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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"

16152 results found.

  1. GRB 150925A: Swift/UVOT Upper Limits
  2. LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
  3. LIGO/Virgo G184098: optical transient search with Kiso Schmidt telescope and KWFC on behalf of J-GEM collaboration
  4. LIGO/Virgo G184098: TAROT network optical observations
  5. LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
  6. LIGO/Virgo G184098: Keck II DEIMOS Spectra of iPTF Optical Candidates
  7. LIGO/Virgo G184098: iPTF Optical Transient Candidates
  8. LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
  9. GRB 150910A: AAO optical observations
  10. GRB 150915A: NOT observations of a brightening afterglow
  11. GRB 150915A: Swift UVOT upper limits
  12. GRB 150910A: Mt. Terskol observatory optical observations
  13. GRB 150910A: TSHAO optical observations
  14. GRB 150915A: VLT/X-shooter redshift
  15. GRB 150915A: GROND detection of an optical counterpart candidate
  16. GRB 150915A: MASTER-NET optical observations
  17. GRB 150910A: Continued RATIR Observations
  18. GRB 150912A: Swift-XRT and UVOT observations
  19. GRB 150910A: Mt. Terskol observatory optical observation
  20. GRB 150912A: MITSuME Ishigakijima upper limits
  21. GRB 150911A: WHT optical imaging
  22. GRB 150910A: RATIR Observations
  23. GRB 150910A: MITSuME Ishigakijima Optical Observation after 2 days
  24. GRB 150912A: MASTER-IAC optical observations
  25. GRB150910A: P60 Observations
  26. GRB 150911A: Swift/UVOT Upper Limits
  27. GRB 150910A: AAO optical observations
  28. GRB 150910A: MITSuME Ishigakijima Optical Observation after 1 day
  29. GRB 150910A: Chuguev observatory optical observations
  30. GRB 150911A: MITSuME Okayama upper limits
  31. GRB 150910A: VLA Detection
  32. GRB 150910A: continued SAO RAS optical observations
  33. GRB 150910A: TSHAO optical observations
  34. GRB 150910A: NOT observations of the afterglow
  35. GRB 150910A: GROND observation of the afterglow
  36. GRB 150910A: MITSuME Ishigakijima Optical Observation
  37. GRB 150910A: SAO RAS optical photometry
  38. GRB 150910A: Kast spectroscopy from 3m Shane telescope
  39. GRB 150910A: Nanshan optical observations
  40. GRB 150910A: MITSuME Okayama Optical Observation
  41. GRB 150910A: LCOGT FTN afterglow observations
  42. GRB 150910A: KAIT Optical Afterglow Detection
  43. GRB 150910A: Swift detection of a burst with an optical afterglow
  44. Short GRB 150906B: proximity to NGC 3313 galaxy group
  45. GRB150907A: Swift/UVOT observations
  46. GRB 150907B: MASTER-SAAO early optical observations
  47. GRB 150818A: TSHAO and SAO RAS optical observations
  48. ANTARES neutrino detection: CAHA photometry & spectroscopy of the Swift source
  49. ANTARES neutrino Alert150901.32 alert and Swift XRT counterpart: MASTER optical observations and new possible candidate
  50. ANTARES neutrino detection and Swift/XRT counterpart: GMG observation
  51. GRB 150902A: Swift/UVOT Upper Limits
  52. ANTARES neutrino detection: Optical/NIR spectroscopy of the Swift/XRT counterpart candidate from NOT
  53. GRB 150902A: MASTER-SAAO optical observations
  54. GRB 150831B: Swift/UVOT Upper Limits
  55. GRB 150831B: MASTER-IAC early optical observations
  56. GRB 150831A: Swift/UVOT Upper Limits
  57. GRB 150831A: optical upper limit ISON-SSO
  58. GRB 150818A: possible SN rise in light curve of Mondy observations
  59. GRB 150821A: LCOGT Siding Springs early observations
  60. GRB 150821A: LCOGT Sutherland observations
  61. GRB 150821A: GROND afterglow observations
  62. GRB 150819A: Mondy and TSHAO optical upper limits
  63. GRB 150818A: continued Mondy optical observations
  64. GRB 150821A: VLT/X-shooter redshift
  65. GRB 150821A: Swift detection of a burst with an optical afterglow
  66. GRB 120729A: KAIT Optical Observations
  67. KAIT Optical Upper Limits for GRB 120422A, 120724A, 120803B, 120911A, and 120923A
  68. GRB 150818A: Mondy optical observations
  69. GRB150819A: NOT imaging
  70. GRB 150818A: Continued NOT monitoring - afterglow confirmation
  71. GRB 150818A: 10.4m GTC spectroscopy and host galaxy
  72. GRB 150818A: Mondy optical observations
  73. GRB 150818A: MITSuME Ishigakijima upper limits
  74. GRB 150819A: RATIR Optical Observations
  75. GRB 150818A: MITSuME Akeno optical upper limits
  76. GRB 150819A: MASTER-IAC early upper limit
  77. GRB 150819A: Swift/UVOT Upper Limits
  78. GRB150818A: NOT imaging
  79. GRB 150817A: AAO optical observations
  80. GRB 150817A: LCOGT observations
  81. GRB 150817A: Continued RATIR Optical Observations - Afterglow Confirmation
  82. GRB 150817A: P60 Observations
  83. GRB 150817A: Swift/UVOT Upper Limits
  84. GRB 150817A: RATIR Optical Afterglow Candidate
  85. GRB 150811A: Continued RATIR Observations
  86. GRB 150811A: KAIT Refined Analysis
  87. GRB 150811A: VLA Detection
  88. GRB 150811A: Swift/UVOT further observations
  89. GRB 150811A: SAO RAS optical observations
  90. GRB 150811A: P60 Observations
  91. GRB 150811A: LCOGT-McDonald afterglow detection
  92. GRB 150811A: Swift/UVOT Detection
  93. GRB 150811A: KAIT optical candidate
  94. GRB 150811A: RATIR Optical Afterglow Detection
  95. Fermi GBM GRB Trigger 460608875: iPTF P48 Observations
  96. GRB 150728A: TNG optical observations
  97. GRB 150801B: Swift/UVOT Upper Limits
  98. Fermi GBM GRB Trigger 458852670: iPTF P48 Observations
  99. GRB 150721A (Fermi GBM Trigger 459150552): iPTF P48 Observations
  100. GRB 150424A: HST imaging

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