Identification

Title

The magnetic future of the Sun

Abstract

We analyze space-and ground-based data for the old (7.0 +/- 0.3 Gyr) solar analogs 16 Cyg A and B. The stars were observed with the Cosmic Origins UV Spectrographs on the Hubble Space Telescope (HST) on 2015 October 23 and 2016 February 3, respectively, and with the Chandra X-ray Observatory on 2016 February 7. Time-series data in Ca II data are used to place the UV data in context. The UV spectra of 18 Sco (3.7. +/-. 0.5 Gyr), the Sun (4.6. +/-. 0.04 Gyr), and a Cen A (5.4(-0.2)(+1.2) Gyr) appear remarkably similar, pointing to a convergence of magnetic heating rates for G2 main-sequence stars older than approximate to 2-4 Gyr. But the B component's X-ray (0.3-2.5 keV) flux lies 20x below a well-known minimum level reported by Schmitt. As reported for a. Cen. A, the coronal temperature probably lies below that detectable in soft X-rays. No solar UV flux spectra of comparable resolution to those of stellar data exist, but they are badly needed for comparison with stellar data. Center-to-limb variations are reevaluated for lines such as Ca II through X-rays, with important consequences for observing activity cycles in such features. We also call into question work that has mixed solar intensity-intensity statistics with flux-flux relations of stars.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7vh5rdf

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2017-10-10T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact