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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 S230529ay: Updated Sky localization and EM Bright Classification
  2. LIGO/Virgo/KAGRA S230529ay: Identification of a GW compact binary merger candidate
  3. LIGO/Virgo/KAGRA S230518h: Updated Sky localization
  4. LIGO/Virgo/KAGRA S230520ae: Updated Sky localization
  5. LIGO/Virgo/KAGRA S230518h: Upper limits from Glowbug gamma-ray observations
  6. LIGO/Virgo/KAGRA S230518h: TESS observations of the localization region
  7. IceCube-230524A: Upper limits from a search for additional neutrino events in IceCube
  8. LIGO/Virgo/KAGRA S230524x: Retraction of GW compact binary merger candidate
  9. IceCube-230524A - IceCube observation of a high-energy neutrino candidate track-like event
  10. LIGO/Virgo/KAGRA S230522n: Upper limits from IceCube neutrino search
  11. LIGO/Virgo/KAGRA S230522a: 2 counterpart neutrino candidates from IceCube neutrino searches
  12. LIGO/Virgo/KAGRA S230521k: Zwicky Transient Facility observations
  13. IPN triangulation of GRB 230518A (short)
  14. LIGO/Virgo/KAGRA S230520ae: Identification of a GW compact binary merger candidate: End-to-End Test
  15. LIGO/Virgo/KAGRA S230520ae: Upper limits from IceCube neutrino search
  16. LIGO/Virgo/KAGRA S230518h: ATCA follow-up of candidate counterparts
  17. LIGO/Virgo/KAGRA S230518h: Swope Search and Candidate Counterpart Identification
  18. LIGO/Virgo/KAGRA S230518h: Coverage and upper limits from MAXI/GSC observations
  19. LIGO/Virgo/Kagra S230518h: NED Galaxies in the Localization Volume
  20. LIGO/Virgo/KAGRA S230518h: AstroSat CZTI non-detection and upper limits
  21. LIGO/Virgo/KAGRA S230518h: Upper limits from Fermi-GBM Observations
  22. LIGO/Virgo/KAGRA S230518h: Updated Sky localization and EM Bright Classification
  23. LIGO/Virgo S230518h: Upper limits from IceCube neutrino search
  24. LIGO/Virgo/KAGRA S230518h: Identification of a GW compact binary merger candidate
  25. GRB 230513A: Zwicky Transient Facility continuous observations of a Fermi Short GRB (Trigger 705709044)
  26. IPN triangulation of GRB 230512A
  27. GRB 230513A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
  28. GRB 230512A: Nanshan/NEXT non-detection of GRB afterglow candidate
  29. GRB 230512A: Zwicky Transient Facility non-detection of GRB afterglow candidate
  30. GRB 230512A: Liverpool Telescope observations
  31. GRB 230512A: GIT non detection of afterglow candidate
  32. GRB 230512A: Kitab possible afterglow candidate
  33. IceCube-230511A: Upper limits from a search for additional neutrino events in IceCube
  34. IceCube-Cascade 230511A: Upper limits from a search for additional neutrino events in IceCube
  35. GRB 230512A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705565670)
  36. GRB 230430A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 704533643)
  37. GRB 230511D: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705537623)
  38. GRB 230512A: Tiled Swift observations
  39. GRB 230510A: LCOGT Optical Upper Limit
  40. IceCube-230511A: IceCube observation of a high-energy neutrino candidate
  41. GRB 230510A: Swift detection of a burst
  42. IceCube-230506A: Upper limits from a search for additional neutrino events in IceCube
  43. GRB 230506C: Candidate afterglow observation by D50
  44. GRB 230506C: TSHAO possible afterglow candidate
  45. GRB 230506B: Swift/UVOT Detection
  46. IceCube-230506A: IceCube observation of a high-energy neutrino candidate
  47. IceCube-Cascade 230430A: Upper limits from a search for additional neutrino events in IceCube
  48. GRB 230427A: Swift detection of a burst with an optical counterpart
  49. Swift Trigger 1165354 is probably not a GRB
  50. GRB 230420A: Swift detection of a burst
  51. IceCube-Cascade 230417A: Upper limits from a search for additional neutrino events in IceCube
  52. IceCube-230416A: Upper limits from a search for additional neutrino events in IceCube
  53. IceCube-230416A: IceCube observation of a high-energy neutrino candidate
  54. GRB 230414B (correction GRB name in the GCN 33615): Mondy optical afterglow candidate
  55. GRB 230414A: Mondy optical afterglow candidate
  56. GRB 230414B: Swift detection of a burst
  57. IceCube-230405A: BOOTES-4/MET Optical Upper Limits
  58. GRB 230409B: Swift detection of a burst
  59. IceCube-230405A: Upper limits from a search for additional neutrino events in IceCube
  60. GRB 230405B: Swift detection of a burst
  61. GRB 230307A: JWST observations consistent with the presence of a kilonova
  62. IceCube-230405A: IceCube observation of a high-energy neutrino candidate
  63. IceCube-230401A: Upper limits from a search for additional neutrino events in IceCube
  64. IceCube-230401A: IceCube observation of a high-energy neutrino candidate
  65. IceCube-Cascade 230329A: Upper limits from a search for additional neutrino events in IceCube
  66. GRB 230328B: 3.6m DOT multiband optical observation
  67. GRB 230328B: Swift detection of a burst with an optical afterglow
  68. GRB 230322B: Swift-BAT refined analysis
  69. GRB 230325A: Swift detection of a burst
  70. GRB 230322B: Swift detection of a burst with optical counterpart
  71. Trigger 1160641: Swift detection of 4U 1630-472 (a.k.a. SWIFT J1633.8-4724A)
  72. GRB 230307A: INTEGRAL upper limit on Hard X-ray afterglow
  73. GRB 230307A: ATLAS information on the ULTRACAM optical afterglow candidate
  74. GRB 230307A: Erratum of the GCN 33441
  75. GRB 230204B: MASTER detection of an object near NTT Optical Afterglow Candidate
  76. GRB 230307A: optical upper limit
  77. Swift Trigger 1159108 is not a GRB
  78. GRB 230307A: Upper limits from a neutrino search with IceCube
  79. GRB 230307A: Swift-XRT observations
  80. GRB 230307A: Tiled Swift observations
  81. IceCube-230306A: Upper limits from a search for additional neutrino events in IceCube
  82. IceCube-230306A - IceCube observation of a high-energy neutrino candidate
  83. GRB 230228A: Swift detection of a possibly short burst
  84. GRB 230217A: VLT/FORS2 optical observations and candidate counterpart
  85. IceCube-230220A: Upper limits from a search for additional neutrino events in IceCube
  86. IceCube-230217A: Upper limits from a search for additional neutrino events in IceCube
  87. IceCube-230220A - IceCube observation of a high-energy neutrino candidate
  88. IceCube-230217A: BOOTES-4/MET Optical Observations
  89. IceCube-230217A - IceCube observation of a high-energy neutrino candidate track-like event
  90. GRB 230205A: Lowell Discovery Telescope Observations
  91. GRB 230216A: Swift detection of a burst
  92. Swift Trigger 1153670 is probably not a GRB
  93. GRB 230205A: SUBARU HSC pre-imaging for host galaxy search
  94. GRB 230205A: possible host galaxy detection with the Schmidt - Asiago telescope
  95. GRB 230204B: Swift ToO observations
  96. GRB 230205A: Swift detection of a burst
  97. IceCube-230201A: BOOTES-4/MET Optical Upper Limits
  98. GRB 230204B: GIT discovery of the likely optical afterglow
  99. GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
  100. GRB 230204A: Swift detection of a possible burst (or possible transient Swift J1552.8-5055)

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