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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"

32721 results found.

  1. GRB 241206A: Fermi GBM observation
  2. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  3. GRB 241206B: SVOM/MXT observations: a probable flare from the QSO 1ES 1959+650
  4. GRB 241206B: GWAC-F50A optical upper limit
  5. EP241113a: Keck/LRIS spectroscopic observation and tentative redshift
  6. Fermi GRB 241206A: Global MASTER-Net observations report
  7. EP241201a: 1.6m Mephisto Optical Upper Limits
  8. GRB 241204A: COLIBRÍ Optical Upper Limit
  9. EP241202b: KAIT optical upper limit
  10. GRB 241204A: DDOTI Upper Limits on the Afterglow
  11. GRB 241204A: Fermi GBM Observation
  12. Fermi GRB 241204A: Global MASTER-Net observations report
  13. GRB 241130A: CALET Gamma-Ray Burst Monitor detection
  14. GRB 241128A : RAPAS follow-up observations
  15. GRB 241201A: GRBAlpha detection
  16. EP241202b: Upper limits from Fermi-GBM Observations
  17. IceCube-241127A: No transient candidates from the Zwicky Transient Facility
  18. EP241202b: Kinder optical counterpart candidate
  19. Fermi-GBM Sub-Threshold Detection of GRB 241128A
  20. GRB 241113B : RAPAS follow-up observation
  21. EP241201a: EP-FXT follow-up observations
  22. Konus-Wind detection of GRB 241130A
  23. EP241202b: Global MASTER-Net observations report
  24. EP241201a: BOOTES-5 optical upper limit
  25. EP241201a: NOT optical observations
  26. IPN triangulation of GRB 241130A
  27. GRB 241130A: EIRSAT-1 GMOD Detection
  28. GRB 241128A: Swift/UVOT Upper Limits
  29. IceCube-241127A: Upper limits from a search for additional neutrino events in IceCube
  30. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  31. EP241201a: Kinder optical counterpart candidate
  32. LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
  33. EP241201a: Global MASTER-Net observations report
  34. LIGO/Virgo/KAGRA S241201ac: Updated Sky localization
  35. EP241126a: SOAR observations of the optical counterpart
  36. Fermi GRB 241201A: Global MASTER-Net observations report
  37. EP241126a: 1.6m Mephisto Optical Upper Limits
  38. LIGO/Virgo/KAGRA S241201ac: Identification of a GW compact binary merger candidate
  39. LIGO/Virgo/KAGRA S241130be: Updated Sky localization
  40. IPN triangulation of GRB 241128B
  41. Konus-Wind detection of GRB 241114B
  42. LIGO/Virgo/KAGRA S241130n: Updated Sky localization
  43. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  44. GRB 241128A: AbAO optical upper limit
  45. LIGO/Virgo/KAGRA S241127aj: Updated Sky localization
  46. LIGO/Virgo/KAGRA S241130be: Identification of a GW compact binary merger candidate
  47. LIGO/Virgo/KAGRA S241129aa: Updated Sky localization
  48. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  49. GRB 241128A: Swift-BAT refined analysis
  50. GRB 241127A: Swift-BAT refined analysis
  51. EP241126a: NOT optical observations
  52. GRB 241127A: PRIME near-infrared detection
  53. GRB 241128A: Mondy optical observations
  54. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  55. Swift-XRT observations of IceCube -241127A
  56. Swift GRB 241128A: Global MASTER-Net observations report
  57. Fermi-LAT gamma-ray observations of IceCube-241127A
  58. EP241126a: SVOM/VT observations
  59. LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
  60. GRB 241128A: NOT optical observations
  61. GRB 241128A: LCO optical detection
  62. GRB 241128A: 1.5m OSN optical afterglow detection
  63. LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
  64. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  65. GRB 241127A: Swift/UVOT Detection
  66. GRB 241127A: SVOM/GRM observation
  67. LIGO/Virgo/KAGRA S241127aj: Updated Sky localization
  68. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  69. EP241126a: WFST Observations
  70. LIGO/Virgo/KAGRA S241125n: Update on Coincidence False Alarm Method
  71. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  72. LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
  73. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations (duplicate submission of 38345)
  74. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations (duplicate submission of 38345).
  75. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations
  76. EP241126a: Optical Upper limits with Kinder observations
  77. SVOM/GRM observation of GRB 241126B or a short burst from magnetar
  78. IPN triangulation of GRB 241114B
  79. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  80. EP241126a: EP-FXT follow-up observation update
  81. EP241126a: GSP detects optical counterpart
  82. EP241126a: TRT optical counterpart detection
  83. LIGO/Virgo/KAGRA S241127aj: Identification of a GW compact binary merger candidate
  84. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on Optical Counterparts to Two of the Swift/XRT Sources
  85. LIGO/Virgo/KAGRA S241125n: SAGUARO follow-up observations with the MMT
  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. LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
  92. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  93. Konus-Wind detection of GRB 241115D / EP 241115a
  94. LIGO/Virgo/KAGRA S241125n: HCT upper limit
  95. LIGO/Virgo/KAGRA S241125n: Upper limits from Konus-Wind observations
  96. GRB 241026A: radio detection with the VLA
  97. EP241125a: Optical upper limit with Kinder observations
  98. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position
  99. LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
  100. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event

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