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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"

24663 results found.

  1. GRB 241026A: Las Cumbres optical detection
  2. GRB 241025A: Mondy optical observations
  3. EP241021a: SOAR observations of the optical counterpart
  4. EP241021a: further SAO RAS optical observations
  5. GRB 241026A: Swift-XRT refined Analysis
  6. EP 241026b: LBT optical observations
  7. GRB 241026A: Enhanced Swift-XRT position
  8. EP241026b: EP detection of a fast X-ray transient
  9. GRB 241026A: COLIBRÍ Detection of the Optical Counterpart
  10. GRB 241026A: SAO RAS observations of possible optical afterglow
  11. GRB 241026A: Swift detection of a burst
  12. GRB241025A: 1.3m DFOT optical afterglow detection
  13. EP241021a: optical follow-up observations with Xinglong Observatory
  14. GRB 241025A: GROWTH-India Telescope optical observations
  15. GRB 241025A: COLIBRÍ Detection of the Afterglow
  16. GRB 241025A: Swift-XRT refined Analysis
  17. GRB 241025C: Fermi GBM Detection
  18. GRB 241025A: Fermi GBM Observation
  19. IPN triangulation of GRB 241022A (short/hard)
  20. LIGO/Virgo/KAGRA S241009l: Upper limits from Swift/BAT-GUANO
  21. EP 241021a: Swift-XRT observations
  22. GRB 241025A : SVOM/VT optical afterglow observations
  23. EP241021a: Liverpool Telescope optical follow-up observations
  24. GRB 241025A: Enhanced Swift-XRT position
  25. GRB 241025A: DDOTI Afterglow detection
  26. GRB 241025A: TRT optical afterglow observation
  27. GRB 241025A: Swift detection of a burst with an optical counterpart
  28. EP241021a: GTC OSIRIS+ spectroscopy of the optical counterpart
  29. GRB 241001A: ATCA radio observations
  30. GRB 241010A: VIRT Optical Upper Limit
  31. EP241021a: SAO RAS optical observations
  32. EP241021a: KAIT optical observations
  33. EP241021a: 1.3m DFOT Optical observations
  34. EP241021a: GSP detects optical candidate counterpart
  35. EP241021a: Optical upper limits with Kinder observations
  36. EP241021a: TRT optical observations
  37. GRB 241018A: SVOM/C-GFT optical observations
  38. EP241021a: NOT likely optical counterpart
  39. EP EP241021a: Global MASTER-Net observations report
  40. GRB241017A: 1.3m DFOT optical upper limit
  41. GRB 241018A: 1.3m DFOT Optical upper limit
  42. EP241021a: GOTO optical upper limits
  43. EP241021a: EP detection of a fast X-ray transient
  44. IceCube-Cascade 241019A: Upper limits from a search for additional neutrino events in IceCube
  45. GRB 241018A/sb24101802: Mephisto optical upper limit
  46. GRB 241017A/sb24101702: Mephisto optical upper limit
  47. GRB 241018A: Mondy optical upper limit
  48. GRB 241018A: SVOM/VT further analysis and counterpart confirmed
  49. GRB 241018A: GROWTH-India telescope optical upper limit
  50. GRB241018A: XingLong Optical Upper Limit
  51. GRB 241018A: Swift-XRT observations
  52. GRB 241018A: REM optical/NIR upper limits
  53. GRB 241018A: NOT optical observations
  54. GRB 241018A: SVOM/VT follow-up and optical candidate
  55. GRB 241018A: LCO/0.4m optical upper limits
  56. GRB 241006A: VIRT Optical Upper Limit
  57. GRB 240727A: VIRT Optical Upper Limit
  58. GRB 241018A: X-ray afterglow candidate observed by MXT
  59. GRB 241017A: Swift-XRT observations
  60. GRB241017a: Liverpool Telescope observations of XRT uncatalogued sources
  61. GRB 241001A: EP-FXT afterglow detection
  62. GRB 241017A: GROWTH-India Telescope optical upper limit
  63. GRB241017A: TOO Observations by SVOM/MXT
  64. GRB 241016B: Swift/BAT-GUANO localization skymap of a short burst
  65. GRB 241017A: J-band upper limit from WINTER
  66. GRB 241016B: SVOM/GRM observation
  67. GRB 241017A : Detection of a weak and soft long duration GRB by SVOM/ECLAIRs
  68. GRB 241010A: Swift-BAT refined analysis
  69. GRB 241013B: Fermi GBM Observation
  70. GRB 241013B: Swift/BAT-GUANO localization skymap of a burst
  71. GRB 241013A: Fermi GBM Observation
  72. GRB 240916A: radio detection with the VLA
  73. GRB241013A: REM observations
  74. GRB 241009A: LCO optical upper limits
  75. Integral GRB241013.04: Global MASTER-Net observations report
  76. LIGO/Virgo/KAGRA S241009em: Updated Sky localization
  77. LIGO/Virgo/KAGRA S241011k: Updated Sky localization
  78. LIGO/Virgo/KAGRA S241011k: NED Galaxies in the Localization Volume
  79. LIGO/Virgo/KAGRA S241011k: Identification of a GW compact binary merger candidate
  80. GRB 241009A: GRANDMA optical upper limits
  81. GRB 241009A: Swift-XRT afterglow detection
  82. GRB 241010A: JinShan optical observations and potential host galaxy
  83. GRB 241010A: Swift-XRT refined Analysis
  84. LIGO/Virgo/KAGRA S241007bw: Updated Sky localization
  85. Fermi trigger No 750211959: Global MASTER-Net observations report
  86. Fermi trigger No 750291012: Global MASTER-Net observations report
  87. GRB 241010A: J-band observations with WINTER
  88. LIGO/Virgo/KAGRA S241009an: Updated Sky localization
  89. IceCube-241006A: Upper limits from a search for additional neutrino events in IceCube
  90. GRB 241010A: Enhanced Swift-XRT position
  91. GRB 241010A: LCO optical observations
  92. GRB 241010A: Swift detection of a burst with an optical counterpart
  93. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  94. GRB 241006A: Swift-BAT refined analysis
  95. LIGO/Virgo/KAGRA S241009l: Updated Sky localization
  96. LIGO/Virgo/KAGRA S241009em: Identification of a GW compact binary merger candidate
  97. GRB 241008A: Fermi GBM Observation
  98. GRB 241002B: Swift-XRT afterglow detection
  99. LIGO/Virgo/KAGRA S241009an: Identification of a GW compact binary merger candidate
  100. GRB 241002A: NOT optical upper limits

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