268556: Continued iPTF Observations and Additional Optical Transient Candidates
  14. LIGO/Virgo G268556: Swift/UVOT observations of ATLAS17aeu
  15. LIGO/Virgo G268556: CALET Observations
  16. LIGO/Virgo G268556: iPTF Optical Transient Candidates
  17. LIGO/Virgo G268556: VLA follow-up of ATLAS17aeu
  18. LIGO/Virgo G268556: AGILE-GRID preliminary analysis
  19. LIGO/Virgo G268556: EWE001 and EWE002- two events close to GCN 20382 with the skymap
  20. LIGO/Virgo G268556: Palomar 200-inch detects ATLAS17aeu, possible afterglow of GRB070105A?
  21. LIGO/Virgo G268556/GW170104: Global MASTER Net second OT detection
  22. LIGO/Virgo G268556: Swift-XRT detection of ATLAS17aeu
  23. LIGO/Virgo G268556: SWASP optical imaging
  24. LIGO/Virgo G268556/GW170104: Asiago Observations
  25. LIGO/Virgo G268556: Updated sky map from gravitational-wave data
  26. LIGO/Virgo G268556: HAWC follow-up of northern sky
  27. LIGO/Virgo G268556: Pan-STARRS1 observations of the skymap
  28. LIGO/Virgo G268556: ATLAS17aeu - an unusual transient within the skymap
  29. LIGO/Virgo G268556/GW170104: Global MASTER Net observations and first OT detection
  30. LIGO/Virgo G268556: ATLAS imaging of the skymap
  31. LIGO/Virgo G268556: DESGW/DECam observations
  32. LIGO/Virgo G268556: AGILE MCAL and Super-AGILE Observations
  33. LIGO/Virgo G268556: Fermi-LAT search for high-energy gamma-ray counterpart
  34. LIGO/Virgo G268556: Mini-MegaTORTORA follow-up observations
  35. LIGO/Virgo G211117 / GW151226: LOFAR follow-up
  36. LIGO/Virgo G268556: Swift-XRT sources
  37. LIGO/Virgo G268556: ANTARES search
  38. LIGO/Virgo G268556: observation regions by Project Mini-GWAC of SVOM
  39. LIGO/Virgo G268556: INTEGRAL search of temporally coincident prompt hard X-ray emission
  40. LIGO/Virgo G268556: Fermi GBM Observations
  41. LIGO/Virgo G268556: Identification of a GW CBC Candidate
  42. Fermi GBM Observations of IceCube-161103
  43. GRB 160927A: NOT optical observations
  44. IPN Triangulation of GRB 160822A (short/hard)
  45. IPN Triangulation of GRB 160820A (short/hard)
  46. Fermi GBM Observations of IceCube-160806A
  47. LIGO/Virgo G211117 / GW151226: Sky maps and other data available in LOSC
  48. LIGO/Virgo G197392 / LVT151012: Sky maps and other data available in LOSC
  49. LIGO/Virgo G211117/GW151226: serendipitous XMM-Newton slew observations
  50. LIGO/Virgo G211117: Astrosat CZTI upper limits
  51. IceCube-160427A: Fermi GBM Observations
  52. LIGO/Virgo G197392 / LVT151012: Identification of a GW CBC Candidate
  53. LIGO/Virgo G211117: EWE for NOWT of 12 days follow-up of northern sky
  54. LIGO Virgo G211117: Additional MWA Observations
  55. IPN Triangulation of GRB 160406A (short/hard)
  56. LIGO/Virgo G211117: 10.4m GTC follow-up of PS15dpn
  57. LIGO/Virgo G211117: LOFAR follow-up
  58. LIGO/Virgo G211117: CALET GBM Observations
  59. LIGO/Virgo G211117: EWE for NOWT follow-up of northern sky
  60. LIGO/Virgo G194575: EWE for NOWT follow-up of northern sky
  61. LIGO/Virgo G211117: HAWC follow-up of northern sky
  62. LIGO/Virgo G211117: GRAWITA LBT follow-up of PS15dpn
  63. IPN Triangulation of GRB 160225B
  64. IPN Triangulation of GRB 160219A (short/hard)
  65. LIGO/Virgo GW150914
  66. LIGO/Virgo GW150914: BOOTES-3 simultaneous imaging
  67. LIGO/Virgo G184098: MASTER arhival results
  68. LIGO/Virgo G184098: Correction for GCN Circular 18361
  69. LIGO/Virgo G184098: MAXI/GSC search for an X-ray counterpart of GW150914
  70. LIGO/Virgo G211117: LOFAR follow-up
  71. LIGO Virgo G211117: MWA Observations
  72. LIGO/VIRGO G184098: Summary of VLA results for iPTF15cyk
  73. LIGO/Virgo G184098: MASTER final result
  74. LIGO/Virgo G211117: Refined localization from CBC parameter estimation
  75. LIGO/Virgo G211117: Preliminary VLA observation summary of PS15dpn
  76. LIGO/Virgo G211117: Further Swift-XRT sources
  77. LIGO/Virgo G211117: INAF NOT follow-up of PanStarrs candidates
  78. LIGO/Virgo G184098: Refined localizations from CBC parameter estimation
  79. LIGO/Virgo G211117: Updated FAR estimate based on offline re-analysis
  80. LIGO/Virgo G184098: Updated FAR estimate
  81. LIGO/Virgo G211117: Distance estimate from GW data compared to redshift of PS15dpn
  82. LIGO/Virgo G211117: Swift observations of PS15dpn
  83. LIGO/Virgo G211117: iPTF Observations of PS15dpn
  84. LIGO/Virgo G211117: PESSTO classification of MASTER J165420.77-615258
  85. LIGO/Virgo G211117: VLA follow-up
  86. LIGO/Virgo G211117: Pi of the Sky observations
  87. LIGO/Virgo G211117: VISTA imaging
  88. LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
  89. LIGO/Virgo G211117: MASTER OT in ESO138-006 galaxy
  90. LIGO/Virgo G211117: Further Swift-XRT sources
  91. LIGO/Virgo G211117: Liverpool Telescope classification of EM candidates
  92. LIGO/Virgo G211117: Summary of Pan-STARRS transients
  93. LIGO/Virgo G211117: INAF TNG follow-up of Kanata telescope candidate
  94. LIGO/Virgo G211117: Fermi/LAT observations
  95. LIGO/Virgo G211117: Liverpool Telescope classification of EM candidates
  96. LIGO/Virgo G211117: Gemini classification of 7 Pan-STARRS transients
  97. LIGO/Virgo G211117: LOFAR follow-up
  98. LIGO/Virgo G211117: Liverpool Telescope classification of EM candidates
  99. LIGO/Virgo G211117: PESSTO classification of Pan-STARRS transients
  100. LIGO/Virgo G211117: MASTER OTs 26.XII.2015 - 01.I.2016

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