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Proposal Identification No.:

P3033 Arecibo Observatory

Date Received: 2015-Sep-01 10:35:28 William E. Gordon Telescope Observing Time Request COVER SHEET

Section I - General Information
Submitted for Sep 1 2015. This proposal has not been submitted before. Proposal Type: General Category: Observation Category: Time Requested this semester: Hours Next Semester: Hours already used for this pro ject: Additional Hours required to complete pro ject: Minimum Useful Time: Expected Data Storage: Prop osal Title: ABSTRACT: Regular Pulsars Galactic 50 50 0 0 1 hour 100-500 GB

Continuation of timing observations of the planets pulsar, PSR B1257+12

We have recently completed 50-day, high-cadence timing observations of the planets pulsar, PSR B1257+12, using the PUPPI pulsar backend. The data analysis has revealed that the orbit of the inner, 25-day period planet in the system has a 0.3 eccentricity. This places new constraints on the origin of the pulsar planets, and may shed new light on the poorly understood mechanism of neutron star planet formation. We propose to continue medium-cadence, multifrequency timing observations of PSB B1257+12 for one year, sampling the pulse arrival times once a week. With the much improved, 0.5 microsecond timing precision of this pulsar, we will revise orbital parameters of the inner planet, and place much tighter constraints on a possible presence of any additional, very low-mass bodies in the system. Combining the new data with the large database of measurements, dating back to 1991, we will be in position to look for long-term timing effects that could be due to a distant companion. Outreach Abstract: The inner, Moon-mass planet orbiting the millisecond pulsar, PSR B1257+12, once very 25 days, remains the lowest mass body discovered around a star other than the Sun. Our recent Arecibo observations have revealed that, contrary to the result of our previous, much less precise measurements, the orbit of this planet has a very significant ellipticity. This indicates that the planet' s orbit must have undergone a significant evolution in the early phase of the existence of this three-planet system. The observed ellipticity of the orbit could be induced by the planet' s gravitational interaction with the two outer, more massive planets, and/or a possible presence of another inner or very distant companion. In order to better understand the PSR B1257+12 planetary system and planet formation around neutron stars, we propose to continue Arecibo observations of the pulsar for one year, using the new pulsar backend, called PUPPI, which offers a much improved precision of timing measurements.

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Name Alex Wolszczan Andrew D Seymour

Institution Penn State University Arecibo Observatory

E-mail alex@astro.psu.edu aseymour@naic.edu

Phone 814 863 1756 787 878 2612

Student no no

Additional Authors
Rudy Rivera Soto, UPR, Mayaguez, undergraduate student, email: rudy.rivera@upr.edu

This work is not part of a thesis.

Remote Observing Request

X

Observer will travel to AO Remote Observing In Absentia (instructions to operator)

Section I I - Time Request
The following times are in LST. For these observations night-time is not needed.

Begin ­ End Interval­Interval 12:00 ­ 14:00 ­ ­ ­

Days Needed at This Interval 25

Time Constraints (Must Be Justified in the Prop osal Text) Observations should be conducted approximately once a week. This will ensure a proper cadence of timing measurements.

Next Semester Time Request

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Begin ­ End Interval­Interval 12:00 ­ 14:00 ­ ­ ­

Days Needed at This Interval 25

Time Constraints (Must Be Justified in the Prop osal Text) Observations should be conducted approximately once a week. This will ensure a proper cadence of timing measurements.

Section I I I - Instruments Needed
430 G L-wide 327

Atmospheric Observation Instruments:

Sp ecial Equipment or setup:

none

Section IV - RFI Considerations Frequency Ranges Planned

This proposal requires coordination with Punta Salinas radar within the band 1222-1381 MHz.. This proposal requires coordination with GPS L3 at 1381 MHz.

Section V - Observing List Target List
RA = 13:00:03.1 Dec = 12:40:55.6 Rise = 11:42 Set = 14:19

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