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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

16154 results found.

  1. GRB170104.78 MASTER-Net OT detection
  2. GRB 161214B: MASTER-Kislovodsk early optical observations
  3. GRB 161214A: MASTER-IAC early optical observations
  4. GRB 161219B: Spectroscopic detection of the associated SN with OSIRIS/GTC
  5. GRB 161224A: TSHAO optical observations
  6. GRB 161224A: Swift/UVOT Upper limits
  7. GRB 161219B: UKIRT near-IR afterglow detection
  8. GRB161219.78 MASTER-Net OT detection
  9. GRB 161219B: Rapid ALMA Observations & Detection
  10. GRB 161219B: SALT observations
  11. GRB 161219B: VLT/X-shooter redshift
  12. GRB 161214B: optical spectroscopy of the foreground SDSS object
  13. GRB 161219B: MITSuME Akeno Optical Observation
  14. GRB 161219B: VLA Detection
  15. GRB 161220A: GROND Upper Limits
  16. GRB 161219B: ISON/Terskol optical observations
  17. GRB 161220A: Swift/UVOT Upper Limits
  18. GRB 161219B: Watcher optical observations
  19. GRB 161219B: LCO Sutherland observations
  20. GRB 161219B: GROND afterglow observations
  21. GRB 161219B: Swift detection of a burst with an optical afterglow
  22. GRB 161218A: TAROT Calern observatory optical observations
  23. GRB 161217A: TAROT Calern observatory optical observations
  24. GRB 161217A: MITSuME Okayama upper limits
  25. GRB 161217A: Swift/UVOT Upper Limits
  26. GRB 161214B: AbAO and ISON/Terskol optical observations
  27. GRB 161214B: Mondy optical observations
  28. IceCube-161210: Kanata/HONIR near-infrared follow-up observation
  29. GRB 161214B: RATIR Optical and Near-Infrared Observations
  30. GRB 161214B: TAROT Calern observatory optical observations
  31. GRB 161214B: Chante-perdrix observatory optical observations
  32. GRB 161214B: Swift/UVOT Observations
  33. GRB 161214B: NOT optical observations, possible counterpart
  34. GRB 161214A: NOT observations of the afterglow
  35. GRB 161214A: GROND afterglow observations
  36. GRB 161214A: TAROT Calern observatory optical observations
  37. GRB 161214A: fading optical afterglow candidate with the LT
  38. GRB 161129A: NOT optical observations and candidate host galaxy
  39. MASTER: Optical Blazar Flare Detection during Fermi trigger 502272781 inspection
  40. GRB 161202A: RATIR Optical and NIR Observations
  41. GRB 161202A: Swift/UVOT Upper Limits
  42. GRB 161202A: MITSuME Okayama upper limits
  43. GRB 161129A: Mondy optical observations
  44. GRB 161129A: ISON/UAFO optical observations
  45. GRB 160821B: HST detection of the optical and IR counterpart
  46. GRB 161129A: MITSuME Okayama Optical Observation
  47. GRB 161129A: Tautenburg Ic-band observations
  48. GRB 161129A: TSHAO optical observations / possible afterglow+host galaxy
  49. GRB 161117A: SMARTS optical/IR afterglow observations
  50. GRB 161117A iTelescope observation
  51. GRB 161117A: MASTER-OAFA (Argentina) prompt OT observations
  52. GRB 161117A: TAROT La Silla observatory optical observations
  53. GRB 161117A: GMG observation limit
  54. GRB 161117B: Swift/UVOT Upper Limits
  55. GRB 161117B: LCO optical observations
  56. GRB161117A: REM optical and NIR afterglow detection
  57. GRB 161117A: VLT/X-shooter spectroscopy and redshift
  58. GRB 161117A: Swift detection of a burst with an optical counterpart
  59. GRB 161113A: Swift/UVOT Upper Limits
  60. GRB 161113A: Kuban State University optical upper limit
  61. GRB 161113A: RATIR Optical and NIR Observations
  62. GRB 161109A: Swift/UVOT Upper Limits
  63. GRB 161104A: Magellan imaging and spectroscopy
  64. GRB 161108A: continued TSHAO optical observations
  65. GRB 161104A: Chandra X-ray observations
  66. GRB 161108A: MITSuME Okayama upper limits
  67. GRB 161108A: TSHAO optical observations
  68. GRB 161108A: Swift/UVOT Upper Limits
  69. GRB 161105A: Swift/UVOT Upper Limits
  70. GRB 161108A: TAROT Calern observatory optical observations
  71. GRB 161105A: TAROT La Silla observatory optical observations
  72. GRB 161108A: NOT redshift
  73. GRB 161108A: NOT candidate afterglow
  74. GRB 161104A: Gemini South optical observations
  75. GRB 161105A: MASTER-IAC early optical observations
  76. GRB 161104A: Swift/UVOT Upper Limits
  77. IceCube-161103: MASTER follow-up observations
  78. GRB 161023A: GROND Observations
  79. GRB 161023A: TAROT La Silla observatory optical observations
  80. GRB 161023A: Zadko observatory - Gingin optical observations
  81. GRB 161023A: Watcher optical observations
  82. GRB 161023A: LCOGT-FTS optical observations
  83. GRB 161023A VLT/X-shooter redshift
  84. GRB 161023A (Integral trigger 7613) MASTER-Net bright OT detection
  85. GRB 161022A: RATIR Optical and NIR Observations
  86. GRB 161022A: Swift/UVOT Upper Limits
  87. GRB 161022A: NOT optical observations
  88. GRB 161022A: TAROT Calern observatory optical observations
  89. GRB 161017A: LT optical observations
  90. GRB161017A optical R band observations with SARA-RM
  91. GRB 161017A: TNG spectroscopy and redshift confirmation
  92. GRB 161017A: GTC additional spectroscopy and refined redshift
  93. GRB 161017A: Lomonosov Gamma Ray and MASTER Optical prompt observations
  94. GRB161017A: optical observations with 1-m LCOGT McDonald
  95. GRB 161017A: TNG optical observations
  96. GRB 161017A: MITSuME Akeno Optical Observation
  97. GRB 161014A: Continued RATIR Optical and NIR Observations
  98. GRB 161015A: Swift/UVOT observations
  99. GRB 161017A: Swift detection of a burst with a bright optical afterglow
  100. GRB161017.74 MASTER-Net OT detection

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