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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"

8474 results found.

  1. LIGO/Virgo/KAGRA S230723ac: Updated Sky localization
  2. LIGO/Virgo/KAGRA S230723ac: Identification of a GW compact binary merger candidate
  3. LIGO/Virgo/KAGRA S230708z: Updated Sky localization
  4. LIGO/Virgo/KAGRA S230715bw: Retraction of GW compact binary merger candidate
  5. IceCube-230707A : MAXI upper limit and NICER follow-up observation of Swift J1753.5-0127
  6. LIGO/Virgo/KAGRA S230709bi: Updated Sky localization
  7. LIGO/Virgo/KAGRA S230708t: Updated Sky localization
  8. IceCube-230708A: Upper limits from Swift/BAT-GUANO
  9. LIGO/Virgo/KAGRA S230712a: Retraction of GW compact binary merger candidate
  10. IceCube-230708A - Correction to GCN Circular 34170
  11. LIGO/Virgo/KAGRA S230708z: Identification of a GW compact binary merger candidate
  12. LIGO/Virgo/KAGRA S230708t: Identification of a GW compact binary merger candidate
  13. LIGO/Virgo/KAGRA S230708cf: Updated Sky localization
  14. GRB 230703A detected with multiple GRID detectors
  15. LIGO/Virgo/KAGRA S230707ai: Updated Sky localization
  16. IceCube-230707A: No candidates from the Zwicky Transient Facility
  17. LIGO/Virgo/KAGRA S230630am: Updated Sky localization
  18. LIGO/Virgo/KAGRA S230630am: Updated Sky localization
  19. IceCube-230708A: Upper limits from a search for additional neutrino events in IceCube
  20. IceCube-230707B: Upper limits from a search for additional neutrino events in IceCube
  21. IceCube-230707A: Upper limits from a search for additional neutrino events in IceCube
  22. LIGO/Virgo/KAGRA S230709bi: Identification of a GW compact binary merger candidate
  23. LIGO/Virgo/KAGRA S230708cf: Identification of a GW compact binary merger candidate
  24. LIGO/Virgo/KAGRA S230708bi: Retraction of GW compact binary merger candidate
  25. IceCube-230708A - IceCube observation of a high-energy neutrino candidate track-like event
  26. IceCube-230707B - IceCube observation of a high-energy neutrino candidate track-like event
  27. IceCube-230707A - IceCube observation of a high-energy neutrino candidate track-like event
  28. LIGO/Virgo/KAGRA S230707ai: Identification of a GW compact binary merger candidate
  29. GRB 230707A: Swift ToO observations
  30. LIGO/Virgo/KAGRA S230706ah: Updated Sky localization
  31. LIGO/Virgo/KAGRA S230704f: Updated Sky localization
  32. LIGO/Virgo/KAGRA S230630bq: Updated Sky localization
  33. LIGO/Virgo/KAGRA S230702an: Updated Sky localization
  34. LIGO/Virgo/KAGRA S230529ay: Updated Sky localization and EM Bright Classification
  35. LIGO/Virgo/KAGRA S230706ah: Identification of a GW compact binary merger candidate
  36. LVK S230619bd/GBM-230619: Upper limits from a two-week IceCube neutrino search
  37. LIGO/Virgo/KAGRA S230704f: Identification of a GW compact binary merger candidate
  38. LIGO/Virgo/KAGRA S230627c: observations of ZTF23aaptsuy/AT2023lx in AbAO observatory
  39. LIGO/Virgo/KAGRA S230702an: Identification of a GW compact binary merger candidate
  40. LIGO/Virgo/KAGRA low-significance gravitational wave candidate S230701z: one counterpart neutrino candidate from IceCube neutrino searches
  41. LIGO/Virgo/KAGRA S230627c: Upper limits from Swift/BAT-GUANO
  42. LIGO/Virgo/KAGRA S230630bq: Identification of a GW compact binary merger candidate
  43. LIGO/Virgo/KAGRA S230630am: Identification of a GW compact binary merger candidate
  44. GRB 230628E - VLT spectroscopic observations
  45. GRB230628E: VLT optical identification of afterglow candidate
  46. LIGO/Virgo/KAGRA S230628ax: Identification of a GW compact binary merger candidate
  47. GRB 230628E: Swift detection of a burst
  48. LIGO/Virgo/KAGRA low-significance gravitational wave candidate S230628aj: one counterpart neutrino candidate from IceCube neutrino searches
  49. LIGO/Virgo/KAGRA S230516az: GOTO candidate counterpart GOTO23hu ruled out by Zwicky Transient Facility observations
  50. LIGO/Virgo/KAGRA S230627c: ATLAS information on the ZTF candidates
  51. LIGO/Virgo/KAGRA S230627c: Upper limits from Fermi-GBM Observations
  52. LIGO/Virgo/Kagra S230627c: NED Galaxies in the Localization Volume
  53. LIGO/Virgo/KAGRA S230627c: Coverage and upper limits from MAXI/GSC observations
  54. LIGO/Virgo/KAGRA S230627c: Updated Sky localization and EM Bright Classification
  55. LIGO/Virgo/KAGRA S230627c: Identification of a GW compact binary merger candidate
  56. LIGO/Virgo/KAGRA S230624av: Updated Sky localization
  57. INTEGRAL upper limit on any GRB associated with ZTF23aaoohpy/AT2023lcr
  58. LIGO/Virgo/KAGRA S230624av: Identification of a GW compact binary merger candidate
  59. IceCube-Cascade 230622A: Upper limits from a search for additional neutrino events in IceCube
  60. GRB 230623A: Tiled Swift observations
  61. GRB 230623A: Tiled Swift observations
  62. LIGO/Virgo/KAGRA S230615az: LBT spectroscopic classification of GOTO23hn
  63. LIGO/Virgo/KAGRA S230622ba: Retraction of GW compact binary merger candidate
  64. LIGO/Virgo/KAGRA S230615az: LBT spectroscopic redshift of the host galaxy of GOTO23hn
  65. Fermi GBM-230619: AstroSat CZTI non-detection and upper limits for the sub-threshold candidate
  66. GRB 230622A: Swift detection of a burst
  67. IceCube-Cascade 230621A: Upper limits from a search for additional neutrino events in IceCube
  68. Fermi GBM-230619: A soft subthreshold candidate potentially associated with a subthreshold LIGO/Virgo compact binary merger candidate
  69. LIGO/Virgo/KAGRA S230619bg: one counterpart neutrino candidate from IceCube neutrino searches
  70. LIGO/Virgo/KAGRA S230615az: Wendelstein observations of DESI galaxies and GIT candidates
  71. ZTF23aaoohpy/AT2023lcr: GROWTH-India Telescope follow-up observations
  72. ZTF23aaoohpy/AT2023lcr: GOTO early optical observations and constraint
  73. ZTF23aaoohpy/AT2023lcr: Zwicky Transient Facility discovery of a fast fading red transient
  74. GRB 230618A: Swift detection of a burst
  75. GRB 230616A: Swift ToO observations
  76. LIGO/Virgo/KAGRA S230615az: T80S Search and Candidate Counterpart Identification
  77. LIGO/Virgo/KAGRA S230615az: Xinglong-2.16m photometric observations of GIT candidates
  78. LIGO/Virgo/KAGRA S230529ay: Upper limits from a two-week IceCube neutrino search
  79. LIGO/Virgo/KAGRA S230615az: GOTO candidate counterparts
  80. IceCube-Cascade 230610A: Upper limits from a search for additional neutrino events in IceCube
  81. LIGO/Virgo/KAGRA S230608as: Updated Sky localization
  82. LIGO/Virgo/KAGRA S230606d: Updated Sky localization
  83. LIGO/Virgo/KAGRA S230609u: Updated Sky localization
  84. LIGO/Virgo/KAGRA S230609u: Identification of a GW compact binary merger candidate
  85. ZTF23aamxeqf/AT2023jxk: 1.3m DFOT Optical upper limit
  86. LIGO/Virgo/KAGRA S230608as: Identification of a GW compact binary merger candidate
  87. GRB 230506B: Chandra localization of the X-ray afterglow
  88. ZTF and GIT Observations of the Candidate Optical Afterglow AT2023jxk
  89. LIGO/Virgo/KAGRA S230606d: Identification of a GW compact binary merger candidate
  90. Fermi-LAT gamma-ray observations of IceCube-230603A
  91. LIGO/Virgo/KAGRA S230605o: Updated Sky localization
  92. IceCube-230603A: Upper limits from a search for additional neutrino events in IceCube
  93. LIGO/Virgo/KAGRA S230601bf: Updated Sky localization
  94. LIGO/Virgo/KAGRA S230605o: Identification of a GW compact binary merger candidate
  95. IceCube-230603A - IceCube observation of a high-energy neutrino candidate track-like event
  96. LIGO/Virgo/KAGRA S230518h: Upper limits from a two-week IceCube neutrino search
  97. LIGO/Virgo/KAGRA S230601bf: Identification of a GW compact binary merger candidate
  98. LIGO/Virgo/KAGRA S230529ay: Upper limits from CALET observations.
  99. LIGO/Virgo/KAGRA S230529ay: Coverage and upper limits from MAXI/GSC observations
  100. LIGO/Virgo/KAGRA S230529ay: Upper limits from Fermi-GBM Observations

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