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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"

3387 results found.

  1. LIGO/Virgo G275697: CALET Observations
  2. LIGO/Virgo G275697: MASTER automatic follow up detection
  3. LIGO/Virgo G275697: CNEOST optical observations
  4. LIGO/Virgo G275697: REM optical/NIR observations
  5. LIGO/Virgo G275404: SVOM/Mini-GWAC: Observations of initial skymap
  6. LIGO/Virgo G274296: GRAWITA-Campo Imperatore observation
  7. GRB 170222A: Swift-XRT observations
  8. IPN Triangulation of GRB 170222A (short/hard)
  9. LIGO/Virgo G274296: J-GEM optical/NIR follow-up observations
  10. LIGO/Virgo G274296: Asiago 1.82m Optical Observations
  11. LIGO/Virgo G274296: PESSTO classification of 9 Pan-STARRS transients
  12. IPN Triangulation of GRB 170219A (short/hard)
  13. LIGO/Virgo G274296: Pan-STARRS imaging and discovery of 70 transients
  14. Konus-Wind observation of GRB 170209A
  15. Correction to GCN 20640: GRB 170208B: GROND observations
  16. GRB 170208B WHT nIR candidate afterglow
  17. GRB 170208B: GROND observations
  18. LIGO/Virgo G270580: Gemini-South Spectroscopic Classification of Optical Transients
  19. GRB 170205A: Swift/UVOT Detection of a Fading Afterglow
  20. GRB 170202A: SMARTS optical/IR afterglow observations
  21. Konus-Wind observation of GRB 170202A
  22. GRB 170205A: Swift detection of a burst with an optical counterpart
  23. GRB 170202A: MITSuME Akeno Optical Observation
  24. GRB 170202A: MASTGlobal ER-Net bright OT nonmonotonic light curve
  25. GRB 170202A: Mini-MegaTORTORA upper limits
  26. GRB 170202A: Swift detection of a burst with an optical afterglow
  27. LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
  28. GRB 170127A: GROND Upper limits
  29. Konus-Wind observation of GRB 170126A
  30. GRB 170127B: Swift detection of a short burst
  31. LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
  32. GRB 170121B: MASTER early optical observations of the Swift possible XT
  33. LIGO/Virgo G270580: ATLAS coverage and 4 optical transients
  34. LIGO/Virgo G270580: Mini-MegaTORTORA follow-up observations
  35. GRB 170113A: Swift detection of a burst with an optical counterpart
  36. GRB 170111A: Swift detection of a burst
  37. Trigger 731535: Swift detection of GRS 1716-249/GRO J1719-24/V2293 Oph
  38. LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
  39. Trigger 731257: Another Swift-BAT detection of GRS 1716-249/GRO J1719-24/V2293 Oph
  40. Trigger 731183: Swift detection of GRS 1716-249/GRO J1719-24/V2293 Oph
  41. LIGO/Virgo G211117 / GW151226: LOFAR follow-up
  42. LIGO/Virgo G268556: observation regions by Project Mini-GWAC of SVOM
  43. GRS 1716-249/GRO J1719-24/V2293 Oph, Swift-BAT refined analysis
  44. GRB 161220A: Swift-BAT refined analysis
  45. IPN Triangulation of GRB 161218B (long/very bright)
  46. GRB 161117A: Swift/UVOT Detection
  47. GRB 161117B: LCO optical observations
  48. GRB 161117A: VLT/X-shooter spectroscopy and redshift
  49. GRB 161117A: Swift detection of a burst with an optical counterpart
  50. GRB 161108A: TSHAO optical observations
  51. GRB 161108A: TAROT Calern observatory optical observations
  52. GRB 160928A: The first GRB detected by POLAR
  53. Konus-Wind observation of GRB 161023A
  54. Konus-Wind observation of GRB 161017A
  55. GRB 161017A: MITSuME Akeno Optical Observation
  56. GRB 161014A: Swift-XRT refined Analysis
  57. GRB 161014A: Swift-BAT refined analysis
  58. GRB 161014A: Swift/UVOT Detection
  59. GRB 161014A: Swift-XRT and UVOT afterglow detection
  60. GRB 161014A : Xinglong TNT optical observation
  61. GRB161014A: optical afterglow candidate with the LCOGT-FTS
  62. GRB 161014A: MITSuME-Akeno optical observation
  63. GRB 161010A: Swift/UVOT Possible Detection
  64. GRB 161007A: MASTER-net early optical observations
  65. GRB 160927A: GTC observations
  66. GRB 161004B: Prompt enhanced Swift-XRT position
  67. GRB 161004A: Swift detection of a burst with a possible optical counterpart
  68. Fermi GBM trigger 496791348/160928900 is not a GRB
  69. GRB160925A / Fermi 496473540: MASTER optical transient confirmation by LCOGT-FTN
  70. GRB160821A: Astrosat CZTI (veto) detection
  71. IPN Triangulation of GRB 160820A (short/hard)
  72. GRB 160816A: TSHAO optical observations
  73. IPN Triangulation of GRB 160806A
  74. GRB 160804A: Swift-BAT refined analysis
  75. GRB 160801A: Swift detection of a burst
  76. HAWC follow up of IceCube 160731
  77. Trigger 706396: Swift detection of a short burst from PSR 1119-6127
  78. Konus-Wind observation of GRB 160720A
  79. GRB 160712A: Global MASTER-Net optical observation
  80. GRB 160628A CALET Gamma-Ray Burst Monitor detection
  81. GRB 160629A: AbAO optical observations
  82. GRB 160703A: Swift-BAT refined analysis
  83. GRB 160629A: AbAO optical observations
  84. GRB 160625B: TSHAO optical observations, correction GCN 19619
  85. IPN Triangulation of GRB 160620A (short/hard)
  86. GRB 160624A: Swift-XRT refined Analysis
  87. GRB 160624A: Swift detection of a short burst
  88. LIGO/Virgo G211117/GW151226: serendipitous XMM-Newton slew observations
  89. IPN Triangulation of GRB 160612A (short/hard)
  90. GRB160611.9 MASTER-Net OT detection
  91. GRB 160601A: AbAO optical observations
  92. FERMI GBM bursts from the magnetar SGR 1935+2154
  93. Trigger 686761: Swift detection of a bright burst from SGR 1935+2154
  94. FACT follow-up of the IceCube event 160427A
  95. GRB 160501A: Swift-BAT refined analysis
  96. MASTER search for counterpart to the IceCube event 67093193 (run 127853)
  97. GRB 160425A MASTER notices: possible host galaxy in the optical error-box
  98. GRB 160425A : MASTER earlier optical observations
  99. LIGO/Virgo G211117: EWE for NOWT of 12 days follow-up of northern sky
  100. GRB 160411A: Fermi GBM detection

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