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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"

16141 results found.

  1. GRB 241026A: SAO RAS observations of possible optical afterglow
  2. GRB241025A: 1.3m DFOT optical afterglow detection
  3. EP241021a: optical follow-up observations with Xinglong Observatory
  4. ​GRB 241025A: optical photometry from Konkoly
  5. GRB 241025A: GROWTH-India Telescope optical observations
  6. GRB 241025A: COLIBRÍ Detection of the Afterglow
  7. GRB 241025A: GRANDMA and Kilonova-Catcher optical afterglow detections and upperlimits
  8. EP241021a: Optical and NIR observations of counterpart with the Fraunhofer Telescope at Wendelstein Observatory
  9. EP241021a: Optical and NIR observations of counterpart with the Fraunhofer Telescope at Wendelstein Observatory
  10. EP241021a: optical follow-up observations with the Liverpool Telescope
  11. GRB 241025A : SVOM/VT optical afterglow observations
  12. EP241021a: Liverpool Telescope optical follow-up observations
  13. GRB 241001A: JWST spectroscopic identification of a supernova counterpart
  14. GRB 241025A: NOT spectroscopic redshift of z = 4.20
  15. GRB 241025A: TRT optical afterglow observation
  16. GRB 241025A: Swift detection of a burst with an optical counterpart
  17. EP241021a: GTC OSIRIS+ spectroscopy of the optical counterpart
  18. GRB 241001A: ATCA radio observations
  19. GRB 241010A: VIRT Optical Upper Limit
  20. EP241021a: VLT/FORS2 redshift z = 0.75
  21. EP241021a: SAO RAS optical observations
  22. EP241021a: KAIT optical observations
  23. EP241021a: EP-FXT follow-up observation update
  24. EP241021a: Optical counterpart observations with the Liverpool Telescope
  25. EP241021a: 1.3m DFOT Optical observations
  26. EP241021a: GSP detects optical candidate counterpart
  27. EP241021a: Optical upper limits with Kinder observations
  28. EP241021a: TRT optical observations
  29. GRB 241018A: SVOM/C-GFT optical observations
  30. EP241021a: NOT likely optical counterpart
  31. GRB241017A: 1.3m DFOT optical upper limit
  32. GRB 241018A: 1.3m DFOT Optical upper limit
  33. GRB 241018A: EP-FXT afterglow detection
  34. EP241021a: GOTO optical upper limits
  35. GRB 241018A/sb24101802: Mephisto optical upper limit
  36. GRB 241017A/sb24101702: Mephisto optical upper limit
  37. GRB 241018A: BOOTES-4/MET optical upper limit
  38. GRB 241018A: Mondy optical upper limit
  39. GRB 241018A: GROWTH-India telescope optical upper limit
  40. GRB241018A: XingLong Optical Upper Limit
  41. GRB 241018A: Swift-XRT observations
  42. GRB 241018A: REM optical/NIR upper limits
  43. GRB 241018A: NOT optical observations
  44. GRB 241017A: SVOM/VT follow-up and optical upper limit
  45. GRB 241018A: SVOM/VT follow-up and optical candidate
  46. GRB 241018A: LCO/0.4m optical upper limits
  47. GRB 241006A: VIRT Optical Upper Limit
  48. GRB 240727A: VIRT Optical Upper Limit
  49. GRB241017a: Liverpool Telescope observations of XRT uncatalogued sources
  50. GRB 241017A: GROWTH-India Telescope optical upper limit
  51. GRB 240916A: radio detection with the VLA
  52. GRB 241009A: LCO optical upper limits
  53. GRB 241009A: GRANDMA optical upper limits
  54. GRB 241010A: JinShan optical observations and potential host galaxy
  55. GRB 241010A: J-band observations with WINTER
  56. GRB 241010A: LCO optical observations
  57. GRB 241010A: Swift detection of a burst with an optical counterpart
  58. GRB 241002B: Swift-XRT afterglow detection
  59. GRB 241002A: NOT optical upper limits
  60. IceCube-241006A: No candidates from the Zwicky Transient Facility
  61. GRB 241006A: GRANDMA optical upper limits
  62. EP240930a / GRB 240930B: CrAO ZTSH optical upper limit
  63. GRB 241002B: PRIME near-infrared detection in 3rd epoch
  64. GRB 240910A: LBT optical observations
  65. GRB 241006A: Swift/UVOT Upper Limits
  66. GRB 241006A: SVOM/VT follow-up and optical upper limit
  67. GRB 241001A: Swift-XRT afterglow detection
  68. GRB 240930B: SVOM/C-GFT optical upper limit
  69. GRB 241002B: PRIME near-infrared detection in 2nd epoch
  70. GRB 241002B: Swift-XRT observations
  71. GRB 241002C: SVOM/C-GFT optical upper limit
  72. GRB 241002B: PRIME near-infrared detection
  73. GRB 241001A : SVOM/VT optical detection
  74. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  75. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  76. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  77. GRB 241002C : MITSuME Akeno optical upper limits
  78. NuEm-240926A: Upper limits from a search for coincident neutrino events in IceCube
  79. GRB241001A: REM optical/NIR upper limits
  80. GRB 241002A: Swift/UVOT Upper Limits
  81. EP240930a: Liverpool Telescope observations
  82. GRB 241002A: LCOGT Optical Upper Limits
  83. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  84. GRB 241001A: Swift/UVOT Detection
  85. GRB 241001A: VLT/X-shooter redshift
  86. GRB 241002B: GOTO optical counterpart candidate
  87. EP trigger ID 01709064214: GOTO confirms detection as a flare star
  88. GRB 241001A: Swift-XRT observations
  89. GRB241001A: optical afterglow candidate
  90. GRB 241002A: 1.5m OSN optical upper limit
  91. GRB 241001A: BOOTES-6/DPRT optical upper limit
  92. EP240930a : KAIT optical upper limit
  93. EP240930a: GOTO optical upper limits
  94. GRB 240929A : Leavitt Observatory optical upper limit
  95. GRB 240825A: LBT optical observations
  96. NuEm-240926A / IC240926A: BZQJ0955+4532 ~0.6m optical decay and rebrightening detection by MASTER
  97. GRB 240529A: FRAM-ORM early optical afterglow observations reveal plateau and rebrightening
  98. LIGO/Virgo S240919bn: GOTO optical upper limits
  99. EP240913A/GRB 240913C: AbAO optical upper limit
  100. EP240919a / GRB 240919A: Mondy optical upper limit

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