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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

16242 results found.

  1. GRB 240825A: SVOM/VT optical detection
  2. GRB 240825A: further SAO RAS optical observations
  3. GRB 240825A: iTelescope optical observations
  4. GRB 240828B: Swift-XRT afterglow detection
  5. Fermi GRB 240828A: Bassano Bresciano Observatory upper limit
  6. GRB 240821A: PRIME near-infrared observations
  7. GRB 240828B : Detection of a possible very soft X-ray transient by SVOM/ECLAIRs
  8. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  9. GRB 240825A: SAO RAS optical observations
  10. GRB 240824A: GIT optical upper limit
  11. GRB 240825A: NUTTelA-TAO / BSTI Optical Limits
  12. GRB 240825A: GMG Continued Optical Observation on the Second Night
  13. GRB 240825A: PRIME near-infrared detection
  14. GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
  15. GRB 240825A: AstroSat CZTI detection of the long bright burst
  16. SGR 1E 1841-045 / Kes 73: SVOM/GRM observation
  17. GRB 240825A: Swift/UVOT Detection
  18. GRB 240825A: REM detection of the optical/NIR afterglow
  19. GRB 240825A: Montarrenti Observatory optical observations
  20. GRB 240825A: Enhanced Swift-XRT position
  21. GRB 240825A: LCO optical observations
  22. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  23. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  24. GRB 240824B: NOT optical upper limit
  25. GRB 240825A: GMG Optical Observation
  26. GRB 240825A: 1.6m Mephisto multi-band detection
  27. GRB 240825A: AKO Optical Afterglow Detection
  28. GRB 240825A: Skynet Optical Afterglow observations
  29. GRB 240825A: Nanshan/HMT optical afterglow observations
  30. GRB 240825A: Swift detection of a burst with a bright optical counterpart
  31. GRB 240824A: SVOM/C-GFT optical upper limit
  32. GRB 240824B: Swift-XRT afterglow detection
  33. GRB 240824A: Swift/UVOT Upper Limits
  34. GRB 240821A: Swift/UVOT observations of the XRT sources.
  35. GRB240824A: GRANDMA/TAROT-TCA Upper Limit
  36. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  37. GRB 240824A: Skynet Optical Afterglow Discovery
  38. GRB 240824A: Swift detection of a burst
  39. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  40. GRB 240821A: Colibri Optical Upper Limit
  41. EP240820a: PRIME J-band Observations
  42. GRB 240822A: AstroSat CZTI detection of a short burst
  43. GRB 240821A: REM optical/NIR upper limits
  44. GRB 240821A: LCO optical observations
  45. GRB 240821A: JinShan optical upper limits
  46. GRB 240809A: Mondy and AbAO Optical Observations
  47. GRB 240821A: GMG Optical Upper Limit
  48. GRB 240821A: EP-FXT follow-up observation and afterglow candidates
  49. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  50. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  51. EP240820a: TRT optical upper limit
  52. EP240820a: EP detection of a fast X-ray transient
  53. EP240816a: PRIME upper limits
  54. GRB 240819A : an X-ray transient detected by SVOM/ECLAIRs
  55. GRB 240819A: TRT optical upper limits on the Swift/XRT and EP/FXT sources
  56. GRB 240819A: X-ray follow-up observation with EP-FXT
  57. EP240816b: Liverpool Telescope optical follow-up observations
  58. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  59. EP240816a: EP detection of a fast X-ray transient and follow-up observation
  60. EP240816b: TRT optical upper limit
  61. EP240816b: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  62. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  63. LIGO/Virgo/KAGRA S240813c: Identification of a GW compact binary merger candidate
  64. EP240807a: PRIME H-band upper limits
  65. GRB 240812B: AstroSat CZTI detection of a long burst
  66. GRB 240811A: Bassano Bresciano Observatory upper limit
  67. GRB 240811A: Swift-XRT refined Analysis
  68. GRB 240811A: Swift/UVOT Upper Limits
  69. EP240801a: Assy-Turgen optical observations
  70. GRB 240811A: LCOGT Optical Upper Limit
  71. GRB 240811A: Enhanced Swift-XRT position
  72. GRB 240811A: Upper limits with Mephisto
  73. GRB 240811A: Swift detection of a burst
  74. GRB 240809A: REM detection of the optical afterglow
  75. GRB 240809A: Bassano Bresciano Observatory optical observations
  76. GRB 240809A: GIT afterglow observations
  77. GRB 240809A: Swift/UVOT Detection
  78. GRB 240809A: Swift-XRT refined Analysis
  79. IPN triangulation of GRB 240807A / EP 240807a
  80. X-ray Transient EP240807a: PRIME near-infrared upper limits
  81. GRB 240809A: JinShan optical observations
  82. GRB 240809A: Enhanced Swift-XRT position
  83. GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
  84. GRB 240809A: Swift detection of a burst with a bright optical counterpart
  85. EP-WXT trigger 01709018832: SVOM/C-GFT observations of the star flare
  86. GRB 240805A: ATCA Radio Upper Limits
  87. EP240807a/GRB 240807A: EP-FXT detection of the X-ray emission
  88. EP240806A: Liverpool Telescope optical follow-up observations
  89. The EP-WXT trigger 01709018832 on August 7th is likely a flaring star
  90. EP240807a: EP-WXT detection of a fast X-ray transient
  91. EP240806a: Gemini North-GMOS spectroscopic redshift of z = 2.818
  92. GRB 240805B: GIT optical upper limit
  93. EP240806a: LCOGT optical counterpart detection
  94. GRB 240805B Bassano Bresciano Observatory upper limit
  95. GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
  96. EP240806a: EP-FXT detection of the X-ray emission
  97. EP 240806A: LCO optical observations
  98. EP240806a: EP-WXT detection of a fast X-ray transient
  99. GRB 240805B: Optical detection with 1.6m Mephisto
  100. GRB 240805B: NUTTelA-TAO / BSTI Optical Limits

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