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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').
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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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24598 results found.

  1. GRB 231030B: Fermi GBM Detection
  2. IPN triangulation of GRB 231020A
  3. GRB 231030B: BALROG localization (Fermi Trigger 720388704 / GRB 231030832)
  4. GRB 231028A: Swift-BAT refined analysis
  5. IceCube-231027A: Upper limits from a search for additional neutrino events in IceCube
  6. LIGO/Virgo/KAGRA S231029y: Upper limits from Swift/BAT-GUANO
  7. GRB 231024A: AKO Optical Counterpart Candidate
  8. LIGO/Virgo/KAGRA S231029y: One counterpart neutrino candidate from IceCube neutrino searches
  9. LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
  10. LIGO/Virgo/KAGRA S231029y: Identification of a GW compact binary merger candidate
  11. GRB 231028A: AstroSat CZTI detection
  12. GRB 231028A: Glowbug gamma-ray detection
  13. GRB 231028A: Fermi GBM Detection
  14. LIGO/Virgo/KAGRA S231028bg: Updated Sky localization
  15. LIGO/Virgo/KAGRA S231028bg: Identification of a GW compact binary merger candidate
  16. GRB 231028A: Swift detection of a burst
  17. GRB 231019A: Glowbug gamma-ray detection
  18. GRB 231025A: Fermi GBM Observation
  19. GRB 231024A: Fermi GBM Observation
  20. GRB 231025A: Swift/BAT-GUANO detection of a likely short burst
  21. GRB 231020B: AstroSat CZTI detection
  22. GRB 231024A: GOTO optical counterpart candidate
  23. LIGO/Virgo/KAGRA S231025a: two counterpart neutrino candidates from IceCube neutrino searches
  24. The photometry of the transient in Messier 31 field: GMG observation
  25. GRB 231018A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  26. LIGO/Virgo/KAGRA S231020bw: Upper limits from Swift/BAT-GUANO
  27. LIGO/Virgo/KAGRA S231021az: Coverage and upper limits from MAXI/GSC observations
  28. LIGO/Virgo/KAGRA S231020bw: Updated Sky localization
  29. GRB 231020A: Fermi GBM Detection
  30. GRB 231017A: Mondy optical observations. A possible candidate for an afterglow or host galaxy.
  31. GRB 231019A: VZLUSAT-2 detection
  32. GRB 231018A: VZLUSAT-2 detection
  33. GRB 231020B: BALROG localization (Fermi Trigger 719530557 / GRB 231020900)
  34. LIGO/Virgo/KAGRA S231020ba: Updated Sky localization and EM Bright Classification
  35. GRB 231020A: BALROG localization (Fermi Trigger / GRB 231020790)
  36. LIGO/Virgo/KAGRA S231020ba: Upper limits from Fermi-GBM Observations
  37. GRB 231015A: NuSTAR Detection of Prompt Emission
  38. LIGO/Virgo/KAGRA S231020bw: Identification of a GW compact binary merger candidate
  39. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  40. GRB 231017A: 1.3m DFOT Optical upper limit
  41. LIGO/Virgo/KAGRA S231020ba: Identification of a GW compact binary merger candidate
  42. IceCube-231004A: Upper limits from Fermi-GBM Observations
  43. GRB 231018A: Glowbug gamma-ray detection
  44. IPN triangulation of GRB 231018A
  45. GRB 231017A: Swift/UVOT Upper Limit
  46. GRB 230911C: ATCA detection of possible radio counterpart
  47. GRB 231017A: JinShan optical upper limit
  48. GRB 231018A: GROWTH-India Follow-Up of a Fermi Long GRB
  49. LIGO/Virgo/KAGRA S231018cb: One counterpart neutrino candidate event from an IceCube neutrino search
  50. IC231004A: Classification of AT2023uqf/ZTF23abidzvf as a rapidly-evolving supernova with CSM interaction
  51. GRB 231017A: Las Cumbres optical upper limit
  52. GRB 231015A: Glowbug gamma-ray detection
  53. GRB 231017A: LCOGT Optical Upper Limits
  54. GRB231017A: GROWTH-India upper limits on the optical afterglow
  55. GRB 231015A: AstroSat CZTI detection
  56. GRB 231018A: Fermi GBM Detection
  57. GRB 231017A: Swift-XRT observations
  58. GRB 231018A: BALROG localization (Fermi Trigger / GRB 231018521)
  59. GRB 231017A: Swift/BAT-GUANO candidate arcminute localization of a burst
  60. Fermi-LAT gamma-ray observations of IceCube-231014A
  61. GRB231017A: Fermi GBM Final Localization
  62. IceCube-231014A: Upper limits from a search for additional neutrino events in IceCube
  63. LIGO/Virgo/KAGRA S231014r: Upper limits from Swift/BAT-GUANO
  64. (correction) Discovery of an optical transient with strong flaring activity: a new blazar candidate in the Messier 31 field
  65. Discovery of an optical transient with strong flaring activity: a new blazar candidate in the Messier 31 field.
  66. LIGO/Virgo/KAGRA S231014r: Identification of a GW compact binary merger candidate
  67. GRB 231004A: Glowbug gamma-ray detection
  68. LIGO/Virgo/KAGRA S231001aq: Updated Sky localization
  69. LIGO/Virgo/KAGRA S231005j: Upper limits from Swift/BAT-GUANO
  70. LIGO/Virgo/KAGRA S231008ap: Updated Sky localization
  71. LIGO/Virgo/KAGRA S231008ap: Identification of a GW compact binary merger candidate
  72. IceCube-231004A: Upper limits from a search for additional neutrino events in IceCube
  73. IceCube-231004A: No significant detection in HAWC
  74. Fermi-LAT gamma-ray observations of IceCube-231004A
  75. LIGO/Virgo/KAGRA S231005ah: Updated Sky localization
  76. LIGO/Virgo/KAGRA S231005ah: Identification of a GW compact binary merger candidate
  77. LIGO/Virgo/KAGRA S231005j: Updated Sky localization
  78. LIGO/Virgo/KAGRA S231005j: Identification of a GW compact binary merger candidate
  79. transient AT2023sva: radio observations with AMI-LA
  80. LIGO/Virgo/KAGRA S231001aq: Upper limits from Swift/BAT-GUANO
  81. LIGO/Virgo/KAGRA S230930al: Upper limits from Swift/BAT-GUANO
  82. LIGO/Virgo/KAGRA S230928cb: Upper limits from Swift/BAT-GUANO
  83. GRB 230827B: 10.4m GTC spectroscopic redshift
  84. LIGO/Virgo/KAGRA S231001aq: Updated Sky localization
  85. LIGO/Virgo/KAGRA S230930al: Updated Sky localization
  86. LIGO/Virgo/KAGRA S230928cb: Updated Sky localization
  87. LIGO/Virgo/KAGRA S231001aq: Identification of a GW compact binary merger candidate
  88. LIGO/Virgo/KAGRA S230930al: Identification of a GW compact binary merger candidate
  89. NuEm-230927A: Swift-XRT follow-up
  90. LIGO/Virgo/KAGRA S230928cb: Identification of a GW compact binary merger candidate
  91. AT2023sva / GRB230916B: GIT observations of the afterglow
  92. transient AT2023sva: A Binary Driven Hypernova with a possible associated supernova
  93. LIGO/Virgo/KAGRA S230927be: Updated Sky localization
  94. LIGO/Virgo/KAGRA S230927l: Updated Sky localization
  95. LIGO/Virgo/KAGRA S230927be: Identification of a GW compact binary merger candidate
  96. LIGO/Virgo/KAGRA S230927l: Identification of a GW compact binary merger candidate
  97. LIGO/Virgo/KAGRA S230922q: Updated Sky localization
  98. LIGO/Virgo/KAGRA S230924an: Upper limits from Swift/BAT-GUANO
  99. LIGO/Virgo/KAGRA S230920al: Upper limits from Swift/BAT-GUANO
  100. Title: LIGO/Virgo/KAGRA S230919bj: Upper limits from Swift/BAT-GUANO

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