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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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

16119 results found.

  1. EP241021a: EP-FXT follow-up observation update
  2. EP241021a: Optical counterpart observations with the Liverpool Telescope
  3. EP241021a: 1.3m DFOT Optical observations
  4. EP241021a: GSP detects optical candidate counterpart
  5. EP241021a: Optical upper limits with Kinder observations
  6. EP241021a: TRT optical observations
  7. GRB 241018A: SVOM/C-GFT optical observations
  8. EP241021a: NOT likely optical counterpart
  9. GRB241017A: 1.3m DFOT optical upper limit
  10. GRB 241018A: 1.3m DFOT Optical upper limit
  11. GRB 241018A: EP-FXT afterglow detection
  12. EP241021a: GOTO optical upper limits
  13. GRB 241018A/sb24101802: Mephisto optical upper limit
  14. GRB 241017A/sb24101702: Mephisto optical upper limit
  15. GRB 241018A: BOOTES-4/MET optical upper limit
  16. GRB 241018A: Mondy optical upper limit
  17. GRB 241018A: GROWTH-India telescope optical upper limit
  18. GRB241018A: XingLong Optical Upper Limit
  19. GRB 241018A: Swift-XRT observations
  20. GRB 241018A: REM optical/NIR upper limits
  21. GRB 241018A: NOT optical observations
  22. GRB 241017A: SVOM/VT follow-up and optical upper limit
  23. GRB 241018A: SVOM/VT follow-up and optical candidate
  24. GRB 241018A: LCO/0.4m optical upper limits
  25. GRB 241006A: VIRT Optical Upper Limit
  26. GRB 240727A: VIRT Optical Upper Limit
  27. GRB241017a: Liverpool Telescope observations of XRT uncatalogued sources
  28. GRB 241017A: GROWTH-India Telescope optical upper limit
  29. GRB 240916A: radio detection with the VLA
  30. GRB 241009A: LCO optical upper limits
  31. GRB 241009A: GRANDMA optical upper limits
  32. GRB 241010A: JinShan optical observations and potential host galaxy
  33. GRB 241010A: J-band observations with WINTER
  34. GRB 241010A: LCO optical observations
  35. GRB 241010A: Swift detection of a burst with an optical counterpart
  36. GRB 241002B: Swift-XRT afterglow detection
  37. GRB 241002A: NOT optical upper limits
  38. IceCube-241006A: No candidates from the Zwicky Transient Facility
  39. GRB 241006A: GRANDMA optical upper limits
  40. EP240930a / GRB 240930B: CrAO ZTSH optical upper limit
  41. GRB 241002B: PRIME near-infrared detection in 3rd epoch
  42. GRB 240910A: LBT optical observations
  43. GRB 241006A: Swift/UVOT Upper Limits
  44. GRB 241006A: SVOM/VT follow-up and optical upper limit
  45. GRB 241001A: Swift-XRT afterglow detection
  46. GRB 240930B: SVOM/C-GFT optical upper limit
  47. GRB 241002B: PRIME near-infrared detection in 2nd epoch
  48. GRB 241002B: Swift-XRT observations
  49. GRB 241002C: SVOM/C-GFT optical upper limit
  50. GRB 241002B: PRIME near-infrared detection
  51. GRB 241001A : SVOM/VT optical detection
  52. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  53. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  54. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  55. GRB 241002C : MITSuME Akeno optical upper limits
  56. NuEm-240926A: Upper limits from a search for coincident neutrino events in IceCube
  57. GRB241001A: REM optical/NIR upper limits
  58. GRB 241002A: Swift/UVOT Upper Limits
  59. EP240930a: Liverpool Telescope observations
  60. GRB 241002A: LCOGT Optical Upper Limits
  61. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  62. GRB 241001A: Swift/UVOT Detection
  63. GRB 241001A: VLT/X-shooter redshift
  64. GRB 241002B: GOTO optical counterpart candidate
  65. EP trigger ID 01709064214: GOTO confirms detection as a flare star
  66. GRB 241001A: Swift-XRT observations
  67. GRB241001A: optical afterglow candidate
  68. GRB 241002A: 1.5m OSN optical upper limit
  69. GRB 241001A: BOOTES-6/DPRT optical upper limit
  70. EP240930a : KAIT optical upper limit
  71. EP240930a: GOTO optical upper limits
  72. GRB 240929A : Leavitt Observatory optical upper limit
  73. GRB 240825A: LBT optical observations
  74. NuEm-240926A / IC240926A: BZQJ0955+4532 ~0.6m optical decay and rebrightening detection by MASTER
  75. GRB 240529A: FRAM-ORM early optical afterglow observations reveal plateau and rebrightening
  76. LIGO/Virgo S240919bn: GOTO optical upper limits
  77. EP240913A/GRB 240913C: AbAO optical upper limit
  78. EP240919a / GRB 240919A: Mondy optical upper limit
  79. EP240913a/GRB 240913C: 1.6m Mephisto observations
  80. EP240918a: SVOM/VT upper limit
  81. EP240919a / GRB 240919A: REM optical and NIR upper limits
  82. EP240919a / GRB 240919A: KAIT optical upper limit
  83. EP240918b and EP240918c: Optical upper limits with Kinder observations
  84. EP240919a: Optical upper limit with Kinder observations
  85. GRB 240910A: radio detection with the VLA
  86. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  87. EP240919a: NOT and Gemini optical observations
  88. EP240919a: GOTO optical upper limits
  89. EP240919a: JinShan optical upper limits
  90. EP240918a: JinShan optical upper limits
  91. EP240918a: YAHPT Optical Upper Limit
  92. EP240918a: Optical upper limits with Kinder observations
  93. EP240918a: GMG Optical Upper Limit
  94. GRB 240916A: NOT optical observation
  95. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
  96. GRB 240916A: Fermi GBM Observation
  97. GRB 240916A (AT 2024vlp / GOTO24fzn): VLT/X-shooter redshift
  98. GRB 240916A: Swift-XRT afterglow detection
  99. GRB 240916A: JinShan optical decay in one of the two GOTO candidates
  100. GRB 240916A: GOTO identification of two new optical sources within the GBM localisation region

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