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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"

21097 results found.

  1. GRB 230623A: Tiled Swift observations
  2. MAXI GRB 230623A: MASTER optical observations
  3. GRB 230623A: Tiled Swift observations
  4. GRB 230622A: ATCA rapid radio follow-up
  5. Swift GRB 230622A: Global MASTER-Net observations report
  6. LIGO/Virgo/KAGRA S230615az: LBT spectroscopic classification of GOTO23hn
  7. LIGO/Virgo S230622e: Global MASTER-Net observations report
  8. LIGO/Virgo S230621bq: Global MASTER-Net observations report
  9. LIGO/Virgo S230621ad: Global MASTER-Net observations report
  10. LIGO/Virgo/KAGRA S230615az: LBT spectroscopic redshift of the host galaxy of GOTO23hn
  11. ZTF23aaoohpy/AT2023lcr: SAO RAS observations
  12. Fermi trigger No 709083929: Global MASTER-Net observations report
  13. AT2023lcr: VLA radio detection
  14. ZTF23aaoohpy/AT2023lcr: Montarrenti Observatory optical observations
  15. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Upper limits from Konus-Wind observations
  16. LIGO/Virgo S230620ad: Global MASTER-Net observations report
  17. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Swift/UVOT detection
  18. LIGO/Virgo S230620au: Global MASTER-Net observations report
  19. ZTF23aaoohpy/AT2023lc: Mondy optical observations
  20. AT2023lcr: Neil Gehrels Swift Observatory X-ray detection
  21. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): Kinder observations with Lulin observatory and a probable plateau in the g-band light curve
  22. AT2023lcr: Pan-STARRS & ATLAS Observations
  23. ZTF23aaoohpy/AT2023lcr: Keck/LRIS spectroscopy and redshift
  24. ZTF23aaoohpy/AT2023lcr: Xinglong-2.16m optical observations
  25. LIGO/Virgo/KAGRA S230615az: Wendelstein observations of DESI galaxies and GIT candidates
  26. LIGO/Virgo S230620al: Global MASTER-Net observations report
  27. LIGO/Virgo S230620af: Global MASTER-Net observations report
  28. LIGO/Virgo S230620z: Global MASTER-Net observations report
  29. LIGO/Virgo S230620w: Global MASTER-Net observations report
  30. LIGO/Virgo S230619bg: Global MASTER-Net observations report
  31. LIGO/Virgo S230620g: Global MASTER-Net observations report
  32. LIGO/Virgo S230619ay: Global MASTER-Net observations report
  33. ZTF23aaoohpy/AT2023lcr: Liverpool Telescope detection
  34. ZTF23aaoohpy/AT2023lcr: OHP/T193 and OHP/T120 optical follow-up observations
  35. LIGO/Virgo S230619bd: Global MASTER-Net observations report
  36. LIGO/Virgo S230619bb: Global MASTER-Net observations report
  37. LIGO/Virgo S230619as: Global MASTER-Net observations report
  38. LIGO/Virgo S230619ap: Global MASTER-Net observations report
  39. ZTF23aaoohpy/AT2023lcr: GROWTH-India Telescope follow-up observations
  40. GRB 230618A: Osservatorio Astronomico Nastro verde upper limit
  41. ZTF23aaoohpy/AT2023lcr: GOTO early optical observations and constraint
  42. ZTF23aaoohpy/AT2023lcr: Zwicky Transient Facility discovery of a fast fading red transient
  43. LIGO/Virgo S230619i: Global MASTER-Net observations report
  44. LIGO/Virgo/KAGRA S230615az: GRANDMA observations of GOTO and GIT candidates
  45. LIGO/Virgo S230619aa: Global MASTER-Net observations report
  46. LIGO/Virgo S230619x: Global MASTER-Net observations report
  47. LIGO/Virgo S230619e: Global MASTER-Net observations report
  48. LIGO/Virgo S230618at: Global MASTER-Net observations report
  49. LIGO/Virgo S230618ba: Global MASTER-Net observations report
  50. LIGO/Virgo S230618az: Global MASTER-Net observations report
  51. LIGO/Virgo S230618ae: Global MASTER-Net observations report
  52. LIGO/Virgo S230618aq: Global MASTER-Net observations report
  53. LIGO/Virgo S230618y: Global MASTER-Net observations report
  54. LIGO/Virgo S230618s: Global MASTER-Net observations report
  55. GRB 230618A: Swift/UVOT Upper Limits
  56. GRB 230616A: Swift-XRT observations
  57. LIGO/Virgo S230618r: Global MASTER-Net observations report
  58. LIGO/Virgo S230616aa: Global MASTER-Net observations report
  59. LIGO/Virgo S230615an: Global MASTER-Net observations report
  60. LIGO/Virgo S230615ak: Global MASTER-Net observations report
  61. GRB 230618A: KAIT Optical Observations
  62. LIGO/Virgo S230617ba: Global MASTER-Net observations report
  63. LIGO/Virgo S230618k: Global MASTER-Net observations report
  64. LIGO/Virgo S230618d: Global MASTER-Net observations report
  65. LIGO/Virgo S230617bc: Global MASTER-Net observations report
  66. LIGO/Virgo S230617aq: Global MASTER-Net observations report
  67. LIGO/Virgo S230617ab: Global MASTER-Net observations report
  68. Swift GRB 230618A: Global MASTER-Net observations report
  69. LIGO/Virgo S230617aj: Global MASTER-Net observations report
  70. GRB230618A: LCOGT Optical Observations
  71. GRB 230616A: Swift ToO observations
  72. LIGO/Virgo/KAGRA S230615az: T80S Search and Candidate Counterpart Identification
  73. LIGO/Virgo/KAGRA S230615az: Non-Detections of GROWTH-India Candidates from GECKO Optical Observations
  74. LIGO/Virgo/KAGRA S230615az: Xinglong-2.16m photometric observations of GIT candidates
  75. LIGO/Virgo/KAGRA S230615az: GOTO candidate counterparts
  76. LIGO/Virgo S230616s: Global MASTER-Net observations report
  77. LIGO/Virgo S230615be: Global MASTER-Net observations report
  78. LIGO/Virgo S230615af: Global MASTER-Net observations report
  79. LIGO/Virgo S230616j: Global MASTER-Net observations report
  80. LIGO/Virgo S230615av: Global MASTER-Net observations report
  81. LIGO/Virgo S230615az: Global MASTER-Net observations report
  82. LIGO/Virgo S230615ax: Global MASTER-Net observations report
  83. LIGO/Virgo S230615k: Global MASTER-Net observations report
  84. LIGO/Virgo S230615t: Global MASTER-Net observations report
  85. LIGO/Virgo S230615i: Global MASTER-Net observations report
  86. LIGO/Virgo S230613at: Global MASTER-Net observations report
  87. LIGO/Virgo S230614ac: Global MASTER-Net observations report
  88. LIGO/Virgo S230614t: Global MASTER-Net observations report
  89. LIGO/Virgo S230614o: Global MASTER-Net observations report
  90. Fermi trigger No 708426906: Global MASTER-Net observations report
  91. GRB 230606A: LCOGT Optical Observations
  92. LIGO/Virgo S230611be: Global MASTER-Net observations report
  93. LIGO/Virgo S230611l: Global MASTER-Net observations report
  94. LIGO/Virgo S230609u: Global MASTER-Net observations report
  95. LIGO/Virgo S230608aw: Global MASTER-Net observations report
  96. LIGO/Virgo S230608as: Global MASTER-Net observations report
  97. LIGO/Virgo S230609a: Global MASTER-Net observations report
  98. LIGO/Virgo S230608ah: Global MASTER-Net observations report
  99. LIGO/Virgo S230608q: Global MASTER-Net observations report
  100. ZTF23aamxeqf/AT2023jxk: 1.3m DFOT Optical upper limit

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