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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"

24705 results found.

  1. LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
  2. GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart
  3. LIGO/Virgo/KAGRA S241109p: Updated Sky localization and Source Classification
  4. LIGO/Virgo/KAGRA S241109bn: Identification of a GW compact binary merger candidate
  5. EP241109a: confirmation of a stellar flare by BOOTES-7
  6. GRB 241108A: Swift-XRT observations
  7. LIGO/Virgo/KAGRA S241109p: Identification of a GW compact binary merger candidate
  8. EP241107a: KAIT optical observations
  9. GRB 241030A: TESS observations
  10. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  11. EP241107a: Kinder optical follow-up observations
  12. GRB 241025A: radio detection with the VLA
  13. EP241107a: AKO Optical Afterglow Follow-Up Observations
  14. EP241107a: GSP detects optical counterpart
  15. GRB 241105A: SVOM/GRM observation
  16. EP241107a: OHP/T193 photometric and spectroscopic observations
  17. GRB 241105a: PRIME near-infrared upper limits
  18. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  19. EP241107a: GIT optical observations
  20. EP241107a: SVOM/C-GFT optical observations
  21. EP241107a: AKO Optical Afterglow Detection
  22. GRB 241025A: LBT optical observations
  23. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  24. GRB 241105A: Swift/UVOT Detection
  25. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  26. LIGO/Virgo/KAGRA S241106ba: 1 counterpart neutrino candidate event from an IceCube neutrino search
  27. LIGO/Virgo/KAGRA S241102o: 1 counterpart neutrino candidate event from an IceCube neutrino search
  28. GRB 241105A: Swift-XRT afterglow detection
  29. GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.681
  30. GRB 241104A: Swift-XRT observations
  31. GRB 240511A: LCO upper limits
  32. GRB 241104A: Fermi GBM Observation
  33. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  34. GRB 241104A: SVOM/VT optical candidate
  35. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  36. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  37. EP241104a: EP detection of GRB 241104A X-ray emission
  38. GRB 241010A: host galaxy redshift z = 0.977
  39. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  40. GRB 240821A: further radio observations with the VLA
  41. EP241103a: GIT optical upper limit
  42. EP241021a: OHP/T193 further optical observations
  43. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  44. LIGO/Virgo/KAGRA S241102cy: Updated Sky localization
  45. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  46. EP241103a: Swift XRT detection and improved X-ray position
  47. EP241021a: continued SOAR observations
  48. EP241101a: Optical upper limits with Kinder observations
  49. EP241101a: OHP/T193 optical observations
  50. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  51. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  52. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  53. EP241103a: GSP optical upper limit
  54. EP241103A: LCO optical observations
  55. EP241103a: an X-ray transient detected by Einstein Probe
  56. LIGO/Virgo/KAGRA S241101ee: Updated Sky localization
  57. S241102cy: Identification of a GW compact binary merger candidate
  58. LIGO/Virgo/KAGRA S241102br: NED Galaxies in the Localization Volume
  59. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  60. Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A
  61. GRB241030A: OHP/T193 optical observations
  62. GRB 241101A: FRAM-ORM optical limit
  63. LIGO/Virgo/KAGRA S241101ee: Identification of a GW compact binary merger candidate
  64. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  65. EP241021a: Upper limit from Konus-Wind observations
  66. GRB 241101A: Swift-BAT refined analysis
  67. GRB 241030A: further SAO RAS optical observations
  68. GRB 241030A: Optical Observations via Virtual Telescope Project
  69. EP241021a: Liverpool Telescope optical follow-up observations
  70. GRB 241030B: Swift-XRT refined Analysis
  71. GRB 241026A: SAO RAS optical observations
  72. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  73. GRB 241101A: Swift detection of a burst
  74. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  75. EP241021a: OHP/T193 optical observations
  76. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  77. GRB 241030B: Montarrenti Observatory optical upper limit
  78. EP241026b: Liverpool Telescope optical follow-up
  79. GRB 241030A: SAO RAS optical observations
  80. GRB 241030A: Fermi GBM Observation
  81. EP241021a: AMI-LA radio detection
  82. GRB 241030B : GIT optical upper limits
  83. GRB 241030B: LCOGT Optical Upper Limits
  84. GRB 241030B: Swift-BAT refined analysis
  85. GRB 241030A: Swift-BAT refined analysis
  86. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  87. GRB 241030B: Swift/UVOT Detection
  88. GRB 241029A: LCO optical detection
  89. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  90. GRB 241030B : MITSuME Akeno optical upper limits
  91. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  92. GRB 241030B: SVOM/VT optical afterglow observations
  93. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  94. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  95. GRB241030B: Fermi GBM Observation
  96. GRB 241030B: BTA observations
  97. GRB 241029A: SVOM/VT optical afterglow observations
  98. GRB 241030A: detection of the bright optical counterpart in ATLAS forced photometry
  99. GRB 241030B: Enhanced Swift-XRT position
  100. GRB241030B: GRANDMA/TAROT Upper Limit

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