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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"

23624 results found.

  1. GRB 250114B: Swift-XRT observations
  2. GRB 250114A: LCO optical counterpart detection.
  3. GRB 250114A: GRANDMA/TAROT optical afterglow detection
  4. GRB 250114A: LCOGT optical afterglow i-band detection
  5. GRB 250114B : GIT optical upper limit
  6. EP250111a: SAO RAS optical upper limit
  7. LIGO/Virgo/KAGRA S250114ax: NED Galaxies in the Localization Volume
  8. GRB 250114A: REM detection of the optical and NIR counterpart
  9. LIGO/Virgo/KAGRA S250114ax: Identification of a GW compact binary merger candidate
  10. GRB 250114A: LCO optical observations
  11. GRB 250114A: TRT optical observations
  12. GRB 250114A: Swift detection of a burst with an optical counterpart
  13. EP250108a / AT 2025kg: SAO RAS optical observations
  14. GRB 250107A: VZLUSAT-2 detection
  15. GRB 250109A / EP250109a: GRBAlpha detection
  16. GRB 250107D: GRBAlpha detection
  17. GRB 250106A: Swift-XRT afterglow detection
  18. EP250111a: KAIT optical observations
  19. GRB 250109A / EP250109a: Mephisto optical upper limits
  20. EP250108a: Mephisto detection
  21. EP250108a / AT 2025kg: LCO optical observations
  22. EP250109a/GRB 250109A:SVOM/VT optical counterpart
  23. GRB 250109A / EP250109a: Terskol (INASAN) and SAO RAS observations
  24. GRB 250109A / EP250109a: Swift detection of the X-ray afterglow
  25. GRB 250107D: CALET Gamma-Ray Burst Monitor detection
  26. GRB 250107C: CALET Gamma-Ray Burst Monitor detection
  27. Konus-Wind detection of GRB 250107C
  28. EP-WXT trigger EP250108a：Xinglong optical follow-up observations
  29. EP250108a: EP-FXT follow-up observation
  30. EP-WXT trigger EP250109a：Xinglong optical follow-up observations
  31. GRB 250109a: GMG Optical Upper Limit
  32. EP250109a: Swift/UVOT non-detection
  33. Konus-Wind detection of GRB 250107D (short/hard)
  34. IPN triangulation of GRB 250107C
  35. GRB 250108B: Swift-BAT refined analysis
  36. GRB 250108B: REM optical/NIR upper limits
  37. EP250109a: SVOM/VT optical candidate
  38. EP250109a: GOTO optical upper limits
  39. LIGO/Virgo/KAGRA S250109bi: Identification of a GW compact binary merger candidate
  40. LIGO/Virgo/KAGRA S250109f: Identification of a GW compact binary merger candidate
  41. GRB 250108B: Swift-XRT refined Analysis
  42. GRB 250103A: 1.6m Mephisto optical observations
  43. GRB 250108A: Swift-XRT afterglow detection
  44. GRB 250108A:SVOM/VT optical candidate
  45. LIGO/Virgo/KAGRA S250108eo: Identification of a GW compact binary merger candidate
  46. GRB 250103A: Swift-XRT afterglow detection
  47. GRB 250106A: SVOM/VT 2nd optical deep observation
  48. EPWXT01709129925: Xinglong optical observations
  49. GRB 250103B: REM optical/NIR upper limits
  50. GRB 250101A: REM optical/NIR counterpart detection
  51. GRB 250106A: Swift-XRT observations
  52. GRB 250106A: SVOM/VT optical candidate
  53. GRB 241229A: SVOM/VT optical upperlimit
  54. GRB 250103B: Swift-XRT refined Analysis
  55. GRB 250103A: Swift-XRT observations
  56. GRB 250103B：SVOM/VT optical counterpart
  57. LIGO/Virgo/KAGRA S250104v: Identification of a GW compact binary merger candidate
  58. GRB 250103A: Montarrenti Observatory optical detection
  59. GRB 250101A: further LCOGT optical afterglow observations
  60. GRB 250103A: Redshift 4.01 from OSIRIS+/GTC
  61. GRB 250103A: SVOM/VT optical counterpart confirmation
  62. GRB 250103B: Swift detection of a burst
  63. GRB 250103A: GOTO optical upper limit
  64. GRB 250101A: NUTTelA-TAO / BSTI Optical Limits
  65. GRB 250101A: Swift-BAT refined analysis
  66. GRB 250101A: further SAO RAS optical observations
  67. GRB 250101A: LCO optical counterpart detection
  68. GRB 250101A NUTTelA-TAO / BSTI Early Measurements
  69. GRB 250101A: GMG spectroscopic redshift at z ~ 2.481
  70. GRB 250101A: Swift/UVOT Detection
  71. GRB 250101A: Montarrenti Observatory optical observations and rebrightening
  72. GRB 250101A: LCOGT optical afterglow detection
  73. GRB 250101A: OASDG optical observations
  74. GRB 250101A: SAO RAS observations of optical brightening
  75. GRB 250101A: BOOTES-4/MET optical afterglow detection
  76. GRB 250101A: SAO RAS optical observations
  77. GRB 250101A: Xinglong-2.16m spectroscopic redshift
  78. GRB 250101A: GMG Optical Observation
  79. GRB 250101A: Swift detection of a burst with an optical counterpart
  80. EP241217a: VLA Radio Detection

  81. LIGO/Virgo/KAGRA S241231du: Coverage and upper limit from MAXI/GSC observations
  82. LIGO/Virgo/KAGRA S250101k: Identification of a GW compact binary merger candidate
  83. LIGO/Virgo/KAGRA S241231bg: Updated NED Galaxies in the Localization Volume
  84. LIGO/Virgo/KAGRA S241231bg: NED Galaxies in the Localization Volume
  85. LIGO/Virgo/KAGRA S241231bg: Identification of a GW compact binary merger candidate
  86. GRB 241229B: SAO RAS optical upper limit
  87. GRB 241228B: SAO RAS optical observations
  88. GRB 241229A: SAO RAS optical observations
  89. GRB 241229B: SVOM/VT optical candidate
  90. GRB 241229A: Swift-XRT observations
  91. Konus-Wind detection of GRB 241228A
  92. GRB 241229B: Swift-BAT refined analysis
  93. GRB241229B: UVOT upper limits
  94. GRB 241228B: D50 optical detection
  95. GRB 241228B: Swift-XRT afterglow detection
  96. GRB 241229B: Fermi GBM Observation
  97. GRB 241229B: NUTTelA-TAO / BSTI Optical Limits
  98. GRB 241229A: GOTO optical upper limits
  99. GRB 241228B: LCO optical observation
  100. GRB 241228A: Swift-BAT refined analysis

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