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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').
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.

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

20957 results found.

  1. GRB 151111A: GROND confirmation of the afterglow and photometric redshift estimate
  2. GRB 151112A: Swift/UVOT Upper Limits
  3. GRB 151112A: GROND Detection of the Optical/NIR Afterglow Candidate
  4. GRB 151112A: initial UVOT observations
  5. GRB 151112A: Swift-XRT observations
  6. GRB 151111A: Swift/UVOT upper limits
  7. GRB 151111A: GROND marginal detection of a afterglow candidate
  8. LIGO/Virgo G194575: VLA follow-up
  9. GRB 151111A: LCOGT-FTS afterglow observations
  10. GRB 151107B: MASTER-NET OT detection inside the FERMI error box
  11. GRB 151027A: continued Mondy optical observations
  12. LIGO/Virgo G194575: Liverpool Telescope observations of iPTF-15dld and iPTF-15dni
  13. LIGO/Virgo G194575: La Silla QUEST, Pan-STARRS and PESSTO observations of iPTF15dld
  14. LIGO/Virgo G194575: Swift observations if iPTF15dld
  15. GRB 151027A: Hankasalmi optical observations
  16. LIGO/Virgo G194575: INAF-TNG/Asiago Telescope follow-up of iPTF15dld
  17. GRB 151107A: MASTER-NET optical observations
  18. LIGO/Virgo G194575: INAF-Asiago Telescope further analysis of iPTF candidates
  19. Swift-BAT triggers are disabled
  20. LIGO/Virgo G194575: INAF-Asiago Telescope follow-up of iPTF candidates
  21. LIGO/Virgo G194575: VLA follow-up
  22. GRB 151027A: Mondy optical observations
  23. GRB 150910A: CrAO optical observations
  24. GRB 151027A: Correction to GCN 18519
  25. GRB 151031A: GROND observation
  26. LIGO/Virgo G194575: LT Spectroscopy of iPTF candidates
  27. GRB 151031A: Swift/UVOT Detection
  28. GRB 151031A: VLT/X-shooter optical counterpart and redshift
  29. GRB 151027A: optical follow-up observations
  30. GRB 151027A: Continued P60 Monitoring
  31. GRB 151029A: Swift/UVOT Detection
  32. GRB 151029A: LCOGT-FTS afterglow observations
  33. GRB 151027B: Swift UVOT detection
  34. LIGO/Virgo G194575: VLA follow-up
  35. GRB 151027A: MAXI/GSC detection
  36. GRB 151029A VLT/X-shooter redshift
  37. GRB 151029A: GROND afterglow observations
  38. GRB 151027A: SAO RAS optical observations
  39. GRB 151027B: LCOGT FTN afterglow observations
  40. GRB 151027A: NOT optical and NIR observations
  41. GRB 151027A: T100 observations
  42. GRB 151027B: Swift/UVOT Upper Limits
  43. GRB 151027A : Xinglong TNT optical observation
  44. GRB 151027A: continued GMG observation
  45. GRB 151027B: RATIR Observations
  46. GRB 151027B: MASTER-NET early OT detection
  47. GRB 151027A: LCOGT-McDonald afterglow observations
  48. GRB 151027A: VLA detection
  49. GRB 151027B: GROND Optical/NIR Afterglow Detection
  50. GRB 151027B: VLT/X-shooter redshift
  51. GRB 151027A: THO optical observations
  52. GRB 151027A: UVOT Observations
  53. GRB 151027B: NOT optical afterglow candidate
  54. LIGO/Virgo G194575: iPTF Optical Transient Candidates
  55. GRB 151027A: Early RAPTOR Observations
  56. LIGO/Virgo G194575: MASTER Optical Inspection
  57. GRB 151027A: GMG observation
  58. LIGO/Virgo G194575: Swift observations of LSQ15bjb
  59. LIGO/Virgo G194575: GROND multi-color observations
  60. GRB 151027A: Weihai optical observations
  61. LIGO/Virgo G194575: further Pan-STARRS observations of the RA=1hr localisation region
  62. GRB 151027A: P60 afterglow confirmation and rebrightening
  63. GRB 151027A: KAIT optical afterglow confirmation
  64. LIGO/Virgo G194575: ASKAP followup
  65. LIGO/Virgo G194575: INAF-TNG follow-up of LSQ15bjb
  66. LIGO/Virgo G194575 : La Silla - QUEST followup
  67. GRB 151021A: Skynet PROMPT-CTIO/DSO17 observations of the optical afterglow
  68. LIGO/Virgo G194575: Near-infrared follow-up with OAO-WFC
  69. LIGO/Virgo G194575: Kanata/J-GEM optical follow-up
  70. LIGO/Virgo G194575: Pi of the Sky observations
  71. LIGO/Virgo G194575: MAXI/GSC observations
  72. LIGO/Virgo G194575: Swift observations
  73. GRB 151022A: OSN optical upper limit
  74. GRB 151023A: RATIR Observations
  75. GRB 151023A: Swift/UVOT Upper Limits
  76. GRB 151023A
  77. LIGO/Virgo G194575: CQUEAN/LOAO observations
  78. LIGO/Virgo G194575: LOFAR follow-up
  79. GRB 151022A: Swift/UVOT Upper Limits
  80. LIGO/Virgo G194575: RATIR Observations of Nearby Galaxies in the 1sigma Error Region
  81. LIGO Virgo G194575: MWA Observations
  82. LIGO/Virgo G194575: RATIR Observations of Nearby Galaxies in the 1sigma Error Region
  83. LIGO/Virgo G194575: more details on transients from Pan-STARRS in the RA=1hr localisation region
  84. LIGO/Virgo G194575: Fermi GBM Observations
  85. LIGO/Virgo G194575: Mini-MegaTORTORA observations
  86. LIGO/Virgo G194575: transients from Pan-STARRS in the RA=1hr localisation region
  87. LIGO Virgo G194575: TZAC TAROT observations
  88. GRB 151022A: MITSuME Okayama Ks-band upper-limit
  89. GRB 151022A: MASTER-Ural observations
  90. GRB 151021A: MITSuME Okayama Ks-band upper-limit
  91. GRB 151021A: Swift/UVOT Detection
  92. LIGO/Virgo G184098: LOFAR follow-up
  93. GRB 151004A: Swift-XRT follow-up observations
  94. Trigger 659734: Swift detection of SAX J1750.8-2900 or other source near Galactic center
  95. LIGO/Virgo G184098: VLA follow-up of iPTF15cyk
  96. LIGO/VIRGO G184098 : PESSTO classifications of PanSTARRS transients in the northern region
  97. GRB 151006A: OSN optical upper limit
  98. GRB 151006A: MITSuME Okayama Ks-band upper-limit
  99. GRB 151006A: Swift/UVOT Upper Limits
  100. LIGO/Virgo G184098: Further VST-ESO PARANAL observations

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