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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"

21012 results found.

  1. LIGO/VIRGO G298048: INAF VST-ESO PARANAL observations
  2. LIGO/Virgo G298048: KMTNet and other optical follow-up observations
  3. LIGO/Virgo G298048: further REM optical/NIR observations of candidate in NGC 4993
  4. LIGO/Virgo G298048: Subaru HSC z-band photometry confirms the fading nature of SSS17a
  5. LIGO/Virgo G298048: VLT linear polarimetry
  6. LIGO/Virgo G298048: GRAWITA VLT/X-shooter observations
  7. LIGO/Virgo G298048: NOT near-infrared observations of SSS17a
  8. LIGO/Virgo G298048: Further Pan-STARRS izy photometry confirms rapid fading of SSS17a/DLT17ck in i and z bands
  9. LIGO/Virgo G298048: Further VLA Observations
  10. LIGO/Virgo G298048: VLBA observations of the possible counterpart SSS17a in NGC 4993
  11. LIGO/Virgo G298048: MASTER photometry of the SSS17a in NGC 4993
  12. LIGO/Virgo G298048: HSC observations of the OT candidate of G298048
  13. LIGO/Virgo G298048: GROND photometry of candidate optical counterpart reveals brightening in the NIR
  14. LIGO/Virgo G298048: Additional Swope Observations of SSS17a
  15. LIGO/VIRGO G298048: ePESSTO optical spectra of the candidate optical/NIR counterpart of the gravitational wave G298048 in NGC4993.
  16. LIGO/Virgo G298048: Rapid Evolution of Possible Counterpart
  17. LIGO/Virgo G298048: Observed fading of optical counterpart SSS17a
  18. LIGO/Virgo G298048: Continued observation for DLT17ck
  19. LIGO/Virgo G298048: Archival 2MASS and Spitzer non-detections of the potential LIGO EM counterpart SSS17a
  20. LIGO/Virgo G298048: ATCA upper limits on radio emission from optical source SSS17a in NGC 4993
  21. LIGO/Virgo G298048: Continued Swift UV and X-ray Monitoring of SSS17a
  22. LIGO/Virgo G298048: Archival VLA observations
  23. LIGO/Virgo G298048: New MASTER observations of the OT in NGC 4993
  24. LIGO/Virgo G298048: Brightening of Possible Counterpart
  25. LIGO/Virgo G298048: Observation of the potential optical counterpart in NGC 4993
  26. LIGO/Virgo G298048: Subaru HSC z-band photometry of the possible optical counterpart
  27. LIGO/Virgo G298048: ATCA detection of a radio source coincident with NGC 4993
  28. LIGO/Virgo G298048: TZAC TAROT Reunion (TRE) observations
  29. LIGO/Virgo G298048: Likelihood of SSS17a Being an Unrelated Extragalactic Transient in NGC 4993
  30. LIGO/Virgo G298048: REM optical/NIR observations
  31. LIGO/Virgo G298048, Fermi GBM trigger 524666471/170817.529: MAXI/GSC observations
  32. LIGO/Virgo G298048: HCT observations
  33. LIGO/Virgo G298048: Pan-STARRS detections and izy photometry of the possible optical/NIR counterpart in NGC4993
  34. LIGO/Virgo G298048: Gemini-South Near-Infrared Photometry of the Optical Transient Candidate
  35. LIGO/Virgo G298048: Magellan g-band Imaging of the Potential Optical Counterpart Associated with NGC 4993
  36. LIGO/VIRGO G298048: Swift UVOT detection and XRT upper limits
  37. LIGO/Virgo G298048: Subaru HSC follow-up observations
  38. LIGO/Virgo G298048: VLA Refined Analysis
  39. LIGO/VIRGO G298048: Magellan Optical Spectrum of the Potential Optical Counterpart Associated with NGC 4993
  40. LIGO/Virgo G298048: MASTER observations of the NGC 4993
  41. LIGO/Virgo G298048: VLA Detection
  42. LIGO/Virgo G298048: VISTA/VIRCAM detection of candidate counterpart
  43. LIGO/Virgo G298048: Galaxy-Targeted Optical Followup With Las Cumbres Observatory
  44. LIGO/Virgo G298048: Optical Candidate Shows No Evidence for Previous Activity in Archival SkyMapper Transient Survey Data
  45. LIGO/VIRGO G298048: The Potential Optical Counterpart in NGC 4993 Has Afterglow-Like Colors
  46. LIGO/Virgo G298048: ATCA observations of candidate host galaxies
  47. LIGO/Virgo G298048: Optical Candidate Shows No Evidence for Previous Activity in Archival ASAS-SN Data
  48. LIGO/Virgo G298048: REM optical/NIR observations of candidate in NGC 4993
  49. LIGO/Virgo G298048: DECam optical candidate
  50. LIGO/Virgo G298048: Potential optical counterpart discovered by Swope telescope
  51. LIGO/Virgo G298048: AGILE GRID observations
  52. LIGO/Virgo G298048: AGILE MCAL observations
  53. LIGO/Virgo G298048: Insight-HXMT observations
  54. LIGO/Virgo G297595: Liverpool Telescope observations of MASTER transients
  55. LIGO/Virgo G298048: INTEGRAL detection of a prompt gamma-ray counterpart
  56. LIGO/Virgo G297595: Swift-XRT sources
  57. LIGO/Virgo G296853 TZAC TAROT observations
  58. LIGO/Virgo G297595: Konus-Wind observations
  59. LIGO/Virgo G297595: MASTER MASTER Bright PSN detection in error-box
  60. LIGO/Virgo G297595: INAF VST-ESO PARANAL observations
  61. LIGO/Virgo G297595: Subaru Hyper Suprime-Cam follow-up observations
  62. LIGO/Virgo G297595: REM optical/NIR observations
  63. LIGO/Virgo G297595 : MAXI/GSC observations
  64. GRB 170810A: VLA Detection
  65. LIGO/Virgo G297595: Pan-STARRS coverage and transients over the first 5hrs
  66. LIGO/Virgo G297595: Insight-HXMT observations
  67. LIGO/Virgo G297595: Fermi GBM Observations
  68. LIGO/Virgo G297595: AGILE GRID observations
  69. GRB 170813A: Swift/UVOT Upper Limits
  70. LIGO/Virgo G297595: INTEGRAL search for a prompt gamma-ray counterpart
  71. LIGO/Virgo G297595: AGILE MCAL observations
  72. LIGO/Virgo G297595: IceCube neutrino observations
  73. GRB 170813A: RATIR Optical and NIR Observations
  74. GRB 170728B: 15 GHz upper limits from AMI
  75. GRB 170728A: 15 GHz upper limits from AMI
  76. GRB 170714A: 15 GHz upper limits from AMI
  77. GRB 170711A: 15 GHz upper limits from AMI
  78. GRB 170710C: 15 GHz upper limits from AMI
  79. GRB 170710B: 15 GHz upper limits from AMI
  80. GRB 170626A: 15 GHz upper limits from AMI
  81. LIGO/Virgo G296853: BOOTES-1 and GTC optical observations
  82. LIGO/Virgo G296853: Insight-HXMT observations
  83. LIGO/Virgo G296853 : MAXI/GSC observations
  84. GRB 170810A: Swift/UVOT Detection
  85. GRB 170810A: MASTER-NET very bright OT detection
  86. LIGO/Virgo G296853: Super-AGILE observations
  87. LIGO/Virgo G296853: MASTER SN detection near center error-area
  88. GMRT upper limit on the radio afterglow of GRB 170728B
  89. LIGO/Virgo G296853: Fermi GBM Observations
  90. LIGO/Virgo G296853: AGILE GRID observations
  91. LIGO/Virgo G296853: MASTER follow up observations
  92. LIGO/Virgo G296853: AGILE MCAL observations
  93. LIGO/Virgo G296853: IceCube neutrino observations
  94. GRB 170728B: TShAO, SAO RAS and AbAO optical observations
  95. GRB 170804A: LCO Observations
  96. GRB 170804A: Swift/UVOT Detection
  97. GRB 170803A: Swift/UVOT Detection
  98. Swift Trigger 765783 is not an astrophysical event.
  99. GRB 170728B: Swift/UVOT Further Analysis
  100. GRB 170714A: Chandra observations

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