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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"

23603 results found.

  1. GRB 241209A: COLIBRÍ Optical Upper Limit
  2. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  3. GRB 241209A: GRANDMA/TAROT upper limit
  4. GRB 241209A: REM optical/NIR observations
  5. GRB 241209D: Enhanced Swift-XRT position
  6. GRB 241209D: Swift detection of a burst
  7. GRB 241209A: Enhanced Swift-XRT position
  8. GRB 241114B: cubesat Avion detection
  9. GRB 241209A: VLT optical observations
  10. GRB 241209A: GOTO optical upper limits
  11. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  12. EP241208a: EP detection of a fast X-ray transient
  13. GRB 241209A: Swift detection of a short burst
  14. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  15. GRB 241206A: DDOTI Upper Limit on the Afterglow
  16. EP241206a: EP detection of a fast X-ray transient
  17. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  18. EP241113a: Keck/LRIS spectroscopic observation and tentative redshift
  19. EP241201a: 1.6m Mephisto Optical Upper Limits
  20. GRB 241204A: COLIBRÍ Optical Upper Limit
  21. EP241202b: KAIT optical upper limit
  22. LIGO/Virgo/KAGRA S241125n: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes
  23. GRB 241204A: DDOTI Upper Limits on the Afterglow
  24. GRB 241128A : RAPAS follow-up observations
  25. IceCube-241127A: No transient candidates from the Zwicky Transient Facility
  26. EP241202b: Kinder optical counterpart candidate
  27. GRB 241113B : RAPAS follow-up observation
  28. EP241201a: BOOTES-5 optical upper limit
  29. EP241202b: EP detection of a fast X-ray transient
  30. EP241201a: NOT optical observations
  31. IPN triangulation of GRB 241130A
  32. GRB 241130A: EIRSAT-1 GMOD Detection
  33. GRB 241128A: Swift/UVOT Upper Limits
  34. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  35. EP241201a: Kinder optical counterpart candidate
  36. LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
  37. EP241126a: 1.6m Mephisto Optical Upper Limits
  38. LIGO/Virgo/KAGRA S241201ac: Identification of a GW compact binary merger candidate
  39. IPN triangulation of GRB 241128B
  40. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  41. GRB 241128A: AbAO optical upper limit
  42. LIGO/Virgo/KAGRA S241130be: Identification of a GW compact binary merger candidate
  43. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  44. GRB 241128A: Swift-BAT refined analysis
  45. GRB 241127A: PRIME near-infrared detection
  46. GRB 241128A: Mondy optical observations
  47. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  48. Swift-XRT observations of IceCube -241127A
  49. EP241126a: SVOM/VT observations
  50. LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
  51. GRB 241128A: Enhanced Swift-XRT position
  52. GRB 241128A: NOT optical observations
  53. GRB 241128A: LCO optical detection
  54. GRB 241128A: Swift-XRT afterglow detection
  55. GRB 241128A: Swift detection of a burst
  56. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  57. GRB 241127A: Swift/UVOT Detection
  58. GRB 241127A: SVOM/GRM observation
  59. GRB 241127A: Enhanced Swift-XRT position
  60. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  61. EP241126a: WFST Observations
  62. LIGO/Virgo/KAGRA S241125n: Update on Coincidence False Alarm Method
  63. GRB 241127A: Swift detection of a burst with an optical counterpart
  64. Swift GRB241127.91: Global MASTER-Net OT detection
  65. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  66. LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
  67. LIGO/Virgo/KAGRA S241127aj: NED Galaxies in the Localization Volume
  68. EP241126a: Optical Upper limits with Kinder observations
  69. IPN triangulation of GRB 241114B
  70. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  71. EP241126a: TRT optical counterpart detection
  72. LIGO/Virgo/KAGRA S241127aj: Identification of a GW compact binary merger candidate
  73. EP241126a: EP detection of a fast X-ray transient
  74. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on Optical Counterparts to Two of the Swift/XRT Sources
  75. LIGO/Virgo/KAGRA S241125n: SAGUARO follow-up observations with the MMT
  76. LIGO/Virgo/KAGRA S241125n: DDOTI Optical Upper Limits
  77. LIGO/Virgo/KAGRA S241125n: Gaoyazi/GOT optical observations
  78. LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
  79. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  80. LIGO/Virgo/KAGRA S241125n: HCT upper limit
  81. GRB 241026A: radio detection with the VLA
  82. EP241125a: Optical upper limit with Kinder observations
  83. EP241125a: EP detection of an X-ray transient
  84. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position
  85. LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
  86. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  87. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  88. LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
  89. GRB 241120A: GRBAlpha detection
  90. LIGO/Virgo/KAGRA S241125n: Identification of a GW compact binary merger candidate
  91. LIGO/Virgo/KAGRA S241122a: Identification of a GW compact binary merger candidate
  92. IPN triangulation of GRB 241117A
  93. GRB 241026A: VIRT Optical Upper Limit
  94. GRB 241025A: VIRT Optical Upper Limit
  95. GRB241120A: OHP/T193 optical observations
  96. EP241021a and EP241026b: Keck/LRIS spectroscopic observations
  97. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
  98. GRB 241120A: Mondy and AbAO optical observations
  99. EP241119a: Optical upper limits with Kinder observations
  100. EP trigger ID 01709122294: the X-ray transient is likely a stellar flare event

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