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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"

2934 results found.

  1. IPN Triangulation of GRB 170522B (long/intense)
  2. LIGO/Virgo G277583: UH88/SNIFS classification of ATLAS and PS1 transients
  3. LIGO/Virgo G284239: TZAC TAROT network observations with TRE/TCA/TCH
  4. GRB 170423A: Fermi GBM detection
  5. Swift Trigger 748858: MASTER-OAFA early optical observations
  6. IPN Triangulation of GRB 170403A (short)
  7. DOAO 1m telescope V, R, I observation of GRB 170317A
  8. GRB 170317A: Swift detection of a burst with an optical counterpart
  9. LIGO/Virgo G277583: ERRATUM LV GCN 20871: TAROT Calern (TCA) observations
  10. LIGO/Virgo G277583: TAROT Calern (TCA) observations
  11. LIGO/Virgo G277583: SVOM/Mini-GWAC observations of the initial skymap
  12. LIGO/Virgo G270580: optical observations and classification of PS and MASTER sources
  13. IPN Triangulation of GRB 170305A (short)
  14. LIGO/Virgo G275697: Further Swift-XRT sources
  15. LIGO/Virgo G275697: SVOM/Mini-GWAC observations of the initial skymap
  16. LIGO/Virgo G275697: iPTF Optical Transient Candidates
  17. LIGO/Virgo G275404: iPTF Optical Transient Candidates
  18. LIGO/Virgo G275404: CNEOST optical observations
  19. GRB 170220A: POLAR Observation
  20. LIGO/Virgo G274296: J-GEM optical/NIR follow-up observations
  21. LIGO/Virgo G274296: Asiago 1.82m Optical Observations
  22. LIGO/Virgo G274296: PESSTO classification of 9 Pan-STARRS transients
  23. Konus-Wind observation of GRB 170219A (short/hard)
  24. LIGO/Virgo G274296: Pan-STARRS imaging and discovery of 70 transients
  25. GRB 170210A: POLAR observation
  26. IPN Triangulation of GRB 170210A
  27. GRB 170210A: Fermi GBM observation
  28. Konus-Wind observation of GRB 170209A
  29. GRB 170208A: Swift-BAT refined analysis
  30. GRB 170202A: SQUEAN Observation
  31. LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
  32. GRB 170115B: AGILE/SuperAGILE localisation
  33. LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
  34. LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
  35. GRB 170121B: MASTER early optical observations of the Swift possible XT
  36. LIGO/Virgo G268556/GW170104: MAXI/GSC observations
  37. GRB 170121B/Fermi trigger 506702667 MASTER-Amur OT detection
  38. LIGO/Virgo G270580: Observations of initial skymap by Project Mini-GWAC of SVOM
  39. GRB 170112A : AbAO optical observations
  40. GRB 170113A: Fermi GBM observations
  41. GRB 170112A: MASTER-OAFA (Argentina) early optical observations
  42. LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
  43. LIGO/Virgo G268556/GW170104: Lomonosov BDRG observations
  44. LIGO/Virgo G268556: Continued iPTF Observations and Additional Optical Transient Candidates
  45. LIGO/Virgo G268556: SWASP optical imaging
  46. LIGO/Virgo G211117 / GW151226: LOFAR follow-up
  47. LIGO/Virgo G268556: Swift-XRT sources
  48. GRB 170101B: POLAR observation
  49. GRB 170101B: Lomonosov BDRG gamma ray discovery
  50. GRB 170101B: Astrosat CZTI detection
  51. GRB 170101B: Fermi GBM detection
  52. GRB 161214A: MASTER-IAC early optical observations
  53. GRB161219.78 MASTER-Net OT detection
  54. GRB 161219B: Rapid ALMA Observations & Detection
  55. GRB 161220A: Swift-XRT refined Analysis
  56. GRB 161219B: VLA Detection
  57. GRB 161219B: Swift/UVOT Detection
  58. GRB 161219B: LCO Sutherland observations
  59. GRB 161219B: Enhanced Swift-XRT position
  60. GRB 161219B: Swift detection of a burst with an optical afterglow
  61. GRB 161218A: CALET Gamma-Ray Burst Monitor detection
  62. Konus-Wind observation of GRB 161218A
  63. GRB 161218A: POLAR observation
  64. GRB 161218A: Swift detection of a burst
  65. GRB 161129A: ISON/UAFO optical observations
  66. GRB 161117A: SMARTS optical/IR afterglow observations
  67. GRB 161119A: MASTER-SAAO possible OT detection during Fermi Alert
  68. Konus-Wind observation of GRB 161117A
  69. GRB 161108A: NOT redshift
  70. IceCube-161103: MASTER follow-up observations
  71. GRB 161023A: LCOGT-FTS optical observations
  72. GRB 161023A (Integral trigger 7613) MASTER-Net bright OT detection
  73. Swift Trigger 718766 is not an astrophysical event.
  74. GRB 161017A: Lomonosov Gamma Ray and MASTER Optical prompt observations
  75. GRB 161014A: AROMA-N Optical Observation
  76. GRB 161014A: Swift/UVOT Detection
  77. GRB 161014A : Xinglong TNT optical observation
  78. GRB 161010A: Swift/UVOT Possible Detection
  79. GRB 161010A: Swift-XRT afterglow detection
  80. GRB 160927A: 15 GHz upper limits from AMI
  81. GRB 161001A: MASTER-OAFA and MASTER-SAAO early optical observations
  82. GRB 161001A: GROND afterglow candidate
  83. GRB 161001A: X-shooter spectroscopy, candidate host galaxy and redshift
  84. GRB 161001A: Prompt enhanced Swift-XRT position
  85. GRB 160917A: Fermi GBM observation
  86. GRB 160910A: Swift-XRT afterglow detection
  87. GRB 160910A: Fermi GBM observation
  88. GRB 160905A: Swift detection of a burst with an optical counterpart
  89. Konus-Wind observation of GRB 160821A
  90. GRB 160816A: TSHAO optical observations
  91. BAT detection and localization of GRB 160819A
  92. GRB 160816A: ISON/UAFO optical observations
  93. IceCube 160806A: Lomonosov BDRG gamma ray prompt observations
  94. IPN Triangulation of GRB 160806A
  95. Swift Trigger 707545 is likely 4U 1850-03/GS1843-02
  96. Swift Trigger 707517 is probably not a GRB
  97. IPN Triangulation of GRB 160802A
  98. GRB 160804A: Swift detection of a burst
  99. GRB 160714A: MASTER early optical observations
  100. GRB 160714A: Swift-XRT observations

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