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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.

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

16293 results found.

  1. LIGO/Virgo S190426c: Swift rapid follow-up observations of S190425z and S190426c and URL for observation log for all future events
  2. LIGO/Virgo S190426c: GROWTH India follow-up of GRAWITA transient
  3. LIGO/Virgo S190412m: Further J-GEM optical/NIR observations
  4. LIGO/Virgo S190425z: 1.3-m optical imaging of UVOT transient field
  5. LIGO/Virgo S190426c: YAHPT Optical Observation
  6. LIGO/Virgo S190425z: KPED Follow-Up of ZTF transients
  7. LIGO/Virgo S190425z: MASTER detection of the faint flare in SDSS Seyfert galaxy z = 0.09
  8. LIGO/Virgo S190426c: Continued LOAO Observation
  9. GRB 190427A: Swift/UVOT Upper Limits
  10. LIGO/Virgo S190426c: Additional Candidates from the Zwicky Transient Facility
  11. LIGO/Virgo S190426c: Continued infrared wide-field search with Palomar Gattini-IR
  12. LIGO/Virgo S190425z: MASTER explanation of the nature of an optical flash detected by a Swift as a short flare on a fast-moving WISE brown
  13. LIGO/Virgo S190426c: ASAS-SN observations
  14. LIGO/Virgo S190426c: LOAO Observation
  15. LIGO/Virgo S190425z: KPED Follow-Up of ZTF transients
  16. LIGO/Virgo S190425z: NOT photometry of ZTF19aasckkq
  17. LIGO/Virgo S190426c: DG19ytre and DG19kplb 1.5m OSN imaging and 10.4m GTC spectroscopy
  18. LIGO/Virgo S190425z: Liverpool Telescope imaging of ZTF19aasckkq
  19. LIGO/Virgo S190425z: No Optical Detection of the Swift/UVOT Transient in ASAS-SN observations hours before and after discovery
  20. LIGO/Virgo S190425z: Additional Candidates from the Zwicky Transient Facility
  21. LIGO/Virgo S190426c: DDOTI/OAN Optical Observations
  22. LIGO/Virgo S190425z: ASAS-SN observations
  23. LIGO/Virgo S190425z: No Optical Detection of the Swift/UVOT Transient with Las Cumbres Observatory
  24. LIGO/Virgo S190425z: Swift/UVOT and XRT pre-images at the position of the potential Swift/UVOT counterpart
  25. LIGO/Virgo S190426c: RATIR Optical and NIR Observations of Galaxies
  26. LIGO/Virgo S190426c: J-GEM optical/NIR follow-up observations
  27. LIGO/Virgo S190426c: COATLI Optical Observations of Galaxies
  28. LIGO/Virgo S190426c: GOTO optical coverage - no notable counterparts
  29. GRB 190427A: Lick/Nickel telescope optical observations
  30. GRB 190427A: MITSuME Akeno optical upper limits
  31. GRB 190427A: COATLI Optical Observations
  32. LIGO/Virgo S190426c: CNEOST Optical Observations
  33. LIGO/Virgo S190425z: CNEOST Optical Observations
  34. LIGO/Virgo S190426c: Optical Wide-field Search with the Zwicky Transient Facility
  35. GRB 190427A: RATIR Optical and NIR Observations
  36. LIGO/Virgo S190426c: Nanshan/NEXT Observation of Galaxies
  37. LIGO/Virgo S190426c: Hobby-Eberly Telescope VIRUS observations of target galaxies.
  38. GRB 190427A: BOOTES-1 and BOOTES-5/JGT early follow-up observations
  39. GRB 190427A: NOT optical observations
  40. LIGO/Virgo S190426c: Public DECam Observations
  41. LIGO/Virgo S190425z: GRAWITA LBT spectroscopic observations
  42. LIGO/Virgo S190426c: SAO optical observation
  43. LIGO/Virgo S190425z: YAHPT Optical Observation
  44. LIGO/Virgo S190425z: J-GEM spectroscopic observations of AT2019ebq/PS19qp with Subaru/FOCAS
  45. LIGO/Virgo S190425z: GROND observations of AT2019ebq/PS19qp
  46. LIGO/Virgo S190425z: TAROT-GRANDMA observation report
  47. LIGO/Virgo S190425z: GOTO observations
  48. LIGO/Virgo GW190425z: GTC spectroscopic classification of AT2019ebq/PS19qp
  49. LIGO/Virgo S190425z: ZTF19aarzaod 1.5m OSN imaging and 10.4m GTC spectroscopy
  50. LIGO/Virgo S190425z: ZTF19aarzaod WHT spectroscopy
  51. LIGO/Virgo S190425z: GRAWITA TNG observations of ZTF19aarzaod
  52. LIGO/Virgo S190425z: ZTF19aarykkb Imaging from Las Cumbres Observatory
  53. LIGO/Virgo S190425z: KPED Follow-Up Observations
  54. LIGO/Virgo S190425z: ZTF19aarzaod Imaging from Las Cumbres Observatory
  55. LIGO/Virgo S190425z: Lulin Follow-Up Observations
  56. LIGO/Virgo S190425z: J-GEM optical follow-up observations with Subaru/FOCAS
  57. LIGO/Virgo S190425z: Xinglong/Schmidt follow-up observations
  58. LIGO/Virgo S190425z: LOAO Observation
  59. LIGO/Virgo S190421ar: TAROT-GRANDMA observation report.
  60. GRB 190422A: Swift/UVOT Upper Limits
  61. Fermi trigger 576241792 / GRB 190406B: MASTER optical observation
  62. GRB 190406B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 576241792)
  63. LIGO/Virgo S190412m: GOTO optical coverage - no notable counterparts
  64. LIGO/Virgo S190412m: J-GEM optical/NIR follow-up observations
  65. LIGO/Virgo S190412m: MASTER early alert observation
  66. GRB 190409A: ground analysis reveals a likely spurious event
  67. LIGO/Virgo S190408an: MASTER OT J231043.63+470956.4 BOOTES-4 and 10.4m GTC follow-up observations
  68. LIGO/Virgo S190408an: GRAWITA optical observations of MASTER OT J231043.63+470956.4
  69. GRB 190404C: MITSuME Akeno and Okayama optical upper limits
  70. LIGO/Virgo S190408an: TMTS Optical Observation
  71. LIGO/Virgo S190408an: DDOTI/OAN Optical Observations
  72. LIGO/Virgo S190408an: HMT optical observations
  73. LIGO/Virgo S190408an: MASTER 3 OT's more detection
  74. LIGO/Virgo S190408an: MASTER OT is 27 day old ATLAS SN candidate and unrelated
  75. LIGO/Virgo S190408an: MASTER OT detection
  76. LIGO/Virgo S190408an: MASTER Global Robotic Net optical observations
  77. LIGO-Virgo GW S190408an: J-GEM optical/NIR follow-up observations
  78. Fermi TriggNum 576054086 (GRB 1904204.29) / MASTER OT J071404.52+550304.2: CrAO optical observations
  79. Hard Fermi GRB190404.29/TriggNum576054086: MASTER optical counterpart discovery near PGC020455
  80. GRB 190404C: Swift-XRT observations
  81. GRB190404C: GROWTH-India discovery of optical counterpart
  82. GRB 190330A: MITSuME Akeno and Okayama optical upper limits
  83. GRB 190331B: BOOTES-3/YA optical observations
  84. IceCube-190331A: MASTER optical follow-up observations
  85. GRB 190326A: 2.2m CAHA telescope optical limit
  86. GRB 190326A: MITSuME Okayama optical upper limits
  87. GRB190324A: MASTER OT observations
  88. GRB 190324A: VLT/X-shooter redshift
  89. GRB 190320A: Swift/UVOT Upper Limits
  90. GRB190320A: MASTER GRB counterpart decay
  91. GRB190311A: MITSuME Akeno optical observation
  92. Fermi trigger 574140965 / GRB190313.15: MASTER Global Robotic Net optical observation
  93. GRB 190311A: OSN optical afterglow detection
  94. GRB 190311A: Mondy optical observations
  95. GRB 190311A: Liverpool Telescope observations
  96. GRB 190311A: NOT optical counterpart
  97. GRB190305A: MASTER Global Robotic Net optical observation
  98. GRB 190311A: Mondy optical observations
  99. GRB 190311A: GMG observation
  100. GRB 190311A: TSHAO optical observations

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