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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').
Advanced Search

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"
  1. IceCube Alert 241127.59: Global MASTER-Net observations report
  2. GRB 241127A: Swift detection of a burst with an optical counterpart
  3. Swift GRB241127.91: Global MASTER-Net observations report
  4. Swift GRB241127.91: Global MASTER-Net OT detection
  5. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  6. LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
  7. IceCube-241127A: IceCube observation of a high-energy neutrino candidate track-like event
  8. LIGO/Virgo/KAGRA S241127aj: NED Galaxies in the Localization Volume
  9. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations (duplicate submission of 38345)
  10. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations (duplicate submission of 38345).
  11. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations
  12. EP241126a: Optical Upper limits with Kinder observations
  13. SVOM/GRM observation of GRB 241126B or a short burst from magnetar
  14. GRB 241126A: SVOM/GRM observation
  15. IPN triangulation of GRB 241114B
  16. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  17. EP241126a: EP-FXT follow-up observation update
  18. EP241126a: GSP detects optical counterpart
  19. EP241126a: TRT optical counterpart detection
  20. LIGO/Virgo/KAGRA S241127aj: Identification of a GW compact binary merger candidate
  21. EP241126a: EP detection of a fast X-ray transient
  22. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on Optical Counterparts to Two of the Swift/XRT Sources
  23. LIGO/Virgo/KAGRA S241125n: SAGUARO follow-up observations with the MMT
  24. LIGO/Virgo/KAGRA S241126dm: Retraction of GW compact binary merger candidate
  25. Trigger_18947: Swift ToO observations (retracted)
  26. GRB 241113B: EP-FXT afterglow detection
  27. LIGO/Virgo/KAGRA S241125n: DDOTI Optical Upper Limits
  28. LIGO/Virgo/KAGRA S241125n: Gaoyazi/GOT optical observations
  29. SVOM/GRM detection of a short burst from SGR 1830
  30. GECAM detection of a short burst from SGR 1830
  31. LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
  32. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  33. Konus-Wind detection of GRB 241115D / EP 241115a
  34. LIGO/Virgo/KAGRA S241125n: HCT upper limit
  35. LIGO/Virgo/KAGRA S241125n: Upper limits from Konus-Wind observations
  36. GRB 241026A: radio detection with the VLA
  37. EP241125a: Optical upper limit with Kinder observations
  38. EP241125a: EP detection of an X-ray transient
  39. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position
  40. LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
  41. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  42. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  43. LIGO/Virgo/KAGRA S241125n: Updated Sky localization
  44. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  45. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  46. LIGO/Virgo/KAGRA S241109bn: Upper limits from a two-week IceCube neutrino search
  47. LIGO/Virgo/KAGRA S241125n: Updated Sky localization and Coincidence with External Event
  48. LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
  49. GRB 241120A: GRBAlpha detection
  50. GRB 241113B: SVOM/VT optical afterglow observations
  51. LIGO/Virgo/KAGRA S241125n: Identification of a GW compact binary merger candidate
  52. Konus-Wind detection of GRB 241117A
  53. LIGO/Virgo/KAGRA S241122a: Updated Sky localization and Source Classification
  54. GRB 241105A: ATCA radio detection
  55. LIGO/Virgo/KAGRA S241122a: Identification of a GW compact binary merger candidate
  56. IPN triangulation of GRB 241117A
  57. GRB 241026A: VIRT Optical Upper Limit
  58. GRB 241025A: VIRT Optical Upper Limit
  59. Konus-Wind detection of GRB 241120A
  60. GRB241120A: OHP/T193 optical observations
  61. GRB 241120A: CALET Gamma-Ray Burst Monitor detection
  62. EP241021a and EP241026b: Keck/LRIS spectroscopic observations
  63. EP trigger ID 01709065118: Keck/LRIS spectroscopic observations
  64. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
  65. GRB 241120A: Mondy and AbAO optical observations
  66. EP241119a: Optical upper limits with Kinder observations
  67. EP trigger ID 01709122294: the X-ray transient is likely a stellar flare event
  68. EP241119a: GIT optical upper limits
  69. GRB 241113A: Possible ATCA Radio detection
  70. EP241119a : J-band observations with WINTER
  71. GRB 241120A: Fermi GBM Observation
  72. GRB 241114B: Insight-HXMT/HE detection
  73. Integral GRB241120.25: Global MASTER-Net observations report
  74. EP241119a: Global MASTER-Net observations report
  75. EP241119a: EP detection of a fast X-ray transient
  76. GRB241120A: a long GRB detected by INTEGRAL
  77. GRB 241120A: Fermi GBM Final Real-time Localization
  78. GRB 241115A: CALET Gamma-Ray Burst Monitor detection
  79. GRB 241112B: Mephisto further optical observations
  80. GRB 241119A: Fermi GBM Final Real-time Localization
  81. GRB 241030A: J-band observations
  82. GRB 241115a: PRIME near-infrared upper limits
  83. GRB 241117A: Swift/BAT-GUANO localization skymap of a burst
  84. LIGO/Virgo/KAGRA S241116cq: Upper limits from Swift/BAT-GUANO
  85. GRB 241115B: Fermi GBM Observation
  86. LIGO/Virgo/KAGRA S241114y: Updated Sky localization
  87. Fermi GRB 241118A: Global MASTER-Net observations report
  88. GRB 241118A: Fermi GBM Final Real-time Localization
  89. Updates to IceCube realtime alert system for muon tracks
  90. GRB 241117A: SVOM/GRM observation of a short burst with extended emission
  91. GRB 241117A: Fermi GBM Detection
  92. Fermi GRB 241117B: Global MASTER-Net observations report
  93. GRB 241117B: Fermi GBM Final Real-time Localization
  94. IceCube-Cascade 241116A: Upper limits from a search for additional neutrino events in IceCube
  95. LIGO/Virgo/KAGRA S241116cq: Updated Sky localization
  96. GRB 241115B: Swift/BAT-GUANO localization skymap of a long burst
  97. Fermi GRB 241117A: Global MASTER-Net observations report
  98. GRB 241117A: Fermi GBM Final Real-time Localization
  99. GRB 241115C: Fermi GBM Observation
  100. GRB 241115A: Swift-XRT afterglow detection

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