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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

20966 results found.

  1. LIGO/Virgo G184098: LOFAR follow-up
  2. GRB 151004A: Swift-XRT follow-up observations
  3. Trigger 659734: Swift detection of SAX J1750.8-2900 or other source near Galactic center
  4. LIGO/Virgo G184098: VLA follow-up of iPTF15cyk
  5. LIGO/VIRGO G184098 : PESSTO classifications of PanSTARRS transients in the northern region
  6. GRB 151006A: OSN optical upper limit
  7. GRB 151006A: MITSuME Okayama Ks-band upper-limit
  8. GRB 151006A: Swift/UVOT Upper Limits
  9. LIGO/Virgo G184098: Further VST-ESO PARANAL observations
  10. Trigger 657564 / GRB 151004A: Swift BAT and XRT refined analysis
  11. LIGO/VIRGO G184098 : PESSTO classification of PS15cbm in the northern region
  12. LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
  13. Trigger 657564 / GRB 151004A: Swift/UVOT Upper Limits
  14. Swift Trigger 657564: MASTER-NET early optical observations.
  15. LIGO/Virgo G184098: MASTER OTs detection and Scenario Machine prediction
  16. GRB 151001A: RATIR Observations
  17. GRB 151001B: Swift/UVOT Upper Limits
  18. GRB 151001A: Swift/UVOT Detection
  19. GRB 151001B: MASTER-NET early optical observations.
  20. GRB 150925A: Swift/UVOT Upper Limits
  21. LIGO/Virgo G184098: LOFAR follow-up
  22. LIGO/Virgo G184098: ASKAP followup
  23. LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
  24. LIGO/Virgo G184098: optical transient search with Kiso Schmidt telescope and KWFC on behalf of J-GEM collaboration
  25. LIGO/VIRGO G184098 : classifications of transients from the LSQ observations
  26. LIGO/Virgo G184098: transient search with VISTA
  27. ANTARES neutrino detection: Fermi GBM Observations
  28. LIGO/Virgo G184098: DESGW followup program
  29. LIGO/Virgo G184098: SkyMapper observations
  30. LIGO/Virgo G184098: TAROT network optical observations
  31. LIGO/Virgo G184098: La Silla - QUEST Followup
  32. LIGO/Virgo G184098: Swift follow-up observations
  33. LIGO/Virgo G184098: MWA Followup
  34. LIGO/Virgo G184098: DESGW followup program
  35. LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
  36. LIGO/Virgo G184098: Observations from the TOROS collaboration
  37. LIGO/Virgo G184098: iPTF Optical Transient Candidates
  38. LIGO/Virgo G184098: VST-ESO PARANAL observations
  39. LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
  40. Instructions for reporting follow-up observations related to LIGO/Virgo G184098
  41. LIGO/Virgo G184098: observations by MASTER
  42. LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
  43. LIGO/Virgo G184098: Swift follow-up observations
  44. GRB 150910A: AAO optical observations
  45. GRB150915A : IRSF NIR upper limits
  46. GRB 150915A: NOT observations of a brightening afterglow
  47. GRB 150915A: Swift UVOT upper limits
  48. GRB 150910A: Mt. Terskol observatory optical observations
  49. GRB 150910A: TSHAO optical observations
  50. GRB 150915A: GROND detection of an optical counterpart candidate
  51. GRB 150915A: MASTER-NET optical observations
  52. GRB 150910A: T100 observations
  53. GRB 150911A: GROND Upper Limits
  54. GRB 150910A: Continued RATIR Observations
  55. GRB 150907A: Swift-XRT afterglow detection
  56. GRB 150912A: Swift-XRT and UVOT observations
  57. GRB 150910A: RATIR Observations
  58. GRB 150912A: MASTER-IAC optical observations
  59. GRB 150912A: Swift ToO observations
  60. GRB150910A: P60 Observations
  61. GRB150911A: P60 Observations
  62. GRB 150911A: Swift/UVOT Upper Limits
  63. GRB 150910A: AAO optical observations
  64. GRB 150910A: Chuguev observatory optical observations
  65. GRB 150910A: VLA Detection
  66. GRB 150910A: continued SAO RAS optical observations
  67. GRB150911A MITSuME Okayama Ks-band upper-limit
  68. GRB 150910A: TSHAO optical observations
  69. GRB 150910A: NOT observations of the afterglow
  70. GRB 150910A: MITSuME Okayama Ks-band Observation
  71. GRB 150910A: GROND observation of the afterglow
  72. GRB 150910A: SAO RAS optical photometry
  73. GRB 150910A: Swift/UVOT Detection of a Brightening Afterglow
  74. GRB 150910A: Nanshan optical observations
  75. GRB 150910A: LCOGT FTN afterglow observations
  76. GRB 150910A: KAIT Optical Afterglow Detection
  77. Short GRB 150906B: proximity to NGC 3313 galaxy group
  78. GRB150907A: Swift/UVOT observations
  79. GRB 150907B: MASTER-SAAO early optical observations
  80. GRB 150907B: GROND Upper Limits
  81. GRB 150907B: Swift-XRT observations
  82. GRB 150907A: Swift-XRT observations
  83. GRB 150907A: Tiled Swift observations
  84. GRB 150818A: TSHAO and SAO RAS optical observations
  85. GRB 150902A: Swift-XRT afterglow detection
  86. ANTARES neutrino detection: ANU 2.3m and Kepler K2 Observations of the Swift x-ray source
  87. ANTARES neutrino detection: CAHA photometry & spectroscopy of the Swift source
  88. ANTARES neutrino Alert150901.32 alert and Swift XRT counterpart: MASTER optical observations and new possible candidate
  89. ANTARES neutrino detection and Swift/XRT counterpart: GMG observation
  90. GRB 150902A: Swift/UVOT Upper Limits
  91. GRB 150902A: Swift-XRT observations
  92. GRB 150831A: 9.8 GHz VLA upper limits
  93. GRB 150902A: MASTER-SAAO optical observations
  94. ANTARES neutrino detection and possible Swift X-ray counterpart
  95. GRB 150902A: Swift ToO observations
  96. GRB 150831B: Swift/UVOT Upper Limits
  97. GRB 150821A: Flattening in the UVOT light curve
  98. GRB 150831B: MASTER-IAC early optical observations
  99. GRB 150831A: GROND Upper Limits
  100. GRB 150831A: Swift/UVOT Upper Limits

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