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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"

2853 results found.

  1. IceCube-170312A: MASTER follow-up observations
  2. LIGO/Virgo G277583: ATLAS coverage and transients over the first 2 days
  3. GRB 170311A: Swift detection of a burst
  4. GRB170306A: SALT observations
  5. LIGO/Virgo G275404: REM optical/NIR observations
  6. LIGO/Virgo G275404: Swift-XRT sources
  7. LIGO/Virgo G275404: SVOM/Mini-GWAC: Observations of initial skymap
  8. LIGO/Virgo G274296: J-GEM optical/NIR follow-up observations
  9. LIGO/Virgo G274296: iPTF Optical Transient Candidates
  10. LIGO/Virgo G274296: Asiago 1.82m Optical Observations
  11. IPN Triangulation of GRB 170219A (short/hard)
  12. LIGO/Virgo G274296: Pan-STARRS imaging and discovery of 70 transients
  13. Konus-Wind observation of GRB 170207A
  14. IPN Triangulation of GRB 170207A (long/very bright)
  15. LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
  16. GRB 170126A: AstroSat CZTI detection
  17. GRB 170126A: Swift detection of a burst with an optical counterpart
  18. LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
  19. LIGO/Virgo G270580: Observations of initial skymap by Project Mini-GWAC of SVOM
  20. Trigger 731535: Swift detection of GRS 1716-249/GRO J1719-24/V2293 Oph
  21. LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
  22. Trigger 731257: Another Swift-BAT detection of GRS 1716-249/GRO J1719-24/V2293 Oph
  23. Trigger 731183: Swift detection of GRS 1716-249/GRO J1719-24/V2293 Oph
  24. LIGO/Virgo G268556/GW170104: Lomonosov BDRG observations
  25. LIGO/Virgo G268556: ATLAS imaging of the skymap
  26. LIGO/Virgo G211117 / GW151226: LOFAR follow-up
  27. GRS 1716-249/GRO J1719-24/V2293 Oph, Swift-BAT refined analysis
  28. GRB161219.78 MASTER-Net OT detection
  29. GRB 161219B: Watcher optical observations
  30. IPN Triangulation of GRB 161218B (long/very bright)
  31. GRB 161219B: GROND afterglow observations
  32. GRB 161207A: POLAR observation
  33. GRB 161117A: MASTER-OAFA (Argentina) prompt OT observations
  34. GRB 161117B: Enhanced Swift-XRT position
  35. GRB 161117B: Swift detection of a burst
  36. GRB 161113A: Swift-XRT refined Analysis
  37. GRB 161105A: MASTER-IAC early optical observations
  38. GRB 161104A: Swift detection of a short burst
  39. GRB 161017A: MITSuME Akeno Optical Observation
  40. GRB 161007A: MASTER-net early optical observations
  41. GRB 160925A: Kottamia R-band observation
  42. GRB 160917A: Swift/UVOT Detection
  43. GRB 160917A: Mondy optical observations
  44. GRB 160912A: Fermi GBM detection
  45. GRB160821A: Astrosat CZTI (veto) detection
  46. GRB 160816A: MASTER inspection
  47. IPN Triangulation of GRB 160806A
  48. FACT follow-up of IceCube20160731
  49. Swift Trigger 704444 is probably not an astrophysical event.
  50. GRB 160623A: optical astrometry, photometry, and redshift
  51. GRB 160709A CALET Gamma-Ray Burst Monitor detection
  52. IPN Triangulation of GRB 160702A (short/hard)
  53. SGR 1935+2154: CALET Gamma-Ray Burst Monitor detections
  54. GRB 160705B: RATIR Optical and NIR Observations and Confirmation of the Fading Afterglow
  55. GRB 160705B: Swift-BAT refined analysis
  56. GRB 160705B: LT optical candidate
  57. GRB 160705B: Swift detection of a burst
  58. GRB 160625B: RTT150 optical observations
  59. GRB 160625B: Fermi-LAT refined analysis
  60. GRB 160623A: RATIR Optical and NIR Observations, Afterglow Confirmation
  61. GRB 160623A: Mondy optical observations
  62. GRB 160623A: Swift-XRT afterglow detection
  63. Konus-Wind observation of GRB 160607A
  64. GRB160601A: Kanata Telescope I- and Ks-bands upper limits
  65. Another Swift detection of SGR 1935+2154 (trigger #687124)
  66. GRB 160501A MASTER-NET early observations
  67. GRB 160501A: Swift detection of a burst
  68. MASTER search for counterpart to the IceCube event 67093193 (run 127853)
  69. LIGO/Virgo G211117: EWE for NOWT of 12 days follow-up of northern sky
  70. GRB 160412A: Swift detection of a burst
  71. GRB 160410A: GROND optical detection
  72. LIGO/Virgo G211117: LOFAR follow-up
  73. GRB 160324A: CALET Gamma-Ray Burst Monitor detection
  74. GRB 160325A, Swift-BAT refined analysis
  75. GRB 160325A: Swift detection of a burst
  76. GRB 160321A: Swift detection of a probable burst
  77. LIGO/Virgo G211117: EWE for NOWT follow-up of northern sky
  78. Swift detection of a likely new SGR: SGR 0755-2933
  79. GRB 160314A: VLT/X-shooter redshift
  80. Swift trigger 677890 is noise
  81. GRB 160303A, Swift-BAT refined analysis
  82. GRB 160303A: VLT/FORS2 afterglow obervations
  83. GRB 160303A: Swift detection of a burst, possibly short
  84. GRB 160225.81/FERMI Trigg 478121069: MASTER OT J095503.19-355149.4 detection
  85. GRB 160221A: A long GRB detected by INTEGRAL
  86. GRB 160219A: Fermi GBM detection
  87. LIGO/Virgo G211117: LOFAR follow-up
  88. GRB 160131A: Mondy optcial observations
  89. GRB 160127A: TAROT La Silla observatory optical light curve
  90. LIGO/Virgo G211117: Preliminary VLA observation summary of PS15dpn
  91. LIGO/Virgo G211117: Further Swift-XRT sources
  92. LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
  93. GRB 160107A: MAXI/GSC detection
  94. GRB 160104A: MITSuME Okayama upper limits
  95. LIGO/Virgo G211117: Summary of Pan-STARRS transients
  96. LIGO/Virgo G211117: LOFAR follow-up
  97. GRB 160101A: MAXI/GSC detection
  98. LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
  99. LIGO/Virgo G211117: MAGIC very-high energy gamma-ray observations
  100. LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC

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