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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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').
Advanced Search

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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

16316 results found.

  1. LIGO/Virgo G299232: Liverpool Telescope observations
  2. LIGO/Virgo G299232: observations of the optical Transient Discovered by Swift/UVOT
  3. LIGO/Virgo G298048: ALMA upper limits on 98 GHz emission from SSS17a
  4. LIGO/Virgo G299232/PGWB170825.55: early MASTER observations of the Swift UVOT source position
  5. LIGO/Virgo G298048: ALMA observations
  6. LIGO/Virgo G299232: GRAWITA Asiago/Copernico Telescope observations
  7. GRB170827A: Further GROND follow-up observations
  8. LIGO/Virgo G298048: Further ATCA follow-up of SSS17a in NGC 4993
  9. LIGO/Virgo G299232: Continued observation of the transient near NGC 1343
  10. LIGO/Virgo G299232: WHT spectrum of MASTER OT J033744.97+723159.0
  11. LIGO/Virgo G299232: Optical Transient Discovery by Swift/UVOT
  12. GRB 170823A: TAROT Calern observatory optical observations
  13. GRB 170827A: Swift/UVOT Upper Limits
  14. GRB 170827A: REM optical/NIR observations
  15. LIGO/Virgo G298048: uGMRT Follow-up of SSS17a at 400 MHz and 1.4 GHz
  16. LIGO/VIRGO G298048: INAF VST-ESO PARANAL observations of NGC4993
  17. LIGO/Virgo G297595: INTEGRAL pointed follow-up observations
  18. LIGO/Virgo G298048: MASTER Global-Net early optical observations and the Possible KiloNova SSS17a in NGC 4993 photometry and merging rate
  19. LIGO/Virgo G298048: Pierre Auger Observatory neutrino follow-up
  20. LIGO/Virgo G298048: Near-infrared fading from Gemini-South
  21. LIGO/Virgo G298048: HAWC follow-up
  22. LIGO/Virgo G298936: GWFUNC/CNEOST optical observations and an optical transient
  23. LIGO/Virgo G298048: H.E.S.S. very-high energy gamma-ray follow-up
  24. LIGO/Virgo G298048: INTEGRAL pointed follow-up observations
  25. LIGO/Virgo G298048: ATCA follow-up of SSS17a in NGC 4993
  26. LIGO/Virgo G298048: Properties of NGC 4993
  27. LIGO/Virgo G298048: Continued VLA monitoring at 6 GHz
  28. GRB 170822A: RATIR Optical and NIR Observations
  29. GRB 170822A: AbAO optical upper limit
  30. LIGO/Virgo G298048: ESO/VLT optical observations
  31. GRB 170822A: MITSuME Akeno Optical Observation
  32. GRB 170822A: Swift/UVOT Upper Limits
  33. LIGO/Virgo G298048: Chandra X-ray observations
  34. LIGO/Virgo G298048: Global properties and star-formation rate of NGC 4993
  35. LIGO/Virgo G298048: observations of optical counterpart candidate with CHILESCOPE observatory
  36. GRB 170822A:BOOTES-5/JGT optical afterglow candidate
  37. LIGO/Virgo G298048: ASKAP observations of SSS17a and NGC 4993 at 1.345 GHz
  38. LIGO/Virgo G298048: Gemini-South Near-Infrared Spectroscopy
  39. LIGO/Virgo G298048: VLA observation at 15 GHz
  40. LIGO/Virgo G298048: observations of optical counterpart candidate with CHILESCOPE observatory
  41. LIGO/Virgo G298048: Pan-STARRS izy photometry of SSS17a/DLT17ck
  42. LIGO/Virgo G298048: Continued monitoring of the optical counterpart candidate
  43. LIGO/Virgo G298048: Zadko observations of the OT candidate SSS17a/DLT17ck
  44. LIGO/Virgo G298048: NuSTAR limits on X-ray emission
  45. LIGO/Virgo G298048: ASKAP follow up
  46. LIGO/Virgo G298048: optical observations with BOOTES-5 at San Pedro Mártir
  47. LIGO/Virgo G298048: TOROS optical counterpart search (continuation)
  48. LIGO/Virgo G298048: TOROS optical counterpart search
  49. LIGO/Virgo G298048: optical observations of CHILESCOPE observatory
  50. LIGO/Virgo G298048: Pan-STARRS izy photometry monitoring of SSS17a/DLT17ck
  51. LIGO/Virgo G298048: VLA observation at 6 GHz
  52. LIGO/Virgo G298048: Continued VLA observations
  53. LIGO/Virgo G298048: Possible X-ray detection with Swift
  54. LIGO/VIRGO G298048: SALT optical spectra of the candidate optical/NIR counterpart of the gravitational wave G298048 in NGC4993.
  55. LIGO/Virgo G298048: GROND observations of candidate optical counterpart
  56. LIGO/Virgo G298048: Continued observation for DLT17ck
  57. LIGO/Virgo G298048: KMTNet and other optical follow-up observations
  58. LIGO/Virgo G298048: further REM optical/NIR observations of candidate in NGC 4993
  59. LIGO/Virgo G298048: VLT linear polarimetry
  60. LIGO/Virgo G298048: NOT near-infrared observations of SSS17a
  61. LIGO/Virgo G298048: Further Pan-STARRS izy photometry confirms rapid fading of SSS17a/DLT17ck in i and z bands
  62. LIGO/Virgo G298048: Further VLA Observations
  63. LIGO/Virgo G298048: VLBA observations of the possible counterpart SSS17a in NGC 4993
  64. LIGO/Virgo G298048: HSC observations of the OT candidate of G298048
  65. LIGO/Virgo G298048: Possible features in the spectrum of GW counterpart SSS17a
  66. LIGO/Virgo G298048: GROND photometry of candidate optical counterpart reveals brightening in the NIR
  67. LIGO/VIRGO G298048: ePESSTO optical spectra of the candidate optical/NIR counterpart of the gravitational wave G298048 in NGC4993.
  68. LIGO/Virgo G298048: Rapid Evolution of Possible Counterpart
  69. LIGO/Virgo G298048: Observed fading of optical counterpart SSS17a
  70. LIGO/Virgo G298048: Continued observation for DLT17ck
  71. LIGO/VIRGO G298048: Expansion Velocity of SSS17a Consistent With Relativistic Merger Ejecta
  72. LIGO/Virgo G298048: optical spectral energy distribution of SSS17a
  73. LIGO/Virgo G298048: ATCA upper limits on radio emission from optical source SSS17a in NGC 4993
  74. LIGO/Virgo G298048: Continued Swift UV and X-ray Monitoring of SSS17a
  75. LIGO/Virgo G298048: Archival VLA observations
  76. LIGO/Virgo G298048: Moderate dimming or no brightening of the optical counterpart candidate?
  77. LIGO/Virgo G298048: Brightening of Possible Counterpart
  78. LIGO/Virgo G298048: AGILE-GRID analysis of the potential counterpart field
  79. LIGO/Virgo G298048: Observation of the potential optical counterpart in NGC 4993
  80. LIGO/Virgo G298048: Subaru HSC z-band photometry of the possible optical counterpart
  81. LIGO/Virgo G298048: SkyMapper uvgri photometry of the candidate in NGC 4933
  82. LIGO/Virgo G298048: ATCA detection of a radio source coincident with NGC 4993
  83. LIGO/Virgo G298048: Likelihood of SSS17a Being an Unrelated Extragalactic Transient in NGC 4993
  84. LIGO/Virgo G298048: REM optical/NIR observations
  85. LIGO/Virgo G298048, Fermi GBM trigger 524666471/170817.529: MAXI/GSC observations
  86. LIGO/Virgo G298048: Pan-STARRS detections and izy photometry of the possible optical/NIR counterpart in NGC4993
  87. LIGO/Virgo G298048: Gemini-South Near-Infrared Photometry of the Optical Transient Candidate
  88. LIGO/Virgo G298048: Magellan g-band Imaging of the Potential Optical Counterpart Associated with NGC 4993
  89. LIGO/VIRGO G298048: Swift UVOT detection and XRT upper limits
  90. LIGO/Virgo G298048: Subaru HSC follow-up observations
  91. LIGO/Virgo G298048: VLA Refined Analysis
  92. LIGO/VIRGO G298048: Magellan Optical Spectrum of the Potential Optical Counterpart Associated with NGC 4993
  93. LIGO/Virgo G298048: VLA Detection
  94. LIGO/Virgo G298048: VISTA/VIRCAM detection of candidate counterpart
  95. LIGO/Virgo G298048: Galaxy-Targeted Optical Followup With Las Cumbres Observatory
  96. LIGO/Virgo G298048: Optical Candidate Shows No Evidence for Previous Activity in Archival SkyMapper Transient Survey Data
  97. LIGO/VIRGO G298048: The Potential Optical Counterpart in NGC 4993 Has Afterglow-Like Colors
  98. LIGO/Virgo G298048: Las Cumbres Observatory Detection of The Possible Optical Counterpart in NGC 4993
  99. LIGO/Virgo G298048: Inspection of archival HST data at the position of the potential optical counterpart
  100. LIGO/Virgo G298048: Nearby Galaxies in the Localization Volume using the updated sky map computed using LALInference

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