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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').
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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"
  1. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations (duplicate submission of 38345).
  2. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations
  3. EP241126a: Optical Upper limits with Kinder observations
  4. SVOM/GRM observation of GRB 241126B or a short burst from magnetar
  5. GRB 241126A: SVOM/GRM observation
  6. IPN triangulation of GRB 241114B
  7. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  8. EP241126a: EP-FXT follow-up observation update
  9. EP241126a: GSP detects optical counterpart
  10. EP241126a: TRT optical counterpart detection
  11. LIGO/Virgo/KAGRA S241127aj: Identification of a GW compact binary merger candidate
  12. EP241126a: EP detection of a fast X-ray transient
  13. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on Optical Counterparts to Two of the Swift/XRT Sources
  14. LIGO/Virgo/KAGRA S241125n: SAGUARO follow-up observations with the MMT
  15. LIGO/Virgo/KAGRA S241126dm: Retraction of GW compact binary merger candidate
  16. Trigger_18947: Swift ToO observations (retracted)
  17. GRB 241113B: EP-FXT afterglow detection
  18. LIGO/Virgo/KAGRA S241125n: DDOTI Optical Upper Limits
  19. LIGO/Virgo/KAGRA S241125n: Gaoyazi/GOT optical observations
  20. SVOM/GRM detection of a short burst from SGR 1830
  21. GECAM detection of a short burst from SGR 1830
  22. LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
  23. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  24. Konus-Wind detection of GRB 241115D / EP 241115a
  25. LIGO/Virgo/KAGRA S241125n: HCT upper limit
  26. LIGO/Virgo/KAGRA S241125n: Upper limits from Konus-Wind observations
  27. GRB 241026A: radio detection with the VLA
  28. EP241125a: Optical upper limit with Kinder observations
  29. EP241125a: EP detection of an X-ray transient
  30. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position
  31. LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
  32. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  33. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  34. LIGO/Virgo/KAGRA S241125n: Updated Sky localization
  35. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  36. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  37. LIGO/Virgo/KAGRA S241109bn: Upper limits from a two-week IceCube neutrino search
  38. LIGO/Virgo/KAGRA S241125n: Updated Sky localization and Coincidence with External Event
  39. LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
  40. GRB 241120A: GRBAlpha detection
  41. GRB 241113B: SVOM/VT optical afterglow observations
  42. LIGO/Virgo/KAGRA S241125n: Identification of a GW compact binary merger candidate
  43. Konus-Wind detection of GRB 241117A
  44. LIGO/Virgo/KAGRA S241122a: Updated Sky localization and Source Classification
  45. GRB 241105A: ATCA radio detection
  46. LIGO/Virgo/KAGRA S241122a: Identification of a GW compact binary merger candidate
  47. IPN triangulation of GRB 241117A
  48. GRB 241026A: VIRT Optical Upper Limit
  49. GRB 241025A: VIRT Optical Upper Limit
  50. Konus-Wind detection of GRB 241120A
  51. GRB241120A: OHP/T193 optical observations
  52. GRB 241120A: CALET Gamma-Ray Burst Monitor detection
  53. EP241021a and EP241026b: Keck/LRIS spectroscopic observations
  54. EP trigger ID 01709065118: Keck/LRIS spectroscopic observations
  55. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
  56. GRB 241120A: Mondy and AbAO optical observations
  57. EP241119a: Optical upper limits with Kinder observations
  58. EP trigger ID 01709122294: the X-ray transient is likely a stellar flare event
  59. EP241119a: GIT optical upper limits
  60. GRB 241113A: Possible ATCA Radio detection
  61. EP241119a : J-band observations with WINTER
  62. GRB 241120A: Fermi GBM Observation
  63. GRB 241114B: Insight-HXMT/HE detection
  64. Integral GRB241120.25: Global MASTER-Net observations report
  65. EP241119a: Global MASTER-Net observations report
  66. EP241119a: EP detection of a fast X-ray transient
  67. GRB241120A: a long GRB detected by INTEGRAL
  68. GRB 241120A: Fermi GBM Final Real-time Localization
  69. GRB 241115A: CALET Gamma-Ray Burst Monitor detection
  70. GRB 241112B: Mephisto further optical observations
  71. GRB 241119A: Fermi GBM Final Real-time Localization
  72. GRB 241030A: J-band observations
  73. GRB 241115a: PRIME near-infrared upper limits
  74. GRB 241117A: Swift/BAT-GUANO localization skymap of a burst
  75. LIGO/Virgo/KAGRA S241116cq: Upper limits from Swift/BAT-GUANO
  76. GRB 241115B: Fermi GBM Observation
  77. LIGO/Virgo/KAGRA S241114y: Updated Sky localization
  78. Fermi GRB 241118A: Global MASTER-Net observations report
  79. GRB 241118A: Fermi GBM Final Real-time Localization
  80. Updates to IceCube realtime alert system for muon tracks
  81. GRB 241117A: SVOM/GRM observation of a short burst with extended emission
  82. GRB 241117A: Fermi GBM Detection
  83. Fermi GRB 241117B: Global MASTER-Net observations report
  84. GRB 241117B: Fermi GBM Final Real-time Localization
  85. IceCube-Cascade 241116A: Upper limits from a search for additional neutrino events in IceCube
  86. LIGO/Virgo/KAGRA S241116cq: Updated Sky localization
  87. GRB 241115B: Swift/BAT-GUANO localization skymap of a long burst
  88. Fermi GRB 241117A: Global MASTER-Net observations report
  89. GRB 241117A: Fermi GBM Final Real-time Localization
  90. GRB 241115C: Fermi GBM Observation
  91. GRB 241115A: Swift-XRT afterglow detection
  92. LIGO/Virgo/KAGRA S241116cq: Identification of a GW compact binary merger candidate
  93. EP241115a/GRB 241115D: Optical upper limits with Kinder observations
  94. GRB 241115A: Mephisto upper limits
  95. GRB 241113B: Mephisto upper limits
  96. EP241115a/GRB 241115D: Swift/XRT follow-up observation
  97. GRB 241115D / EP 241115a: SVOM/GRM observation
  98. The EP-WXT trigger 01709120856 is likely a flaring star
  99. EP241113a: Swift XRT weak detection
  100. GRB 241115A: Fermi GBM Observation

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