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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').
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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"

32538 results found.

  1. GRB 241217A/EP241217b: REM optical/NIR upper limits
  2. EP241217a: REM optical/NIR upper limits
  3. GRB 241218a: Liverpool Telescope optical follow-up
  4. GRB 241217a: Liverpool Telescope optical follow-up
  5. EP241217a: Liverpool Telescope optical follow-up
  6. EP241217a: NOT optical observations
  7. EP241217a: GROWTH-India Telescope optical observations
  8. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  9. EP241119a: 7DT Optical upper limits
  10. EP241217b: Global MASTER-Net observations report
  11. GRB 241209A: ATCA radio follow-up observations
  12. EP241217a: Xinglong optical follow-up observations
  13. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  14. GRB 241218A: LCOGT Optical Upper Limit
  15. EP241217a: Global MASTER-Net observations report
  16. GRB 241217A: GMG Optical Upper Limit
  17. GRB 241217A : SVOM/VT optical afterglow detection
  18. GRB 241217A: LCO optical upper limit
  19. GRB 241217A: GRANDMA/TAROT optical upperlimits
  20. EP241217a: Swift-XRT Detection
  21. EP241217A: Non-detection from Fermi-GBM Observations
  22. EP241217a: Gemini-North spectroscopic redshift z = 4.59
  23. EP241217a: Kinder optical follow-up observations
  24. GRB 241214A: GRBAlpha detection
  25. GRB 241213A (EP241213a): GRBAlpha detection
  26. GRB 241209D: GRBAlpha detection
  27. EP241217A: LCO optical observations
  28. EP241217a: Gemini-North detection of the likely optical counterpart
  29. EP241107a: VLA Radio Observation
  30. GRB 241213A: Swift-BAT refined analysis
  31. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  32. Konus-Wind detection of GRB 241213A (EP 241213a)
  33. GRB 241215A: Mondy AZT-33IK optical observations
  34. GRB 241215A: Nanshan/HMT optical upper limit
  35. GRB 241215A: Montarrenti Observatory optical upper limit
  36. GRB 241215A: GROWTH-India telescope optical upper limit
  37. GRB 241209D: CALET Gamma-Ray Burst Monitor detection
  38. GRB 241209B: SVOM/VT optical continuous fading
  39. GRB 241213A: SVOM/VT optical candidate
  40. GRB 241213B: Tiled Swift observations
  41. GRB 241213A: Swift/UVOT Upper Limits
  42. GRB 241213B: CALET Gamma-Ray Burst Monitor detection
  43. GRB 241212A: Fermi GBM detection
  44. EP241208a: NOT optical upper limits
  45. GRB 241212A: Swift ToO observations
  46. GRB 241213A: LCOGT Optical Upper Limits
  47. EP 241208A : Detection of a long soft transient by SVOM/ECLAIRs
  48. EP241213a/GRB241213a: Likely joint detection and INTEGRAL/SPI-ACS counterpart
  49. GRB 241213A: REM optical/NIR upper limits
  50. GRB241212A: OHP/T193 optical observations
  51. GRB 241213A: SAO RAS optical upper limit
  52. LIGO/Virgo/KAGRA S241210fu: Updated Sky localization
  53. Swift GRB 241213A: Global MASTER-Net observations report
  54. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  55. GRB 241212A : SVOM/VT bright optical afterglow
  56. GRB 241212A: AstroSat CZTI detection
  57. GRB 241209B: GRANDMA/TRT upper limit
  58. GRB 241207A: TSHAO Zeiss-1000 optical observations
  59. GRB 241212A: SVOM detection of a bright long burst
  60. GRB 241209B: Mondy AZT-33IK and AbAO AS-32 optical observations
  61. GRB 241209A: Chandra X-ray Detection
  62. Konus-Wind detection of GRB 241209B
  63. GRB 241207A: EIRSAT-1 GMOD Detection
  64. GRB 241209A: Redshift of the likely host galaxy z = 0.784 from OSIRIS+/GTC
  65. GRB 241209B: GRBAlpha detection
  66. GRB 241206C: GRBAlpha detection
  67. LIGO/Virgo/KAGRA S241210cw: Updated Sky localization
  68. LIGO/Virgo/KAGRA S241210d: Updated Sky localization and EM Bright Classification
  69. GRB 241129A: Fermi GBM Observation
  70. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  71. GRB 241209D: REM optical/NIR upper limits
  72. Konus-Wind detection of GRB 241209D
  73. GRB 241209B: Swift-XRT afterglow detection
  74. GRB 241209C: Fermi GBM Observation
  75. LIGO/Virgo/KAGRA S241210fu: Identification of a GW compact binary merger candidate
  76. EP241208a: Optical upper limit with Kinder observations
  77. GRB 241128A: CrAO ZTSh and Mondy AZT-33IK optical observations
  78. GRB 241209D: AstroSat CZTI detection
  79. GRB 241209A: EP-FXT follow-up observations
  80. GRB 241209B: SVOM/VT afterglow detection
  81. LIGO/Virgo/KAGRA S241210cw: Identification of a GW compact binary merger candidate
  82. EP241208a: Global MASTER-Net observations report
  83. EP241208a: EP-FXT follow-up observations
  84. LIGO/Virgo/KAGRA S241210d: Identification of a GW compact binary merger candidate
  85. GRB 241207B: Fermi GBM Observation
  86. GRB 241209A: BOOTES-7 and 2.2m CAHA early optical upper limits
  87. GRB 241209D: Fermi GBM Observation
  88. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  89. GRB 241209D: COLIBRÍ detection of the afterglow
  90. GRB 241209A: COLIBRÍ Optical Upper Limit
  91. Fermi GRB 241209D: Global MASTER-Net observations report
  92. GRB 241209A: Fermi GBM Observation
  93. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  94. GRB 241209A: GRANDMA/TAROT upper limit
  95. GRB 241209B: BOOTES-5 optical upper limit
  96. Swift GRB 241209D: Global MASTER-Net observations report
  97. Fermi GRB 241209C: Global MASTER-Net observations report
  98. Fermi GRB 241209E: Global MASTER-Net observations report
  99. GRB 241209B: Swift ToO observations
  100. LIGO/Virgo/KAGRA S241102br: continued GRAWITA observations and detection of an optical transient (AT2024adip)

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