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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"

44278 results found.

  1. EP241201a: Global MASTER-Net observations report
  2. EP241201a: EP detection of a fast X-ray transient
  3. The EP-WXT trigger 01709126243 is not a real source
  4. GRB 241127B: detection of a long GRB by SVOM/ECLAIRs
  5. GRB241201B: Fermi GBM Final Localization
  6. GRB241201B: Fermi GBM Final Localization
  7. LIGO/Virgo/KAGRA S241201ac: Updated Sky localization
  8. EP241126a: SOAR observations of the optical counterpart
  9. Fermi GRB 241201A: Global MASTER-Net observations report
  10. GRB 241201A: BALROG localization (Fermi Trigger 754757764 / GRB 241201622)
  11. GRB 241130A: Fermi GBM Final Real-time Localization
  12. GRB 241130A: Fermi GBM Final Real-time Localization
  13. EP241126a: 1.6m Mephisto Optical Upper Limits
  14. GRB 241201A: Fermi GBM Final Real-time Localization
  15. LIGO/Virgo/KAGRA S241201ac: Identification of a GW compact binary merger candidate
  16. LIGO/Virgo/KAGRA S241130be: Updated Sky localization
  17. Fermi trigger No 754701230: Global MASTER-Net observations report
  18. IPN triangulation of GRB 241128B
  19. Konus-Wind detection of GRB 241114B
  20. LIGO/Virgo/KAGRA S241130n: Updated Sky localization
  21. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  22. GRB 241128A: AbAO optical upper limit
  23. LIGO/Virgo/KAGRA S241127aj: Updated Sky localization
  24. LIGO/Virgo/KAGRA S241130be: Identification of a GW compact binary merger candidate
  25. LIGO/Virgo/KAGRA S241129aa: Updated Sky localization
  26. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  27. SVOM/GRM observation of a short burst from soft gamma repeater Kes 73
  28. GRB 241128C: SVOM/GRM observation
  29. GRB 241128B: SVOM/GRM observation
  30. GRB 241128A: Swift-BAT refined analysis
  31. GRB 241127A: Swift-BAT refined analysis
  32. EP241126a: NOT optical observations
  33. GRB 241127A: PRIME near-infrared detection
  34. GRB 241128A: Mondy optical observations
  35. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  36. Swift-XRT observations of IceCube -241127A
  37. Swift GRB 241128A: Global MASTER-Net observations report
  38. Fermi-LAT gamma-ray observations of IceCube-241127A
  39. EP241126a: SVOM/VT observations
  40. LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
  41. GRB 241128A: Swift-XRT refined Analysis
  42. GRB 241129A: Fermi GBM Final Real-time Localization
  43. GRB 241128A: Enhanced Swift-XRT position
  44. GRB 241128A: NOT optical observations
  45. GRB 241128A: LCO optical detection
  46. GRB 241128A: 1.5m OSN optical afterglow detection
  47. LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
  48. Fermi trigger No 754492985: Global MASTER-Net observations report
  49. GRB 241128A: Swift-XRT afterglow detection
  50. GRB 241128A: Swift detection of a burst
  51. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  52. GRB 241127A: Swift/UVOT Detection
  53. GRB 241127A: Swift-XRT refined Analysis
  54. GRB 241127A: SVOM/GRM observation
  55. GRB 241127A: Enhanced Swift-XRT position
  56. LIGO/Virgo/KAGRA S241127aj: Updated Sky localization
  57. The EP-WXT trigger 01709125191 is not a real source
  58. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  59. Swift GRB241127.91: Global MASTER-Net OT detection
  60. EP241126a: WFST Observations
  61. LIGO/Virgo/KAGRA S241125n: Update on Coincidence False Alarm Method
  62. IceCube Alert 241127.59: Global MASTER-Net observations report
  63. GRB 241127A: Swift detection of a burst with an optical counterpart
  64. Swift GRB241127.91: Global MASTER-Net observations report
  65. Swift GRB241127.91: Global MASTER-Net OT detection
  66. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  67. LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
  68. IceCube-241127A: IceCube observation of a high-energy neutrino candidate track-like event
  69. LIGO/Virgo/KAGRA S241127aj: NED Galaxies in the Localization Volume
  70. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations (duplicate submission of 38345)
  71. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations (duplicate submission of 38345).
  72. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations
  73. EP241126a: Optical Upper limits with Kinder observations
  74. SVOM/GRM observation of GRB 241126B or a short burst from magnetar
  75. GRB 241126A: SVOM/GRM observation
  76. IPN triangulation of GRB 241114B
  77. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  78. EP241126a: EP-FXT follow-up observation update
  79. EP241126a: GSP detects optical counterpart
  80. EP241126a: TRT optical counterpart detection
  81. LIGO/Virgo/KAGRA S241127aj: Identification of a GW compact binary merger candidate
  82. EP241126a: EP detection of a fast X-ray transient
  83. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on Optical Counterparts to Two of the Swift/XRT Sources
  84. LIGO/Virgo/KAGRA S241125n: SAGUARO follow-up observations with the MMT
  85. LIGO/Virgo/KAGRA S241126dm: Retraction of GW compact binary merger candidate
  86. Trigger_18947: Swift ToO observations (retracted)
  87. GRB 241113B: EP-FXT afterglow detection
  88. LIGO/Virgo/KAGRA S241125n: DDOTI Optical Upper Limits
  89. LIGO/Virgo/KAGRA S241125n: Gaoyazi/GOT optical observations
  90. SVOM/GRM detection of a short burst from SGR 1830
  91. GECAM detection of a short burst from SGR 1830
  92. LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
  93. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  94. Konus-Wind detection of GRB 241115D / EP 241115a
  95. LIGO/Virgo/KAGRA S241125n: HCT upper limit
  96. LIGO/Virgo/KAGRA S241125n: Upper limits from Konus-Wind observations
  97. GRB 241026A: radio detection with the VLA
  98. EP241125a: Optical upper limit with Kinder observations
  99. EP241125a: EP detection of an X-ray transient
  100. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position

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