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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"

24658 results found.

  1. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  2. EP241103a: GSP optical upper limit
  3. EP241103A: LCO optical observations
  4. EP241103a: an X-ray transient detected by Einstein Probe
  5. LIGO/Virgo/KAGRA S241101ee: Updated Sky localization
  6. S241102cy: Identification of a GW compact binary merger candidate
  7. LIGO/Virgo/KAGRA S241102br: NED Galaxies in the Localization Volume
  8. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  9. Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A
  10. GRB241030A: OHP/T193 optical observations
  11. GRB 241101A: FRAM-ORM optical limit
  12. LIGO/Virgo/KAGRA S241101ee: Identification of a GW compact binary merger candidate
  13. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  14. EP241021a: Upper limit from Konus-Wind observations
  15. GRB 241101A: Swift-BAT refined analysis
  16. GRB 241030A: further SAO RAS optical observations
  17. GRB 241030A: Optical Observations via Virtual Telescope Project
  18. EP241021a: Liverpool Telescope optical follow-up observations
  19. GRB 241030B: Swift-XRT refined Analysis
  20. GRB 241026A: SAO RAS optical observations
  21. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  22. GRB 241101A: Swift detection of a burst
  23. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  24. EP241021a: OHP/T193 optical observations
  25. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  26. GRB 241030B: Montarrenti Observatory optical upper limit
  27. EP241026b: Liverpool Telescope optical follow-up
  28. GRB 241030A: SAO RAS optical observations
  29. GRB 241030A: Fermi GBM Observation
  30. EP241021a: AMI-LA radio detection
  31. GRB 241030B : GIT optical upper limits
  32. GRB 241030B: LCOGT Optical Upper Limits
  33. GRB 241030B: Swift-BAT refined analysis
  34. GRB 241030A: Swift-BAT refined analysis
  35. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  36. GRB 241030B: Swift/UVOT Detection
  37. GRB 241029A: LCO optical detection
  38. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  39. GRB 241030B : MITSuME Akeno optical upper limits
  40. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  41. GRB 241030B: SVOM/VT optical afterglow observations
  42. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  43. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  44. GRB241030B: Fermi GBM Observation
  45. GRB 241030B: BTA observations
  46. GRB 241029A: SVOM/VT optical afterglow observations
  47. GRB 241030A: detection of the bright optical counterpart in ATLAS forced photometry
  48. GRB 241030B: Enhanced Swift-XRT position
  49. GRB241030B: GRANDMA/TAROT Upper Limit
  50. GRB 241030A: Swift-XRT refined Analysis
  51. GRB 241030B: SAO RAS optical observations
  52. GRB 241030B: AKO Optical Afterglow Detection
  53. GRB 241030B: Nanshan/HMT optical afterglow detection
  54. GRB 241030B: Swift detection of a burst
  55. GRB 240912A: radio detection with the VLA
  56. GRB 241030A: AKO Optical Afterglow Detection
  57. GRB 241030A: Swift/UVOT Detection
  58. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  59. GRB 241026A: Swift-BAT refined analysis
  60. GRB 241030A: SVOM/C-GFT optical observations
  61. GRB 241026A: LBT optical observations
  62. EP241021a: Optical rebrightening observations with Mephisto
  63. GRB 241030A: Multiband optical detection with Mephisto
  64. GRB 241030A: SVOM/VT optical afterglow observations
  65. GRB 241030A : MITSuME Akeno optical afterglow detection
  66. GRB 241030A: Enhanced Swift-XRT position
  67. GRB 241029A: GROWTH-India Telescope optical follow up
  68. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  69. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  70. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  71. GRB 241029A: SAO RAS optical observations
  72. GRB 241026A: SAO RAS optical observations
  73. EP241021a: SAO RAS observations of rebrightening
  74. GRB 241029A: GTC/OSIRIS+ spectroscopic redshift z=1.072
  75. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  76. GRB 241026A: Swift/UVOT Upper Limits
  77. GRB 241029A: Swift-XRT observations
  78. GRB 241029A: Fermi GBM Observation
  79. GRB 241029A: AKO Optical Afterglow Detection
  80. EP241021a: continued SOAR observations confirm optical rebrightening
  81. GRB 241029A: Xinglong-2.16m optical afterglow confirmation
  82. GRB 241029A: Mephisto observations
  83. EP 241026b: LBT possible optical counterpart (brightening source)
  84. GRB 241029A: TRT optical afterglow candidate detection
  85. GRB 241026A: TNOT optical counterpart detection
  86. GRB 241025A (EP241025a): Optical afterglow observations with the Tsinghua-Nanshan Optical Telescope
  87. GRB 241025A: further SAO RAS optical observations
  88. GRB 241026A: BTA and Zeiss-1000 optical observations
  89. GRB 241026A: SVOM/GRM observation
  90. EP241026B: GROWTH-India Telescope optical upper limit
  91. GRB 241025A: Swift/UVOT Detection
  92. GRB 241026A: GROWTH-India Telescope optical observations
  93. GRB 241026A Fermi GBM Analysis
  94. GRB 241026A: J-band observations with WINTER
  95. GRB 241025A: SAO RAS optical observations
  96. GRB 241026A: Las Cumbres optical detection
  97. GRB 241025A: Mondy optical observations
  98. EP241021a: SOAR observations of the optical counterpart
  99. EP241021a: further SAO RAS optical observations
  100. GRB 241026A: Swift-XRT refined Analysis

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