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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"

914 results found.

  1. LIGO/Virgo S190412m: Further J-GEM optical/NIR observations
  2. LIGO/Virgo S190426c: DG19ytre and DG19kplb 1.5m OSN imaging and 10.4m GTC spectroscopy
  3. LIGO/Virgo S190426c: RATIR Optical and NIR Observations of Galaxies
  4. GRB 190427A: MITSuME Akeno optical upper limits
  5. LIGO/Virgo S190425z: COATLI Observations of Galaxies
  6. LIGO/Virgo S190425z: RATIR Observations of Galaxies
  7. LIGO/Virgo S190412m: J-GEM optical/NIR follow-up observations
  8. GRB 190404C: MITSuME Akeno and Okayama optical upper limits
  9. LIGO-Virgo GW S190408an: J-GEM optical/NIR follow-up observations
  10. GRB 190330A: MITSuME Akeno and Okayama optical upper limits
  11. IceCube-190331A: MASTER optical follow-up observations
  12. GRB 190326A: MITSuME Okayama optical upper limits
  13. GRB190311A: MITSuME Akeno optical observation
  14. GRB 190311A: OSN optical afterglow detection
  15. IceCube-190221A: MASTER Global Robotic Net optical observation
  16. GRB 190219A: CAHA 2.2m observations
  17. GRB190211A: MITSuME Akeno optical observation
  18. GRB190123A: MITSuME Akeno optical upper limits
  19. GRB190109B: MITSuME Akeno optical upper limits
  20. GRB 190114B: MITSuME Akeno optical upper limits
  21. GRB 190114A: OSN Detection
  22. GRB 190106A: OSN Afterglow Observations
  23. GRB190109A: MITSuME Akeno optical upper limits
  24. GRB 190106A: MITSuME Akeno optical observation
  25. IceCube-190104A: MASTER optical observation
  26. GRB 181228A: MITSuME Akeno optical upper limits
  27. GRB 181110A: MITSuME Akeno optical observation
  28. GRB 181103A: MITSuME Okayama optical upper limits
  29. GRB 181022A: MITSuME Akeno optical upper limits
  30. GRB 181011A: MITSuME Akeno and Okayama optical upper limits
  31. GRB 180914B: OSN Detection and light curve/SED analysis
  32. GRB 180905A: MITSuME Akeno optical upper limits
  33. GRB 180904A: OSN observations
  34. GRB 180728A: classification of the associated SN 2018fip
  35. GRB 180728A: discovery of the associated supernova
  36. GRB 180721A: MITSuME Akeno optical upper limits
  37. GRB 180720B: MITSuME Ishigaki optical observations
  38. GRB 180706A: OSN detection
  39. GRB 180720B: MITSuME Akeno optical observations
  40. IceCube-171106A: MASTER optical observation
  41. GRB 180705A: OSN observations
  42. GRB 180624A: MITSuME Okayama optical upper limits
  43. GRB 180602A: MITSuME Ishigakijima optical upper limits
  44. GRB 180602A: MITSuME Akeno optical upper limits
  45. GRB 180602A: MITSuME Okayama optical upper limits
  46. GRB 180514A: MITSuME Ishigakijima optical upper limits
  47. GRB 180514A: MITSuME Akeno optical upper limits
  48. GRB 180510A: MITSuME Ishigakijima optical upper limits
  49. GRB 180514A: 1.5m OSN optical observations
  50. GRB 180512A: Upper limits from OSN
  51. GRB 180418A: MITSuME Ishigakijima Optical Observation
  52. GRB 180410A: MITSuME Akeno optical upper limits
  53. GRB 180316A: MITSuME Akeno optical upper limits
  54. GRB 180316A: MITSuME Okayama optical upper limits
  55. GRB 180314A: MITSuME Okayama optical upper limits
  56. GRB 180204A: MITSuME Okayama optical upper limits
  57. GRB 180115A: MITSuME Akeno optical upper limits
  58. GRB 171205A: Detection of the emerging SN
  59. GRB 171123A: OSN Upper Limit
  60. GRB 171124A: MITSuME Akeno optical upper limits
  61. GRB 171123A: MITSuME Akeno optical upper limits
  62. GRB 171120A: MITSuME Akeno optical upper limits
  63. GRB 171115A: MITSuME Okayama optical upper limits
  64. GRB 171115A: MITSuME Akeno optical upper limits
  65. GRB 171102B: MITSuME Akeno optical upper limits
  66. GRB 171010A: MITSuME Akeno Optical Observation
  67. GRB 170921A: MITSuME Okayama upper limits
  68. GRB 170903A: MITSuME Okayama upper limits
  69. LIGO/Virgo G299232: GRAWITA Asiago optical observations
  70. LIGO/Virgo G299232: Nearby Galaxies in the Localization Volume
  71. GRB 170822A: MITSuME Akeno Optical Observation
  72. LIGO/Virgo G298048: ATCA 8.5 GHz observations of galaxies in the localisation volume
  73. LIGO/Virgo G298048: Nearby Galaxies in the Localization Volume using the updated sky map computed using LALInference
  74. LIGO/Virgo G298048: Nearby Galaxies in the Localization Volume with Face-on Assumption
  75. LIGO/Virgo G298048: Nearby Galaxies in the Localization Volume
  76. GRB 170728A: LCO observations
  77. GRB 170728B: I-band detection from 1.5m OSN
  78. GRB 170705A: MITSuME Akeno Optical Observation
  79. LIGO/Virgo G268556: optical observations and classification of Pan-STARRS1 transients
  80. GRB 170519A: MITSuME Akeno Optical Observation
  81. GRB 170519A: MITSuME Okayama Optical Observation
  82. LIGO/Virgo G277583: UH88/SNIFS classification of ATLAS and PS1 transients
  83. IceCube-170312A: MASTER follow-up observations
  84. LIGO/Virgo G277583: Asiago spectroscopic classification of ATLAS17byo and ATLAS17cgg
  85. GRB 170317A: MITSuME Okayama Optical Observation
  86. LIGO/Virgo G277583: ATLAS coverage and transients over the first 2 days
  87. LIGO/Virgo G275404: Nearby galaxy observations by J-GEM collaboration
  88. LIGO/Virgo G275404: Keck LRIS classification of MASTER PSN candidate
  89. LIGO/Virgo G274296: J-GEM optical/NIR follow-up observations
  90. GRB 170202A: MITSuME Akeno Optical Observation
  91. LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
  92. LIGO/Virgo G268556: Gemini spectra of Pan-STARRS1 transients
  93. LIGO/Virgo G268556: VLA follow-up of iPTF17cw
  94. LIGO/Virgo G268556: Liverpool Telescope Spectroscopy of iPTF17bv and iPTF17ck
  95. PESSTO follow-up of GRB 161219B/SN2016jca
  96. GRB161219B - Anticipated hyperluminal evidence
  97. GRB 161219B: Spectroscopic detection of the associated SN with OSIRIS/GTC
  98. GRB 161219B: MITSuME Akeno Optical Observation
  99. GRB 161217A: MITSuME Okayama upper limits
  100. GRB 161202A: MITSuME Okayama upper limits

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