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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"

7445 results found.

  1. LIGO/Virgo G298048: Zadko observations of the OT candidate SSS17a/DLT17ck
  2. LIGO/Virgo G298048: NuSTAR limits on X-ray emission
  3. LIGO/Virgo G298048: optical observations with BOOTES-5 at San Pedro Mártir
  4. LIGO/Virgo G298048: On the kick velocity and age of the binary Neutron Stars Progenitor
  5. LIGO/Virgo G298048: optical observations of CHILESCOPE observatory
  6. LIGO/Virgo G298048: VLA observation at 6 GHz
  7. LIGO/Virgo G298048: Continued VLA observations
  8. LIGO/Virgo G298389: INTEGRAL search for a prompt gamma-ray counterpart
  9. LIGO/VIRGO G298048: SALT optical spectra of the candidate optical/NIR counterpart of the gravitational wave G298048 in NGC4993.
  10. LIGO/Virgo G298048: GROND observations of candidate optical counterpart
  11. LIGO/Virgo G298389: Fermi GBM Upper Limits
  12. LIGO/Virgo G298048: Continued observation for DLT17ck
  13. LIGO/Virgo G298389: IceCube neutrino observations
  14. LIGO/Virgo G298389 ANTARES search
  15. LIGO/Virgo G298389: Identification of a GW Burst Candidate
  16. LIGO/Virgo G298048: KMTNet and other optical follow-up observations
  17. LIGO/Virgo G298048: further REM optical/NIR observations of candidate in NGC 4993
  18. LIGO/Virgo G298048: VLT linear polarimetry
  19. LIGO/Virgo G298048: HSC observations of the OT candidate of G298048
  20. LIGO/Virgo G298048: GROND photometry of candidate optical counterpart reveals brightening in the NIR
  21. LIGO/VIRGO G298048: ePESSTO optical spectra of the candidate optical/NIR counterpart of the gravitational wave G298048 in NGC4993.
  22. LIGO/VIRGO G298048: Expansion Velocity of SSS17a Consistent With Relativistic Merger Ejecta
  23. LIGO/Virgo G298048: optical spectral energy distribution of SSS17a
  24. LIGO/Virgo G298048: prior photometry from VISTA Hemisphere Survey
  25. LIGO/Virgo G298048: Continued Swift UV and X-ray Monitoring of SSS17a
  26. LIGO/Virgo G298048: Archival VLA observations
  27. LIGO/Virgo G298048: UPDATE on IceCube neutrino candidates --- no coincidence with newest GW skymap
  28. LIGO/Virgo G298048: Moderate dimming or no brightening of the optical counterpart candidate?
  29. LIGO/Virgo G298048: Brightening of Possible Counterpart
  30. LIGO/Virgo G298048: SkyMapper uvgri photometry of the candidate in NGC 4933
  31. LIGO/Virgo G298048: ATCA detection of a radio source coincident with NGC 4993
  32. LIGO/Virgo G298048: TZAC TAROT Reunion (TRE) observations
  33. LIGO/Virgo G298048: REM optical/NIR observations
  34. LIGO/Virgo G298048, Fermi GBM trigger 524666471/170817.529: MAXI/GSC observations
  35. LIGO/Virgo G298048: Gemini-South Near-Infrared Photometry of the Optical Transient Candidate
  36. LIGO/Virgo G298048: Subaru HSC follow-up observations
  37. LIGO/Virgo G298048: VLA Refined Analysis
  38. LIGO/Virgo G298048: VLA Detection
  39. LIGO/Virgo G298048: VISTA/VIRCAM detection of candidate counterpart
  40. LIGO/Virgo G298048: Optical Candidate Shows No Evidence for Previous Activity in Archival SkyMapper Transient Survey Data
  41. LIGO/Virgo G298048: Las Cumbres Observatory Detection of The Possible Optical Counterpart in NGC 4993
  42. LIGO/Virgo G298048: ATCA observations of candidate host galaxies
  43. LIGO/Virgo G298048 : Fermi-LAT search for a high-energy gamma-ray counterpart
  44. LIGO/Virgo G298048: Optical Candidate Shows No Evidence for Previous Activity in Archival ASAS-SN Data
  45. LIGO/Virgo G298048: REM optical/NIR observations of candidate in NGC 4993
  46. LIGO/Virgo G298048: DLT40 optical candidate
  47. LIGO/Virgo G298048: DECam optical candidate
  48. LIGO/Virgo G297595: Pierre Auger Observatory neutrino follow-up
  49. LIGO/Virgo G298048 ANTARES search
  50. LIGO/Virgo G298048: Potential host galaxies from the GLADE catalog
  51. LIGO/Virgo G298048: Further analysis of a binary neutron star candidate with updated sky localization
  52. LIGO/Virgo G298048: COINCIDENT IceCube neutrino candidate with Fermi GBM trigger 524666471/170817529
  53. LIGO/Virgo G298048: correction to the luminosity distance reported in GCN 21509
  54. LIGO/Virgo G298048: Identification of a binary neutron star candidate coincident with Fermi GBM trigger 524666471/170817529
  55. LIGO/Virgo G298048: FOUND COINCIDENT IceCube neutrino observation
  56. LIGO/Virgo G298048: INTEGRAL detection of a prompt gamma-ray counterpart
  57. LIGO/Virgo G298048: Fermi GBM trigger 524666471/170817529: LIGO/Virgo Identification of a possible gravitational-wave counterpart
  58. LIGO/Virgo G296853 TZAC TAROT observations
  59. LIGO/Virgo G296853: Pierre Auger Observatory neutrino follow-up
  60. LIGO/Virgo G297595: REM optical/NIR observations
  61. LIGO/Virgo G297595: Updated localization from LIGO and Virgo data
  62. LIGO/Virgo G297595: Correction to luminosity distance stated in GCN 21474
  63. LIGO/Virgo G297595: Fermi GBM Observations
  64. LIGO/Virgo G297595 : Fermi-LAT search for high-energy gamma-ray counterpart
  65. LIGO/Virgo G297595 ANTARES search
  66. LIGO/Virgo G297595: INTEGRAL search for a prompt gamma-ray counterpart
  67. LIGO/Virgo G297595: IceCube neutrino observations
  68. LIGO/Virgo G297595: Identification of a GW Binary Merger Candidate
  69. GRB 170813A: Swift detection of a burst
  70. LIGO/Virgo G296853: BOOTES-1 and GTC optical observations
  71. GRB 170810A: Swift detection of a burst with a bright optical counterpart
  72. LIGO/Virgo G296853: HAWC follow-up
  73. LIGO/Virgo G296853: Fermi-LAT search for high-energy gamma-ray counterpart
  74. LIGO/Virgo G296853: Fermi GBM Observations
  75. LIGO/Virgo G296853 ANTARES search
  76. LIGO/Virgo G296853: IceCube neutrino observations
  77. LIGO/Virgo G296853: Identification of a GW Binary Merger Candidate
  78. GRB 170804A: Swift detection of a burst with optical counterpart
  79. Swift Trigger 766161 is not a GRB
  80. GRB 170803A: Swift detection of a burst with an optical counterpart
  81. GRB 170728B: position of the TNG optical counterpart
  82. GRB 170728B: TNG optical afterglow candidate
  83. GRB 170728B: Swift detection of a short burst
  84. Swift triggers on a new galactic source: Swift J181723.1-164300
  85. GRB 170728A: Swift detection of a burst
  86. Trigger 763539 from Swift is probably not astrophysical
  87. Correction to GCN Circular 21351: GRB 170714A: Swift/UVOT Observations
  88. GRB 170714A: Swift/UVOT Observations
  89. GRB 170714A: TNG NIR observations
  90. GRB 170714A: z-band afterglow candidate for OSIRIS/GTC
  91. GRB 170714A: Swift detection of a burst
  92. GRB 170711A: Swift detection of a burst
  93. GRB 170710B: Swift ToO observations
  94. GRB 170710A: Gemini-S candidate counterpart
  95. GRB 170710A: Swift detection of a burst
  96. GRB 170705A: Swift detection of a burst with an optical counterpart
  97. LIGO/Virgo G274296: Updated localization from LIGO data
  98. GRB 170629A: Swift detection of a burst
  99. LIGO/Virgo G270580: Candidate retracted due to H1 data quality
  100. GRB 170626A: TNG optical observations

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