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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').
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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"
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8520 results found.

  1. LIGO/Virgo S190426c: GROWTH India follow-up
  2. LIGO/Virgo S190426c: STARE2 simultaneous L-band radio observations
  3. LIGO/Virgo S190426c: a possible lensed NS-NS merger
  4. LIGO/Virgo S190426c: Tentative Red Transient Candidate from Las Cumbres Observatory
  5. LIGO/Virgo S190426c: Fermi GBM Observations
  6. LIGO/Virgo S190426c: SAO optical observation
  7. LIGO/Virgo S190426c: Identification of a GW compact binary merger candidate
  8. LIGO/Virgo S190426c: HAWC follow-up
  9. LIGO/Virgo S190425z: Keck NIR spectroscopy shows AT2019ebq is a supernova
  10. LIGO/Virgo S190425z: Nearby Galaxies in the Updated Localization Volume
  11. LIGO/Virgo S190426c: IceCube Neutrino Search
  12. LIGO/Virgo S190425z: GROND observations of AT2019ebq/PS19qp
  13. LIGO/Virgo S190425z: Updated localization from LIGO and Virgo data
  14. LIGO/Virgo S190425z: AMI-LA radio observations of two ZTF afterglow candidates.
  15. LIGO/Virgo S190425z: GOTO observations
  16. LIGO/Virgo GW190425z: GTC spectroscopic classification of AT2019ebq/PS19qp
  17. LIGO/Virgo S190425z: CALET Observations
  18. LIGO/Virgo S190425z: KMTNet Observation
  19. LIGO/Virgo S190425z - ePESSTO+ NTT spectrum of candidate PS19qo
  20. LIGO/Virgo S190425z - ePESSTO+ NTT observations
  21. LIGO/Virgo S190425z: ZTF19aarykkb Imaging from Las Cumbres Observatory
  22. LIGO/Virgo S190425z - GROWTH-India follow-up of two ZTF candidates
  23. LIGO/Virgo S190425z - HCT spectroscopy
  24. LIGO/Virgo S190425z: STARE2 simultaneous L-band radio observations
  25. LIGO/Virgo S190425z: CLU/NED Galaxies in the Localization Volume
  26. LIGO/Virgo S190425z: ZTF19aarzaod Imaging from Las Cumbres Observatory
  27. LIGO/Virgo S190425z: Lulin Follow-Up Observations
  28. LIGO/Virgo S190425z: Fermi GBM Observations
  29. LIGO/Virgo S190425z: SQUEAN Observation
  30. LIGO/VIRGO S190425z: IceCube Neutrino Search
  31. LIGO/Virgo S190421ar: Fermi-LAT search for a high-energy gamma-ray counterpart
  32. LIGO/VirgoS190425z: HAWC follow-up
  33. LIGO/Virgo S190425z: INTEGRAL prompt observation
  34. LIGO/Virgo S190425z: Identification of a GW compact binary merger candidate
  35. LIGO/Virgo S190421ar/G330308: ANTARES neutrino search
  36. LIGO/Virgo S190408an: Liverpool Telescope follow-up imaging observations
  37. GRB 190422A: Swift detection of a burst
  38. LIGO/Virgo S190421ar: Fermi-GBM Observations
  39. LIGO/Virgo S190421ar: HAWC follow-up
  40. LIGO/VIRGO S190421ar: IceCube Neutrino Search
  41. LIGO/Virgo S190421ar: Identification of a GW compact binary merger candidate
  42. LIGO/Virgo S190408an: INTEGRAL follow-up observations
  43. LIGO/Virgo S190408an: Gaia Photometric Alerts transient candidate
  44. LIGO/Virgo S190412m: GOTO optical coverage - no notable counterparts
  45. LIGO/Virgo S190412m: Fermi-LAT search for a high-energy gamma-ray counterpart
  46. LIGO/Virgo S190412m: Fermi-GBM Observations
  47. LIGO/Virgo S190405ar: Retraction of a GW binary merger candidate
  48. LIGO/Virgo S190408an: Gaia Photometric Alerts transient candidate
  49. LIGO/Virgo S190412m/G329483: ANTARES neutrino search
  50. LIGO-Virgo S190412m: Search for neutrino counterparts with IceCube
  51. LIGO/Virgo S190412m: HAWC follow-up
  52. LIGO/Virgo S190412m: Identification of a GW binary merger candidate
  53. LIGO/Virgo S190408an: GROND Observations of MASTER OT J154209.55-431742.2
  54. IceCube-190331A: Swift-XRT Follow-up Observations
  55. LIGO/Virgo S190408an: DDOTI/OAN Optical Observations
  56. LIGO/Virgo ST190408an: Fermi-LAT search for a high-energy gamma-ray counterpart
  57. GRB 190409A: Swift detection of a possible burst
  58. LIGO/Virgo S190408an: MASTER OT is 27 day old ATLAS SN candidate and unrelated
  59. LIGO/Virgo S190408an: Identification of a GW binary merger candidate
  60. Search for neutrino counterparts to GW candidate S190408an with IceCube
  61. LIGO-Virgo S190408an: HAWC follow-up
  62. GRB 190404C: Swift-XRT observations
  63. GRB 190404B: Tiled Swift observations
  64. LIGO/Virgo: Announcing the start of Observing Run 3 (O3) and the beginning of the public gravitational-wave alert era
  65. Search for additional neutrino events from the direction of IceCube-190331A with IceCube
  66. GRB 190331B: Swift ToO observations
  67. IceCube-190331A - IceCube observation of a high-energy neutrino candidate event
  68. Swift Trigger 895503 is not a GRB
  69. GRB 190326A: Swift-BAT refined analysis - a soft-short GRB or an SGR
  70. Swift Trigger 895257: Detection of GRO J2058+42 in outburst
  71. GRB 190324A: Swift/UVOT afterglow candidate
  72. Swift Trigger 894268: Detection of GRO J2058+42 in outburst
  73. GRB 190311A: Mondy optical observations
  74. GRB 190311A: Swift detection of a burst with optical counterpart
  75. GRB 190306A: Tiled Swift observations
  76. GRB 190305A: Tiled Swift observations
  77. INTEGRAL observation of IceCube-190221A
  78. Search for additional neutrino events from the direction of IceCube-190221A with IceCube
  79. IceCube-190221A: Swift-XRT Follow-up Observations
  80. GRB 190219A: CrAO and AbAO optical upper limit
  81. GRB 190220B: Kitab Observatory optical upper limit
  82. IceCube-190221A - IceCube observation of a high-energy neutrino candidate event
  83. GRB 190220B: BOOTES-4 optical observation
  84. GRB 190219A: NOT optical afterglow candidate
  85. GRB 190220A: Swift detection of a burst with an optical counterpart
  86. GRB 190219A: Swift detection of a burst
  87. GRB 190215A: Fermi GBM detection
  88. Konus-Wind observation of GRB 190206A
  89. GRB 190203A: COATLI Optical Observations
  90. GRB 190204A: COATLI Optical Detection of the Fading Afterglow
  91. GRB 190202A: R and I band observation from HCT
  92. GRB 190204A: Swift detection of a burst with a possible optical counterpart
  93. Swift Trigger 887541: Swift detection of Swift J1728.9-3613
  94. GRB 190203A: Koshka Zeiss-1000 optical upper limit
  95. GRB 190203A: Swift detection of a burst with an optical counterpart
  96. GRB 190202A: Swift detection of a burst with an optical counterpart
  97. Improved IPN error box for GRB 190129B
  98. GRB 190129B: DDOTI Detection of the Possible Afterglow and Suggestion of Fading
  99. GRB 190129B: Swift/UVOT Upper Limits
  100. GRB 190129B: ePESSTO NTT optical observations

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